Lactose is a healthy carbohydrate commonly available in milk and milk products. It has two simpler sugar units, namely glucose and galactose. Lactose improves the absorption of calcium, which is essential for your bone health. Additionally, lactose is the only source of galactose, a simple sugar that is necessary for good brain function and a healthy immune system.
Lactose intolerance occurs when lactose is not digested well by our digestive system.
When we say that the food is digested in our stomach, it is to be understood that the food that we take in is broken down into smaller pieces so that the body can absorb them. In the mouth, the breakdown occurs as we chew the food, but in the stomach, the food is broken down through chemical reactions. This process is aided by certain proteins known as enzymes.
One such enzyme is lactase. This is responsible for breaking down lactose molecules. Any deficiency in this enzyme would ultimately prevent lactose from being digested, thereby causing lactose intolerance.
When lactose intolerant people consume dairy products, they’re usually faced with unpleasant gastrointestinal (stomach and intestines) symptoms. Some of the symptoms that occur immediately include:
It is believed that a few thousand ago, only infants were able to digest lactose, and as they grew, they began losing the lactase enzyme. In other words, all adults were lactose intolerant.
But around 8,000 years ago in what's now Turkey — just when humans were starting to milk newly domesticated cows, goats, and sheep — changes in the gene responsible for producing lactase appeared more frequently. Around the same time, adult lactose tolerance developed. But of course, not the entire population was lactose tolerant. There were still human adults who were lactose intolerant.
But how did lactose tolerance continued to prevail?
An evolutionary geneticist, Mark Thomas, seems to think that it is the combination of famine and 'deadly diarrhea.' In times of famine, where the crops failed, the consumption of milk probably increased. While it may just cause some gastrointestinal disturbances in the intolerant, it can be deadly for the malnourished. So, the lactose tolerant people had a better survival advantage at this time and were more likely to pass on the gene that ensured the ability to consume dairy.
The LCT gene is responsible for producing the lactase enzyme, which degrades the lactose molecules. This LCT gene is controlled by another gene, the MCM6.
Located inside the long arm of chromosome 2, the MCM6 gene plays a governing role in our ability to digest milk products. A specific portion of the MCM6 gene - known as a regulatory element - helps control the activity (expression) of the LCT gene, thus influencing how much lactase is produced.
Also known as "C/T(-13910)" or just 13910T, rs4988235 is located in the MCM6 gene. However, it exerts its influence on the lactase-producing-LCT gene. The T allele of rs4988235 is the more common allele and enables the lactase enzyme production. So people who have the T allele are likely to be lactose persistent or lactose tolerant. The lactase activity is more in people with two T alleles than with one.
Lactose intolerance due to a deficiency of lactase enzyme in certain LCT gene types (genetic) is referred to as primary lactose intolerance. Secondary lactose intolerance, on the other hand, is caused by any illness or injuries. Any such conditions might affect your small intestine and lead to a reduction in lactase secretion. Celiac disease and Crohn’s disease are the two most common intestinal diseases linked to low lactase secretion.
Answering this question also partially solves the mystery of why, for some people, the genetic tests indicate lactose intolerance, despite them being able to consume dairy products without any issues.
Let’s take an example of a person who has been following a vegan lifestyle for a while now. Before taking up veganism, he could comfortably eat and digest dairy products. However, after a few years on a vegan diet, re-introducing dairy products in his diet is suddenly giving him digestive problems. So, what could have happened?
The cells that produce the enzyme to digest lactose (lactase) are present in the intestines and are few in number. When a person goes off-dairy for a while, there’s basically no work for these cells, and they temporarily disappear. When dairy is introduced back into the diet, the person may exhibit lactose intolerance for a while till these cells reappear.
Another factor that could explain this is our gut flora - the millions of bacteria present in our digestive tract. Some of these bacteria may help in breaking down lactose molecules. A diet that includes dairy products will offer a survival advantage to the bacteria that can digest lactose and will let them flourish better. On the other hand, these bacteria will not thrive for long when dairy is removed from the diet. When re-introducing dairy products, due to the lack of lactose-digesting-bacteria, the person may experience temporary lactose intolerance.
Gut bacteria is also the reason why many lactose-intolerant individuals can still consume up to a cup of milk per day.
If lactose-digesting bacteria dominate your gut flora, you may even be able to stick to a normal diet (that includes dairy) even if your gene does not produce lactase!
In fact, introducing some ‘good bacteria’ (with the ability to digest lactose) has been studied to improve and provide relief from lactose intolerance symptoms.
The incidence of lactose intolerance varies among different population groups. The population that’s the most affected with lactose intolerance is the East Asian descent, with 70-100% of the people affected.
On the other end is North European descent with 18-26% incidence due to their long-standing dependence on unfermented dairy products - the European ancestors may have nested in a place where dairy farming flourished and passed on the specific gene type that produces lactase.
Ethnicity also influences the age of onset of lactose intolerance.
Lactose intolerance in infancy is the most common in Finland - 1 in 60,000 newborns affected. In white people, intolerance develops in children older than five years. In African Americans, most children become intolerant by the age of two years.
A lactose-free diet is the best way to combat lactose intolerance. But before eliminating lactose from your diet, it is important to test your extent of intolerance. Research suggests that many people can have a cup of milk every day (12 grams of lactose) without any or very mild symptoms. This is important because dairy is a common source of vitamin D and calcium. So if you can tolerate a cup of milk a day, it's better to use it to your advantage.
But even if a hint of lactose in your diet puts you in trouble, then it is advisable to cut out dairy and all the other sources of lactose from your diet.
Some healthy food groups that are also lactose-free include:
Calcium and vitamin D are important for your bone health. Getting adequate levels of these nutrients when on a dairy-free diet can be challenging. Some food sources are naturally high in calcium and vitamin D. Finding a way to incorporate them into your diet can ensure good bone health.
The flavor you experience when you take a bite of your favorite food is a result of three sensory inputs:
- The tactile sensation of munching food
Gustation, another term for taste, helps us differentiate the chemicals present in the food. The organ for taste is the tongue.
Scientists generally describe human taste perception in terms of four qualities:
Different regions of the tongue pick up on different taste qualities. Some studies speculate the existence of other taste categories. A notable one would be “umami” - the taste given out by an amino acid glutamate, present in parmesan cheese, soy sauce, and tomatoes.
Upon chewing the food, various ‘bitter’ molecules (present in foods like cabbage and broccoli) are released in our mouth. Our tongue contains around 35 different proteins that detect and respond to bitter substances.
The usage of “to leave a bitter taste in one’s mouth” to describe unpleasant situations is no coincidence. There’s a reason why the word bitter is often used in a negative connotation. Despite the bitter taste found in healthy food like vegetables, most people still have a strong negative reaction. Why?
Our ancestors have not always been able to taste bitter foods. The bitter taste perception only evolved around 200 million years ago. Taste was a sense that aided our ancestors to predict the nature of the food they were consuming. Most poisonous compounds in nature are bitter. So, bitter meant poisonous - it indicated the presence of toxins.
Plants also adopted this trick to prevent the seeds from being eaten, a defense mechanism called “antifeedant” defense. By “faking” a bitter taste, the seeds had a better chance of germinating.
The healthy bitter foods we find today are the ones trying to fake being poisonous to prevent themselves from being eaten.
Thus, the development of bitter taste was a matter of survival. Individuals who had the proteins that could sense the bitter taste were able to detect toxins in their food. On the other hand, those who didn’t have the “bitter-tasting” proteins would ingest these toxins and die. The individuals who could taste bitter foods would also be able to pass these proteins to their offspring, thus increasing their survivability.
The sensitivity to better taste may have offered a survival advantage to our ancestors. But, in modern human society, it can be detrimental. The advent of agriculture resulted in the production of nutritious vegetables. Certain compounds in the vegetables, however, activate the bitter taste receptors. So the “bitter-tasting” proteins, which were supposed to protect us from toxic materials, now prevent some people from consuming vegetables by giving out an undesirable bitter taste.
TAS2R38 gene is located on chromosome 7 and encodes the protein taste receptor 38 - a bitter taste receptor. TAS2R38 influences the ability to taste both 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC) - both of these are chemically related compounds that elicit a bitter taste.
Insensitivity to the bitter-tasting compounds PROP and PTC has been proposed as a marker or an ‘indicating factor’ for individual differences in bitter taste perception that influence food preference and intake.
rs713598 is one of three important SNPs involved in the perception of bitter taste of molecules like PTC present in foods like broccoli and drinks like coffee.
According to a study, people with the CC and CG types of rs713598 showed sensitivity to PTC , while people with the GG type were unable to taste it.
Here, G is called the ‘non-tasting’ allele, and C is called the ‘tasting’ allele.
rs1726866 is an SNP in the TAS2R38 gene that influences the ability to perceive bitter taste.
The “C” allele of rs1726866 is strongly associated with increased taste sensitivity to PROP/PTC.
Here, *T is called the ‘non-tasting’ allele, and C is called the ‘tasting’ allele.
rs10246939 is an SNP that influences the sensitivity to the bitterness of PROP and PTC. People who have the CC and CT types are known to be sensitive to bitterness, while individuals with the TT type have lower bitterness intensity.
Here, T is called the ‘non-tasting’ allele, and C is called the ‘tasting’ allele.
People who are extremely sensitive to bitter taste are called Supertasters, while those who perceive little or no bitter taste are called Nontasters.
Many health vegetables like Brussel sprouts, broccoli, and cauliflowers are high in PROP and PTC. Being highly sensitive to these bitter flavors, supertasters are more likely to avoid these vegetables. Thus, the supertasters tend to miss out on nutrition and fiber from the vegetables.
Salt does an excellent job of masking bitter notes. So, supertasters may over-salt their dishes. Consuming excess salt (sodium) has been linked to many health risks like hypertension, heart disease, and stroke.
Burning Mouth Syndrome is characterized by a burning, scalding, or tingling feeling in the mouth. Supertasters have an unusually high density of taste buds, and as a result, the flavors are much more intense.
Bitter substances have a protective role against certain types of cancers, including colon cancer. Since supertasters tend to avoid bitter substances, they may be more susceptible to colon cancer.
On the brighter side, supertasters also find highly fatty or sugary foods less palatable than nontasters. They also tend to avoid excess alcohol consumption (because of the bitter taste) and smoking.
Lemon helps take away some of the bitterness from the vegetables.
Less bitter vegetables like squash, sweet potatoes, and corn are more palatable and high in nutrients.
Seasoning bitter vegetables like Brussel sprouts with salt and natural sweeteners can help mask the bitterness. However, it is important not to overdo the salt and sugar.
You must have heard people say that they have a ‘sweet tooth.’ They always tend to crave sugary drinks and foods. They may not even be able to complete a meal without a dessert.
So, what is this tendency to crave sweets? Is this some kind of addiction, or do these people actually need excess sugar to function actively?
People have specific likes and dislikes when it comes to taste. In fact, people are born with these likes and dislikes. One such strong like that many have is a preference for sweet foods.
Sweetness is a basic taste you get when you eat anything sugary. Any soluble carbohydrate that is used in foods and tastes pleasant belongs to this category.
There are also certain other substances that give a sweet taste. These are called non-sugar substitutes and include aspartame, saccharin, and other chemical sweeteners.
The taste threshold is the minimum concentration of a particular taste that people are able to easily identify.
Sweetness has the highest taste threshold. People identify and relate to sweetness easily and are trained to enjoy the taste all through life.
"## Is Sweet Tooth A Justified Condition?
Newer studies are confirming that sweet tooth can be an actual condition and not just an excuse to gorge on sweet treats!
A study that analyzed the data of about 6500 people from the Danish community concludes that a particular hormone secreted in the liver determines who loves sweet foods and who doesn’t.
More studies relate the FGF21 gene to an increase or decrease in the preference for sweet foods. (More about this in the genetic section)
How do our bodies react so positively to sweet foods? The minute you eat something sweet, the sweet receptors in the tastebuds identify the taste and send information to your brain.
It was recently discovered that human beings have taste receptors throughout the body, including the linings of the GI tract, the nasal epithelium, the respiratory system, and even in the testes and sperm!
As food enters the gut, the enteroendocrine cells identify sweetness. The amount of sweetness encountered by the enteroendocrine cells determines your hunger or feeling of fullness.
Leptin is a hormone secreted by the adipose tissues and in the small intestine. This hormone helps inhibit hunger and tells you that you can stop eating. Leptin ensures energy balance in the body.
Leptin and the signals from the sweet taste receptor cells work in coordination to identify whether you are full or not. Leptin levels are the highest around midnight and lowest in the afternoons. High leptin levels bring down sweet taste sensitivity.
Because of leptin level changes, certain foods that you feel are very sweet in the afternoon might feel just fine at night!
Most people crave sweet treats in the middle of the night because of this reason.
Imagine 8000 BC when cavemen were trying to make weapons and tools with stones. Cave paintings during that period show cavemen raiding beehives to get sweet honey.
Our sweet tooth and the tendency to prefer sweet foods date back to the stone age!
Sugar was produced in India very early. Around 2000 BC, Indians were already making sugar-coated milk-based sweets that they enjoyed during festivals and special occasions.
Romans started making gold-laced sweets called Kryksokolla in 600 AD. As sugar cultivation became popular around the world, the different kinds of sweet foods produced increased too.
Early primates searched and fought overripe fruits. Ripe fruits were full of sugar and gave the monkeys and apes an instant dose of energy that was very important in the wild. Scientists believe that we relate sweet foods to energy and survival and are still drawn to them subconsciously.
About two centuries ago, the average American consumed 2 pounds of sugar a year. Do you know the value now? It is a staggering 152 pounds a year!
Sugar comes in two distinct forms - natural sugars (found in fruits and vegetables) and added sugars (found in sweets, pastries, processed foods, beverages, and snacks). The recommended values of sugar mentioned below are for added sugars.
FGF21 gene - The FGF21 gene produces a hormone that regulates glucose metabolism in the body. The rs838133 SNP of the FGF21 gene creates changes in the tendency to prefer sweet foods. People with the A allele of this SNP have a higher tendency to prefer sweet foods than those with the G allele.
FTO Gene - This is called the Fat mass and obesity-associated gene. While variations in the gene directly affect weight gain, the rs1421085 SNP of the gene also seems to cause changes in preference to sweet foods. The C allele of the rs1421085 SNP makes an individual prefer sweetness over other tastes.
Why do people tend to prefer sweet foods? Here are non-genetic factors that cause an excessive preference for sweet foods.
Sweet foods are addictive - Sweet foods activate the same receptors in the brain that drugs like heroin do. This makes them addictive and increases people’s tendencies to prefer sweet foods over other types.
Sweet foods are associated with having a good time - Think of times you indulged in sweet foods - weddings, parties, and get-togethers with friends. Sweet beverages and desserts are associated with happiness and hence are more preferred.
Sweet foods are comforting - Sweet foods are known for their comforting and soothing properties. The mood-altering nature of these foods makes them a preferred choice.
Habit - There was a time when sweet foods were only available occasionally. Right now, though, the common American diet is sugary and sweet. Our bodies are used to all the excess sweetness we consume, and this has become a habit.
Age - Children have a higher tendency to prefer sweet foods. This could be because of their higher growth rate. Since children grow faster, their bodies look forward to high-energy food sources. Sweet foods are high in calories and give instant energy.
When you consume more than the recommended values of sugar a day, here is what will happen.
-Excess caloric intake leading to weight gain
-Increased risks of pre-diabetes and diabetes
-Psychological disorders including depression and anxiety
-Increased risks of heart diseases
-Increased risk of Non-Alcoholic Steatohepatitis (NASH) and Non-Alcoholic Fatty Liver Disease (NAFLD)
-Sugar craving and sugar addiction
Sugar addiction increases your tendency to prefer sweet foods and makes your body crave sugar all the time. This is similar to mild drug addiction. Stopping sweet foods all of a sudden can lead to the below withdrawal symptoms.
-Anxiety and depression
-Insomnia or an excessive need to sleep
-Difficulty in focusing
Pick natural sugars over processed sugars - You could have a higher tendency to prefer sweet foods. However, get your source of sugar from natural sources like fruits and vegetables. These are healthier and also give you other essential vitamins and minerals needed for the body.
Check nutritional labels - Before you pick up something from the grocery store, check the nutritional label. Satisfy your sweet tooth with low-sugar or natural sugar versions. Stay away from foods and beverages that are loaded with refined sugar. These only make you more addicted to sweet foods.
Know your genetic makeup - A simple genetic test will show you if you have a higher tendency to prefer sweet foods. If so, start making healthier sugar choices and slowly bring down your processed sugar intake to get healthier.
Switch to a low-calorie sweetener - Low-calorie sweeteners are also called artificial sweeteners. If you have existing health conditions that can be made worse with sugar intake, then use artificial sweeteners sparingly to handle your cravings.
Burn the calories - Craving for a donut? Indulge in one and then work out for an extra 15 minutes to match up the sugar you consumed.
Overeating is a common problem with adults and children across the world. Overeating is a recognized disorder, and about 28.8 million Americans face this at least once in their lifetimes.
While taste and love for food can cause people to overeat, genetics can also increase a person’s tendency to overeat.
Eating is a daily activity needed for the survival of all living beings. Food gives energy and helps human beings grow. The amount of food you eat has to depend on the calories you burn. In simple terms, the more active you are and the more energy you burn, the more food you will need to eat.
Overeating happens when you consume more calories than you can burn. Let’s say it is Thanksgiving, and you have been gorging on roast turkeys, candied yam, sweets, and drinks all day long.
This is a typical day of overeating for you. Most Americans overeat during festivals and holidays. For some individuals, overeating is an everyday problem.
Overeating can be a symptom of bulimia nervosa (overeating followed by vomiting out the contents) or binge eating (overeating frequently).
The tendency to overeat is one of the biggest mental health challenges in the country.
While excessive hunger is one reason people overeat, other genetic and non-genetic reasons increase a person’s tendency to overeat. We will be discussing these in detail in the coming sections.
Knowing these reasons and working on them will help you handle the condition better.
Human beings are designed to handle a specific amount of food. The stomach expands to handle large amounts of food when you overeat. The expansion puts pressure on the stomach and the nearby organs in the body.
After you eat, food is broken down by saliva and other enzymes. Fat, proteins, and sugar are separated. The sugars enter the bloodstream and are passed on to the cells for energy. Excess sugar is stored as glycogen in the liver and muscles.
Proteins are broken down into amino acids and are used by the tissues and muscles. Excess proteins are converted into fats and sugars.
The body uses a certain amount of fats needed, and the remaining goes to the adipose tissues and are stored.
When you overeat and have excess proteins and sugars in the body, both get converted into fats. Fats end up getting stored in the fat cells, and this leads to gradual weight gain.
When you receive excess calories through food, your fat cells keep building up. This leads to weight gain, obesity, and other lifestyle conditions.
Your brain takes about 20 minutes to let your stomach know that you are full. Most people end up overeating in these 20 minutes.
When you consume more calories than what’s needed for the body, it is considered overeating. When you know your Basal Metabolic Rate (BMR), it is easy to calculate the calories you can safely consume in a day.
Here is how you can calculate your BMR.
Women: BMR = 655 + (4.35 x weight (pounds)) + (4.7 x height (inches)) - (4.7 x age in years)
Men: BMR = 66 + (6.23 x weight (pounds)) + (12.7 x height (inches)) - (6.8 x age in years)
Let’s take an example. A 30-year-old woman weighs 154 pounds. She is 62 inches tall. Here is her BMR value.
655+ (4.35X154)+(4.7X62)-(4.7X30) = 1475
Converting BMR to recommended calorie consumption.
The FTO gene is one of the most discussed genes for weight gain and the tendency to overeat. Many studies mention that this gene is a switch that controls many other ‘weight-related’ mechanisms in the body.
The rs9939609 SNP of the FTO gene increases a person’s tendency to overeat. The ‘A’ allele of this SNP causes the below effects in the body.
-Increased Ghrelin levels : Ghrelin is called the hunger hormone. Increased ghrelin means increased hunger
-Increased food intake
-Decreased satiety levels : individuals don’t feel contended after eating food
-Increased risks of emotional and binge eating
People with the AA genotype have a higher tendency to overeat and also are at a higher risk for developing weight gain-related side effects like obesity, heart conditions, diabetes, and risks for cancer.
About 14% of the population have the AA genotype. Those with the AT genotype make relatively healthier food choices. They are satisfied after eating their meals and do not overeat.
Why do people overeat? The different non-genetic factors that push people to have an increased tendency to overeat will surprise you.
Boredom - People eat when they are bored. This is a very common reason why healthy individuals gain weight. Finding other ways to deal with boredom can prevent the tendency to overeat.
Mental stress and anxiety - A person’s mood affects how much the person eats. Both positive and negative moods can cause people to overeat. A study concluded that women who were stressed at work overate at lunchtime!
External cues * - External cues play a very important role in causing people to overeat. In a country like America, food is everywhere. You are constantly exposed to food and beverages either sold or advertised, forcing people to eat more than what they need.
*Social pressure - Eating has become a social habit. People invariably visit restaurants and bars when they get together. Those who have an active social life end up eating more over the week.
Lowered ability to resist - Some people have a better ability to resist overeating than others. While one person can stop with two slices of pizza, another person ends up stuffing 3-4 pieces and then feeling uncomfortable. This is another cause for overeating.
Taste - Food has become so much tastier now. International tastes and flavors are available, encouraging people to eat more and eat often.
Overeating may not look like a problem at all until you experience one or more of the below symptoms.
-Discomfort after you finish your meals
-Breathing difficulties because the stomach pushes the lungs
-Gas and bloating
-Feeling of tiredness and sluggishness after a meal
-Not able to stay physically active after a large meal
-Guilt and shame of overeating
-Nausea and vomiting
-Increased metabolism leading to sweating and dizziness
Here are some of the long and short-term side effects of overeating.
-Weight gain and obesity
-Sleep apnea (breathing stopping and starting randomly at night)
-Increased risks of type II diabetes, high blood pressure, and heart diseases)
-Increased risks of different types of cancer
-Impaired brain functioning in older individuals
Know why you are overeating - Knowing the reason behind overeating can help address the problem better. If you are genetically prone to overeating, making lifestyle changes like counting calories and taking professional help. If one particular reason like stress or boredom makes you overeat, handle that first.
Know your trigger - Certain foods can trigger overeating. It could be a particular taste, flavor, or even a place that makes you overeat. Know your trigger, and stay away from it.
Do not eat directly from containers - If you want to eat chips, add a handful to a plate, replace the pack of chips in a closed shelf, and then start eating. If you eat directly from the pack, you will not stop until you finish the whole pack.
Choose healthier food options - Eating the same quantity of fruits and chocolates does different things to your body. Fruits are not addictive, while chocolates are. Pick the right foods, and you will not have the urge to overeat.
Stop before you feel full - One trick that experts suggest to prevent the tendency to overeat is to stop before you feel full. This way, you can consciously prevent overloading on food.
Manage boredom and stress differently - If you are bored, stressed, or anxious, find other healthier ways to manage them without depending on foods.
Take help - Is overeating causing mental, physical, and social issues? Take professional help to handle the disorder.
One of the major challenges faced by obese people in terms of weight loss and management is the prevention of weight regain after successful weight loss. Some studies suggest that 80% to 95% of people who lose weight regain it shortly after.
While many people face success with weight loss, long-term maintenance of weight loss has often been an elusive goal.
Energy expenditure varies according to changes in body weight. Higher body weight is associated with higher energy expenditure. Weight loss is accompanied by a decrease in resting energy expenditure (REE) (energy needed to fuel minimal daily functions of cells and organs). The reduction in REE can lead to weight gain. Yes, it is a pretty vicious cycle!
The composition of the diet used for weight loss also influences REE and weight gain. According to a study, low-carb, high-protein diets are effective for short-term weight loss, while its effects on long-term weight loss are still hazy.
According to The Prevention of Obesity Using Novel Dietary Strategies (POUNDS LOST) study, REE decreased the least in the very low carbohydrate group, suggesting that a low-carbohydrate diet may discourage weight regain.
Another study found that the high-protein, low-glycemic index diet was best for maintaining weight loss.
A meal replacement is a drink, bar, soup, etc., intended as a substitute for a solid food meal, usually with controlled quantities of calories and nutrients. With most branded meal replacements, two of your usual meals are substituted with a meal replacement.
In the early days, the meal replacement diet was very low in calories - around 200-400 kcal a day - compared to the average calorie consumption by an American (2400 kcal). Such low-calorie diets lead to muscle breakdown, slowing down your metabolism. Further, most of these diets are nutritionally deficient. All of these contribute to easy and quick weight regain.
However, these days, the meal replacement diets have become more nutritionally sound, including the appropriate amounts of macronutrients and micronutrients. They are also not as low in calories - nowadays, meal replacement diets have a calorie content of 800–1000 kcal per day. This is sufficient enough to prevent/slow down muscle breakdown. Meal replacements are also used along with the usual diet getting the calorie count up to 1200 per day.
This gene is involved in controlling fat metabolism (break down) and insulin sensitivity (how well your body responds to insulin) in the body.
ADIPOQ gene codes for a protein called the adiponectin, which is involved in aids fatty acid breakdown. Higher the adiponectin levels, the more efficient the fatty acid breakdown.
Decreased adiponectin levels are thought to play a central role in obesity, and type 2 diabetes.
rs17300539 of ADIPOQ Gene and Weight Gain Tendency
The SNP rs17300539 is also annotated as -11391 G/A. In a study, 180 Spanish volunteers were put on a low-calorie diet. An 8-week follow-up revealed that people who have the A allele had a protective effect against weight regain. On the other hand, people with the GG type experience weight regain.
A allele carriers also had higher adiponectin levels.
The PPARG gene encodes the peroxisome proliferator-activated receptor, a nuclear receptor found mainly in the adipose tissue, macrophages, and colon. PPARG is associated with fatty acid storage and glucose metabolism. PPARG also increases insulin sensitivity by enhancing the storage of fatty acids in fat cells. Certain mutations in this gene influence the weight regain tendency in individuals.
rs1801282 of PPARG Gene and Weight Gain Tendency
The minor G allele is associated with lower PPAR gamma activity. This decreases insulin sensitivity. People with the G variant were shown to be associated with a higher weight regain tendency.
Other genes influencing weight regain tendency include BDNF and TFAP2B.
Other common factors that influence weight regain are:
The more weight you lose, the fewer calories your body needs to maintain itself. Say you go on a 1500-calorie diet. You may see some significant weight loss initially. But as your calorie demands reduce, continuing the same calorie consumption may lead to weight regain. So it’s important to recalculate your calorie requirements as and when you experience weight loss.
With some diets, like crash diets or other calorie-deficit diets, your body is forced to break down muscle to use for energy - lower the muscle mass, slower the metabolism. When your metabolism slows down, it becomes a lot easier to regain those lost pounds.
Yo-yo dieting, the colloquial term for weight cycling, describes the cyclic pattern of losing weight, regaining the lost weight, and dieting to lose that weight again. Since the weight goes up and down like a ‘yo-yo,’ the term yo-yo dieting came up. This kind of fluctuation of weight has been linked to conditions like obesity and type 2 diabetes.
A review of 19 studies that examined the effects of the weight cycle revealed that in more than half the studies, there was an association between weight cycling and increased body weight and risk of obesity.
Weight loss leads to both fat and muscle loss. While fats are regained easily, the same doesn’t happen with muscles. Thus with weight cycling, muscle mass decreases over time.
Leptin is a hormone released by fat cells. It is a satiety hormone that signals your mind that you are full - controls your appetite. When you lose weight, you lose fat cells - this results in a decrease in your leptin hormone levels. That makes you hungry. Once you come off the diet, you’ll be left with an oversized appetite.
According to a study in The New England Journal of Medicine, people with the greatest swings in weight also had a 78% increased risk of diabetes, even after correcting all traditional risk factors. This is because weight fluctuations also result in changes in insulin levels.
A study states that weight gain is more dangerous than being overweight for heart diseases. Weight cycling has been studied to narrow down the blood vessels in the heart, leading to coronary heart disease.
Weight cycling, or losing and regaining weight repeatedly, may also lead to gallstones. The more weight you lose and regain during a cycle, the greater your chances of developing gallstones. According to a study published in the Archives of Internal Medicine, men whose weight fluctuated more than five pounds were more likely to develop gallstones.
Gut bacteria are the good bacteria that help you digest food and are crucial to prevent digestive disorders. Yo-yo dieting can mess up this bacterial population in your gut. This can affect your digestive health, and in some cases, mental health too!
Increasing muscle mass gives a boost to your metabolism. Exercising your muscles can also prevent muscle loss while dieting.
Protein brings about the feeling of fullness and reduces appetite. It also regulates hunger and satiety hormones. Protein metabolism requires a great deal of energy. Therefore, increasing the protein content in your diet may result in burning more calories.
The thyroid gland regulates your metabolism. Many studies have shown that treatments with excess thyroid hormones can result in weight loss - however, when the hormone levels drop to the original levels, the weight is regained.
Low thyroid levels (hypothyroidism) can result in weight gain. So, it is important to keep your thyroid hormone levels in check.
Drinking a glass of water before meals can promote fullness and thus, reduce your calorie intake. Further, drinking adequate amounts of water also helps burn calories throughout the day.
Sleep disturbances, especially deprivation, can result in weight gain in adults. It can also interfere with weight maintenance in people who have lost weight. Poor sleeping habits have been linked to lower levels of leptin - an appetite-controlling hormone.
Weight gain is an increase in body weight which can occur due to increase in muscle mass, fatty acids accumulation or even buildup of excess water.
Weight gain has been linked to many health conditions like obesity, diabetes, heart disease, and hypothyroidism.
According to the WHO, world wide obesity has tripled since 1975, and around 39% of the adults in the world are overweight.
A person is considered overweight if the Body Mass Index (BMI) is greater than 25.
There are two globally seen reasons for weight gain:
1. You consume more energy (calories) than you expend
2. A sedentary lifestyle with very little to no physical activities
Other leading causes for weight regain include:
Foods that are sugar and fat-filled tend to stimulate the reward center in your brain (regions in the brain that give rise to feelings of pleasure and reward). Prolonged junk food consumption can thus cause addiction. Food addiction is often compared with addiction to alcohol and drugs.
Insulin regulates blood sugar levels by moving the sugar into cells. It also promotes fat storage in the body. Insulin resistance leads to increased production of insulin. This leads to increased hunger and appetite.
Leptin is a satiety hormone that reduces appetite. With leptin resistance, the hormone fails to signal to the brain how high the fat storage is in your body. This is one of the main causes of obesity in adults.
Muscles are an efficient calorie burner. As you age, your muscle mass decreases, and as a result, you tend to burn fewer calories. If the diet is not adjusted accordingly, it may result in weight gain.
Steroids are usually used to treat conditions like arthritis and asthma. Steroids affect your metabolism and the way your body stores fats. It also increases your appetite leading to weight gain, especially in the abdominal area.
Different people respond in different ways to stress - while for some people, stress may result in weight loss, in most others, it leads to weight gain. When the stress hormone cortisol levels increase, your appetite also increases, which can lead to overeating and weight gain.
In the evolutionary history of humankind, body fat seems to have been nature’s way of storing its own food reserves. During the times of famine, people who had these “thrifty” genes that could store the greatest amount of food as fat had a better survival advantage than the others. In fact, this ability to produce more fat from less food intake may have been the difference between life and death for the species.
Fast-forwarding to this era of surplus food availability, these genes are no longer “advantageous.” In fact, it is those very same genes that have been implicated in obesity and weight gain. The easy availability of high-calorie foods and reduced physical activities seem to be the two main players that account for obesity.
More than 400 genes have been studied in association with overweight and obesity - however, only a few of them have shown a strong influence on weight gain. These genes play a role in:
- How your body stores and burns off the fat
- Your appetite
- The levels of hunger and satiety hormones
- How your body responds to stress.
The influence that genes exert over all these variables differ from person to person. Knowing the extent to which your genes influence weight gain can come in handy for weight management and weight loss measures.
FTO gene is located in chromosome 16 and encodes the enzyme alpha-ketoglutarate dependent dioxygenase FTO. FTO gene is highly active in the hypothalamus region of your brain, which controls appetite. This was the first gene to be linked to obesity. Even though the association was observed only in Europeans at first, many studies since then have confirmed the same effect on other populations. Even now, many scientists suggest that the FTO gene has the largest known effect on body weight.
rs9939609 of FTO Gene and Tendency to Gain Weight
rs9939609 is a well-researched SNP in the FTO gene. The A allele in this gene is associated with an increased expression of the FTO gene. People with the AA and AG types have an increased appetite and tend to gain more weight than those with the GG type.
Several other genes, like BDNF, LEP, ADIPOQ, ADRB1, UCP, PCSK, etc., also influence your tendency to gain weight.
An underactive thyroid leads to a decreased production of thyroid hormones - a condition known as hypothyroidism. This results in slowed-down metabolism, which may contribute to weight gain.
Cushing syndrome is a condition characterized by increased production of the cortisol hormone. Elevated levels of cortisol interfere with your metabolism and may put you at risk for weight gain. It also results in deposits of fatty tissues at the midsection, face, and lower back.
Insomnia is another condition that results in elevated levels of cortisol as well as another hormone, insulin. These hormones can interfere with the secretion of hunger and satiety hormones, making you crave sugary and fatty foods.
This condition is commonly observed in women of early reproductive ages. PCOS occurs due to a buildup of the male hormone, androgen. Elevated androgen levels lead to insensitivity to insulin. As a result, blood sugar builds up, leading to weight gain.
Congestive heart failure occurs when your heart cannot pump out enough blood to meet your body’s needs. As a result, blood and other fluids can build up in your ankles and feet, resulting in swelling and rapid weight gain.
Your calorie requirement is based on your gender, body weight, age, and level of physical activity. After you calculate your calorie needs, estimate your calorie intake, and match them to your needs. If you are looking to lose weight, consume fewer calories.
Cane sugar is essentially sucrose, which is harmful to the body when consumed in higher quantities. This type of sugar is often added to sweets and foods and can cause weight gain.
Muscle building powers up your metabolism and minimizes naturally occurring muscle loss. This way, if you choose your calories wisely, you can consume more of them without the threat of gaining weight.
Stress, as we know by now, leads to weight gain. People who are stressed out tend to overeat and go for high-calorie comfort foods. Stress can be identified with some warning signs like irritability, anxiety, and muscle tension. Meditation, a healthy sleep cycle, yoga, and mindful eating are excellent ways to combat unwanted stress.
Eggs have been a part of our diet for thousands of years now. Being high in protein and several vitamins, eggs are rated as one of the most nutritious foods on the planet. However, new research from the University of South Australia shows that excess egg consumption can increase your risk of diabetes.
Diabetes mellitus, commonly known as diabetes, results in high blood sugar. The insulin hormone is responsible for regulating blood sugar levels. With diabetes, your body either doesn’t make enough insulin or can’t effectively use the insulin made.
In the United States, 27.9 and 32.7 percent of the population have diagnosed and undiagnosed diabetes, respectively.
Untreated diabetes can increase the risk of dangerous complications, including stroke and heart disease.
According to The American Diabetes Association, eggs are a good choice for people with diabetes - primarily because one large egg contains only around 0.5 g of carbohydrates. However, eggs are high in cholesterol - one large egg contains nearly 200 mg of cholesterol.
If you have diabetes, it is recommended to limit your egg consumption or consume only the whites.
The University of Australia, along with the China Medical University and Qatar University, assessed egg consumption in a large sample of Chinese adults. They found that “people who regularly consumed one or more eggs per day (equivalent to 50 grams) increased their risk of diabetes by 60 percent.”
The prevalence of diabetes in China has now crossed the global average of 8.5%. According to the study, China has experienced a nutritional shift, with many people moving from a plant-based diet to processed diets that include meat and other animal-based foods over the last few years.
Egg consumption has also been steadily increasing. From 1991-2009 the number of people consuming eggs in China has nearly doubled.
The effect of egg consumption on glucose was determined by measuring the fasting blood glucose levels. The researchers discovered that “higher long-term egg consumption (greater than 38 grams per day) increased the risk of diabetes among Chinese adults by approximately 25 percent.”
Additionally, people who consumed more than 50 grams of egg had a 60% increased risk for diabetes. This effect was more pronounced in women than men.
Shorter and lower-heat cooking methods help retain most of the egg’s nutrients.
So, boiled or poached eggs without added salt are healthier than frying them in butter or unhealthy oil.
The egg whites are high in protein and low in cholesterol.
Your diet can help both managing and preventing diabetes. Some diabetic-friendly foods include:
Vitamin D is a fat-soluble vitamin required by all living beings for bone health, calcium absorption, and brain function. This vitamin is also known as calciferol.
Most of the vitamin D is obtained naturally from sunlight. While melanin (the skin pigment) protects the skin from the harmful effects of ultraviolet rays, excess melanin can also hinder the absorption of vitamin D from the sunlight.
According to a study published in the Journal of Nutrition, healthy vitamin D levels in mother during pregnancy can positively affect the child’s IQ (Intelligent Quotient). The higher the vitamin D levels, the greater the IQ scores during childhood.
The sunlight consists of two kinds of UV-rays - UVA, and UVB. UVA doesn’t have much of a biological role. Only UVB helps in the synthesis of vitamin D in the skin.
Melanin has photoprotective action - It protects the skin from the harmful effect of ultraviolet radiation. However, higher melanin levels can lead to lower production of vitamin D3.
Darker skin tone is associated with higher levels of melanin.
For light-skinned people, an exposure time from 20-30 min, for two-three times a week, is enough to produce around 20,000 IU of vitamin D3, while for dark-skinned people, the exposure time needs to increase by 2-10 fold to get the same level of vitamin D3.
The baby in-utero (in the womb) receives its vitamin D supply for brain development from the pregnant mother.
The melanin production is higher in black women - so there are a higher number of cases of vitamin D deficiency among them.
According to the study, 80% of black pregnant women in the U.S. may have vitamin D deficiency.
Among the study participants, approximately 46% of the mothers were deficient in vitamin D during their pregnancy, and vitamin D levels were lower among black women compared to white women.
After controlling several other factors that influence IQ, a study examined the relationship between vitamin D levels in pregnant women and IQ in children.
It was observed that higher vitamin D levels in pregnancy were associated with higher IQ in children ages 4 to 6 years old.
The recommended daily intake of vitamin D is 600 international units (IU). However, on average, Americans consume less than 200 IU in their diet.
In most cases, vitamin D deficiency has an easy fix. Even if it is difficult to get enough sun exposure, vitamin D supplementation is an effective alternative to meet your requirements.
Alcohol has become a part of people’s lives. People drink when they are happy, excited, sad, or stressed out. It is one of the oldest recreational drugs in use. While many people can handle their drink well, some have extremely unpleasant symptoms when they consume even limited quantities of alcohol.
Alcohol Flush Reaction (AFR) is a condition that causes red patches on the skin after consuming alcohol. These red patches are mostly seen on the cheeks, neck, and shoulders. Sometimes, they can also be seen all over the body.
If you have East Asian friends and go out for drinks with them, you may have noticed their faces turning red after just a couple of sips of their drinks.
About 30-50% of East Asians, including Koreans, Chinese, and Japanese experience alcohol flush regularly.
According to 100 different studies, moderate consumption of alcohol may reduce the risk of cardiovascular diseases by up to 40%.
The right levels of alcohol consumption also increases healthy High-Density Lipoprotein (HDL) levels in the body
Moderate drinkers may be at a lower risk of developing type II diabetes than non-drinkers.
However, when you consume more than four drinks a day, the risks of alcohol consumption may outweigh the benefits.
Genetically, some people can handle their alcohol better and benefit from moderate drinking. For others, even small quantities of alcohol only cause increased health risks. We will discuss this in the later sections.
Scientists believe that the alcohol flush reaction has its roots in China about 10,000 years ago. This was the same time that agriculture became a staple form of livelihood here and people’s diet changed. Rice became a common food choice.
According to the experts, the change in diet and lifestyle caused changes in the gene makeup of the Chinese population.
Alcohol flush reaction is a result of such a random change in the genes (gene mutation). It spread from here to neighboring parts of the country and is now very common with East Asians.
It is very rare for non East-Asians to carry this variant (type) of gene.
When you consume alcohol, 90% of its processing happens in the liver. An enzyme called alcohol dehydrogenase converts ethanol into ethanal (acetaldehyde).
Acetaldehyde is a toxic by-product. Another enzyme called aldehyde dehydrogenase quickly converts this by-product into ethanoate (acetate).
Before the liver starts processing alcohol (in about 20 minutes after consumption), alcohol is absorbed from the stomach to the bloodstream and reaches the whole body, including the brain.
Some people experience alcohol flush and others don’t because of their genes.
In people with alcohol flush, the body does not produce enough aldehyde dehydrogenase to convert acetaldehyde to acetate. This causes excess accumulation of the toxic acetaldehyde in the body. This leads to the symptoms of alcohol flush including skin blotching, nausea and general feeling of discomfort.
Alcohol reaches your brain within minutes after you have had your drink.
Your Central Nervous System (CNS) helps with processes like thinking, reasoning, understanding, and motor functions. Alcohol slows down the CNS processes. People experience a foggy mind, inability to remember things, slowed motor functions, and dull hearing after they start drinking because the alcohol affects the nerve cells and makes them slow.
How fast alcohol affects your brain’s activity can depend on factors like what other drugs you have had before, your age, size, and gender and also your genes.
If you are a woman, then you are at a higher risk for developing alcohol-related disorders than a man! It sounds unfair but this is true.
Drinking the same amount of alcohol as a man seems to damage the woman’s health more than it does a man’s.
When it comes to alcohol disorder-based deaths, women have 50-100% more mortality rate than men.
Women have lesser water content in their body than men. So, the concentration of alcohol in the body of a woman is higher and they get intoxicated faster.
Because of the presence of estrogen, more women experience liver damage because of excess alcohol consumption than men.
The U.S. Dietary Guidelines for Americans suggest the below recommended values for moderate alcohol consumption.
Adult men - 2 drinks a day
Adult women - 1 drink a day
The recommended values are for normal adults without alcohol flush or alcohol abuse conditions.
People with alcohol flush reactions will have to limit their alcohol consumption based on how intense their symptoms are.
The Body Alcohol Content (BAC) is a measure of how much alcohol has reached your Central Nervous System (CNS). BAC is measured in terms of percentage of alcohol in 100 ml of blood. Below are the values of BAC and their corresponding symptoms.
Alcohol flush is one of the earliest symptoms of alcohol consumption.
Here are the symptoms of alcohol flushing:
Alcohol is a drug and depending on the tolerance levels and the years of alcohol use, symptoms of alcohol withdrawal may include:
People with alcohol flush reaction are not usually prone to overusing the drug as the side effects discourage them from drinking more.
Genetics play an important role in determining whether or not your body can handle alcohol.
The ALDH2 gene helps produce aldehyde dehydrogenase (ALDH) that converts the toxic acetaldehyde from alcohol into acetate. This step is very important to prevent acetaldehyde accumulation in the body that leads to alcohol flush.
Alcohol flush reaction is a condition that causes red patches in the skin, nausea, and general discomfort after a person drinks. This condition is very common in people with East Asian ancestry. As the person continues to drink, the symptoms get worse. Genetics play a very important role in causing alcohol flush reactions. Knowing your limit, choosing alcohol with lowered ABV and keeping the stomach full and the body hydrated all help bring down the intensity of the condition. Certain medications can help too.
Do you start your day with a cup of freshly brewed coffee? Does a cup of tea warm your insides and leave you feeling fresh in the evening? Do you stock up energy drinks in your fridge to help handle late nights?
All these beverages have one thing in common - caffeine.
Caffeine is an organic compound found in plant sources. Caffeine is a legally accepted and consumed psychoactive drug ( a chemical that alters nervous system functions). Caffeine alters a person’s mood, behavior, and energy levels.
While some studies have praised the beneficial effects of caffeine on human health, others warn about the health risks. Why does the same substance lead to different health outcomes?
The answer to these questions is not only applicable to caffeine but also to a lot of other substances.
We are all genetically unique. While some substances produce relatively similar effects on our bodies- many substances, including caffeine, are processed differently in different individuals.
When a drug fails a clinical trial- it does not mean that every individual who took that drug failed to respond. On the other hand, there is no approved drug that works equally well on every individual.
It is common knowledge that some drugs work really well for some, but not for others. We need higher doses of certain drugs and lower doses of others. There is a dose difference for certain drugs for men, women and children.
Caffeine is no different. Unless the genetics and other factors are accounted for, it will not be easy to say whether caffeine is good or bad for you. Keep reading to find out the unique genetic aspects of caffeine metabolism (processing in the body)
There are about 60 species of plants that can produce caffeine. Few top sources are:
Did you know that about 85% of Americans consume at least one caffeinated drink a day? Coffee remains the most consumed caffeinated drink among adults.
How much caffeine is too much? Do you have to give up on caffeine to lead a healthy lifestyle? Keep reading to know more.
The history of caffeine is closely associated with the histories of its plant sources.
It was 2437 BCE. The Chinese Emperor Shen Nung was relaxing in his garden. The wind blew a couple of leaves into his cup of boiling water. He noticed that the water changed color and smelled fragrant. The leaves were later identified to be from the tea shrubs. Tea leaves are considered a stimulant (a drink to energize the body).
There are many stories on the discovery of caffeine. Some scripts say the ethnic Oromo people of Ethiopia recognized coffee beans to have energizing properties.
The more popular version is of Kaldi, an Ethiopian goat herder. He noticed his goats getting all excited after consuming coffee beans. He mentioned this in a monastery and the first cup of coffee was brewed there.
The leaves of the yaupon holly tree were brewed as early as 8000 and 1000 BC. This was then known as the black drink.
In many West African cultures, it is still a regular practice to chew on kola nuts when people feel tired.
Caffeine is very easily absorbed by the body. 99% of caffeine is absorbed in about 45 minutes.
Once you consume a caffeinated beverage, it enters the gastrointestinal tract. Caffeine is processed in the liver by an enzyme that breaks it apart into different chemicals like paraxanthine, theobromine, and theophylline.
Peak levels of caffeine are observed in the plasma between 15 minutes and 120 minutes after oral consumption.
Caffeine easily reaches the brain. Adenosine is a chemical in the brain that induces sleep. The structure of caffeine is similar to that of adenosine. Caffeine attaches itself to the adenosine receptors (a protein that responds to adenosine) and prevents people from feeling sleepy.
The more caffeinated beverages you drink, the more adenosine receptors your body will produce.
Over time, you will need more amounts of caffeine to keep you awake.
Plant sources are not the only way to get your dose of caffeine. Caffeine is artificially synthesized in industries too.
The production of caffeine in industries began during World War II. Germans were unable to obtain caffeine because of various trading bans. They hence had to create caffeine artificially.
Today, synthetic caffeine is very cheap and tastes just like natural caffeine. It would not be surprising if you cannot tell the difference between the two.
While synthetic caffeine is safe when had in small amounts, the problem is with the manufacturing process. Ammonia goes through a lot of steps and chemical interactions to turn into caffeine.
The synthetic caffeine industry is also unregulated in most countries. All this makes synthetic caffeine a slightly worrying product in the market.
Caffeine is addictive. Your body goes through withdrawal symptoms when you try to reduce your caffeine intake. Few popularly noticed symptoms of caffeine withdrawal are:
Withdrawal symptoms can start 24 hours after giving up caffeine and can last for up to 9 days.
Caffeine sensitivity refers to having an adverse reaction to consuming caffeine. For most people, consuming more than 400 mg of caffeine can cause physical and mental discomforts.
Few others can be hypersensitive to caffeine and cannot tolerate it even in small quantities. Here are some non-genetic factors causing caffeine sensitivity.
How are some people able to process caffeine better than others? Genetics is the answer.
CYP1A2 gene - The CYP1A2 gene influences how fast caffeine is processed in your body and how you react to it. One particular SNP that can increase or decrease the effects of caffeine consumption is the rs762551.
AC and CC genotype
ADORA2A gene - The ADORA2A gene produces the adenosine receptors in the brain. You know by now that caffeine attaches itself to the adenosine receptors and prevents the person from feeling tired or sleepy.
The ADORA2A gene is also responsible for increasing dopamine levels (the happy hormone). Variations in the ADORA2A gene are said to cause mood swings, anxiety, and irritation.
Caffeine is a legally consumed drug that can alter the mood and increase attention and focus. It is naturally present in up to 60 plant sources. It is also artificially produced in industries. Normal adults have to limit their caffeine intake by up to 400 mg. Caffeine overdose can lead to mood disorders, rapid heartbeats, and high blood pressure. Caffeine withdrawal has to be handled gently and causes symptoms like depression, anxiety, and low energy levels. Genetically, some people can show high caffeine sensitivity and need to monitor their caffeine consumption.