There are very few macronutrients discussed as extensively as protein. Protein is an essential nutrient that helps support all aspects of the human body. Proteins (Amino acids) are the building blocks of the human body. Proteins are made of chains of amino acids linked by a chemical bond. Amino acids are organic molecules that majorly contain carbon, oxygen, hydrogen, and nitrogen. In nature, there are about 500+ amino acids available. Out of these, nine are considered essential amino acids that the human body cannot produce. These have to be obtained from the foods you eat.
Nine Essential Amino Acids
Sources Of Proteins
Proteins are abundantly found in all plant and animal sources. About 70% of protein intake in North America is through animal-derived foods. Over the world, about 60% of protein sources are plant-based foods.
Proteins At The Molecular Level - Getting Technical
Once you eat protein-rich foods, proteins reach your stomach. The hydrochloric acid in the stomach along with an enzyme called proteases help in breaking down proteins into smaller molecules. The amino acid sequence in proteins is connected together by peptides. Proteases help break these peptides. The smaller chains of amino acids now move to your small intestine. Here, enzymes like trypsin, carboxypeptidase, and chymotrypsin help break down the smaller chains into individual amino acids. The broken down amino acids are absorbed in the small intestine and reach the bloodstream. They are taken from here to all the cells in the body. When you consume a variety of protein-rich foods throughout the day, your body can collect the essential ones from different sources and get what’s needed for its survival.
Protein Functions In The Body
Proteins are abundantly needed and present in the body. It is essential for many vital processes including
Chemical reactions - As enzymes, proteins carry out thousands of chemical reactions in the body. Without enzymes, the body will come to a standstill.
Transmitting signals - Proteins act as messengers and help transmit signals and information between different cells, tissues, and organs. Proteins also help transport smaller molecules between different cells.
Providing structure - Proteins support the healthy growth of cells and give structure to the muscles and tissues. Proteins are also the basic building blocks of all the organs in the body.
Building immunity - Antibodies are types of proteins produced in the immune system. These help fight against harmful microorganisms attacking the body.
Proteins And Weight Loss
One of the most discussed functions of proteins is aiding weight loss. There are several protein-based diet plans on the internet that promise quick and rapid weight loss with minimal effort.
Do all these diet plans work? No. However, proteins help people lose weight when consumed the right way. Proteins help in increasing metabolism and reducing appetite. Both factors are beneficial to lose weight healthily. Particular gene types also encourage weight loss in certain individuals when they consume a protein-rich diet.
Did You Know?
Proteins are one of the most essential nutrients needed. There are so many functions that depend on protein sources in the body.
In simple terms, when you do not consume proteins, you cannot survive.
Protein turnover is a wonderful way your body keeps maintaining the levels of essential proteins in the body.
When you are asleep, your body does not get its source of proteins from food for 6-8 hours at a stretch. In this time, your body breaks down its own stored proteins and obtains essential amino acids. These stored proteins come from both skeletal muscles and your skin.
When you fast for days together, the body starts using up proteins from your muscles too. Every day that you fast, you will lose 32 grams of muscle because of protein turnover.
The History Behind Proteins
Did you know that the first living molecule that originated on earth was a kind of protein?
How fascinating is that!
That’s how important proteins are for living organisms.
Protein was first discovered by Gerhardus Johannes Mulder in the year 1837. He initially assumed that proteins were made of just one type of large molecule.
A Swedish chemist named Jöns Jacob Berzelius is given credit for naming protein in 1838. Protein means ‘primary’ in Greek.
The main problem with studying proteins was the difficulty in purifying them in large quantities. The only types of proteins that were studied extensively were those that were easily available from egg whites, blood collected from slaughterhouses, and digestive enzymes.
In 1949, insulin was the first protein for which the amino acid sequencing was done successfully. It was then that scientists understood proteins contained linear polymers of amino acids.
Since then, protein has been extensively researched and analyzed and its importance has only grown.
RDA of Proteins
The recommended intake of proteins is set as 0.36 grams of proteins per pound of body weight. In case you are an active person or an athlete, you may need up to 0.60 grams of proteins per pound to match up your physical demand.
This is the minimum recommendation to prevent a person from getting protein deficient.
How Genes Influence Protein Intake and Weight Loss Tendency?
TCF7L2 Gene and Protein Metabolism
This gene produces a protein that plays an important role in several functions in the body. Changes in the TCF7L2 gene affect the relationship between a high-protein diet and weight loss.
rs7903146 and rs10885406 of TCF7L2 Gene and Weight Loss Tendency On Protein Intake
In both the rs7903146 and rs10885406 SNPs, the C and A alleles respectively help individuals get the most out of a high-protein diet. Individuals with these alleles do not gain weight upon protein intake.
TFAP2B Gene and Protein Metabolism
The TFAP2B gene helps produce the AP-2B transcription factor. This controls the activities of other genes around and a particular SNP is known to affect the relationship between weight gain and protein intake.
rs987237 of TFAP2B Gene and Weight Loss Tendency On Protein Intake
The A allele of this SNP has very low risks of obesity. However, the G allele individuals are at high risk for obesity. In both variants, a high protein diet will help maintain existing weight and prevent further weight gain.
Non-genetic Factors Relating To Saturated Fats And Weight Gain
Higher caloric intake - Saturated fats have 9 calories per gram of fat. In comparison to fats, carbohydrates and proteins have about 4-5 calories per gram only. Because of this, it is easier to consume more calories with saturated fat intake, which can lead to weight gain.
Fat storage - When you consume more fat than what’s needed for the body, excess fat is stored in the adipose tissues. When you consume excess saturated fats, your adipose tissue grows and you start putting on weight.
Taste - Fatty foods are generally tastier. Think of buttery bacon, fried chicken, sweet pastries, or a big slice of cheesy pizza. They get addictive with time and this is another non-genetic factor that causes gradual weight gain.
Food combinations - Most packaged foods/ takeaways/ restaurant meals are a mix of carbohydrates and saturated fats. While carbohydrates give the body the needed energy, the excess fat you consume is mostly not used. This gets stored in the body, leading to weight gain.
Excess Proteins and Weight Loss
While a high-protein diet will help with weight loss, when you start consuming excess proteins just to lose weight, experts say this could backfire.
Excess proteins in the body are stored as fat and this will result in weight gain with time. This is especially true when you consume excess calories on a high-protein diet.
Here are other possible side-effects of excess protein consumption:
- Gastrointestinal problems like indigestion and diarrhea
- Bad breath
- Kidney damage in people with pre-existing kidney conditions
- Choosing excess red meats as protein sources can increase the risks of heart diseases
- Red-meat based high-protein diet increases the risk of cancers
What Happens When You Are Protein Deficient?
- Kwashiorkor disease (characterized by fatty liver, edema, and swollen stomach)
- Hair loss, hair thinning
- Brittle nails
- Loss of muscle mass
- Tiredness and fatigue
- Stunted growths in children
- Loss of immunity
- Constant hunger leading to weight gain
Recommendations For Right Protein Intake To Lose Weight
- For those looking to increase their protein intake, plant-based proteins are the best. These are safer and excess consumption does not lead to risks of cardiovascular problems or cancer.
- For meat lovers, seafood, turkey, and chicken are good sources of proteins that are healthier too.
- Make sure you include a variety of protein-rich foods throughout the day. This will ensure you get your sources of essential amino acids just from foods.
- Protein supplements can help those looking to quickly shed weight. Talk to your doctor/nutritionist about this.
- Genetics can play a role in deciding how helpful proteins are for weight loss. Get your genetic testing done.
- Choose healthier, fresh protein sources and stay away from packaged, processed, and canned foods. These end up causing more harm.
- Proteins are one of the most important macronutrients needed for survival.
- The amino acids in proteins help in hundreds of essential functions in the body.
- A high-protein diet helps in weight loss both genetically and non-genetically.
- Choose fresher and healthier protein sources to get maximum benefits from this macronutrient.
- For people looking to lose excess weight, a well-designed diet plan and protein supplements make a great difference.
- Include a variety of foods in your diet to stay healthy and fit.