Proteins are vital to life and are called as the Building Blocks of Life as it is necessary for physical development and organ and cell functions. As macronutrients in the diet, it helps in improving the body composition. It consists of chains of amino acids and contains carbon, hydrogen, oxygen and nitrogen.
The protein that comes from animal food sources is known as high biological value proteins as it provides a more complete amino acid mixture and the protein that comes from plant food sources are known as low biological value proteins and do not contain all the amino acids in adequate amounts.
The body contains a large amount of proteins in structure, enzymes and hormones and the function include serving as:
- Antibodies for the immune system.
- Hormones as regulators of metabolic processes
- Blood proteins for transporting nutrients and oxygen.
- Enzymes for digestion and absorption of food.
- An important energy source for muscle, liver and the intestine.
- Defend against infection as antibodies and participate in the body’s immune system.
- Help makes up the collagen and cartilage, which determines the shape of the skeleton.
A recent meta-analysis of 18 randomized controlled trials found that older adults (50+) can preserve lean body mass during weight loss more effectively when they consume a high-protein diet. Reduction in triglycerides, blood pressure and waist circumference were also reported. According to the study after higher–protein meals, the satiety hormones were elevated which resulted in greater perceived fullness and helped in reducing the quantity of meals.
When we eat protein, it is digested into its amino acids and smaller protein byproducts. These are further broken down in the liver which is drawn upon for energy or re-synthesized into other amino acids to suit the body’s physiological needs. As per the theory, proteins are the most satiating macronutrient and the feeling of satiety which is a process that leads to inhibition of further eating, decline in hunger and increase in fullness after a meal has finished. This has the potential to induce a negative energy balance and also preserve lean body mass and facilitate weight loss in overweight individuals.
But while following a weight loss diet, an excessive intake of protein than the recommended allowances increases the burden on two vital organs, namely the liver and the kidneys to metabolise and excrete the wastes arising from amino acid breakdown. When the planned diet consists of more protein and inadequate calories per day, then dietary protein gets oxidised as the source of energy and the breakdown of tissue protein happens. The protein-energy ratio differs for different ages and between the different activities
The calories that is been provided by the carbohydrates and proteins are the same i.e. 1gm of both of these nutrients gives 4kcals but the effect of these nutrients on our body differs. So the balance of both carbohydrates and proteins are required. This will spare proteins from being broken down rapidly for energy and restrict the proteins from getting utilized for bodybuilding and repair and regulatory and protective function. Protein utilization and deposition are dependent on the intake of adequate energy.
Follow a balanced diet with the recommended intake of proteins accompanied by an adequate amount of carbohydrates and micronutrients than depending on any supplements. So get a customized meal plan provided by an expert.
The food sources of proteins:
The food sources of protein are pulses (Whole and Splits), milk and milk products, eggs, fish and poultry and meat, nuts and oilseeds etc. We can provide ourselves with the best healthy meal by having a combination of these protein sources with our cereal-based meal along with vegetables and will provide us with all the nutrients in a balanced quantity and thus help in weight loss.
Ms. Nishitha Krishnan T | Clinical Nutrition & Dietetics | Narayana Medical Centre, Langford Town, Bangalore