PROTEIN – A CORE MACRONUTRIENT
Our body is made up of many building blocks known as amino acids.
Proteins, whereas made up of hundreds or thousands of smaller units called amino acids, are attached to one another in long chains.
Amino acids are small organic compounds linked together to form proteins. A different sequence of amino acids determines each protein’s unique 3-dimensional structure and its specific function.
What is the function of the protein in the human body?
Protein is arguably the most important yet most overlooked of all the macro-nutrients.
Everything from muscles, nails, hairs, bones to microscopic cellular machines, hormones, including catalyzing metabolic resources, DNA replication, structure to cells, and neurotransmitters in a human’s body are derived from proteins.
Figure 1. Functions of proteins in the body.
How much protein should we eat every day?
According to WHO, all sedentary males & females (average adults) are recommended to consume at least 0.83 grams of protein for every kilogram of body weight per day.
In other words, a 70 kg adult should aim to eat at least 58 grams of protein every day, that is 70 x 0.83 = 58 grams.
During periods of growth, such as childhood, pregnancy, and breastfeeding, protein requirements are relatively higher. The Dietary Reference Values (DRVs) according to the 2007 joint report of WHO for protein intake at different stages of life are summarised in tables below.
BW: body weight, R.Value: Reference value
Table 1: For both males and females.
| 18 – 60 Years|| 0.83 g / kg BW|
| More than 60 Years|| 1 g / kg BW|
Table 2: For both boys and girls.
|Growing Kids||Reference Value|
| 12 months – 3 Years|| 1 g / kg BW|
| 4 – 13 Years|| 1 g – 1.5 g / kg BW|
|14 -17 Years|| 1 g / kg BW |
Table 3: In addition to your total intake of an average adult’s reference value (i.e 0.83 g / kg BW).
|Pregnant Women||Added R.Value|
|First Trimester|| +1 g |
|Second Trimester|| +9 g |
|Third Trimester|| +31 g|
Table 4: In addition to your total intake of an average adult’s reference value (i.e 0.83 g / kg BW).
|Breastfeeding Women||Added R.Value|
|0 – 6 months||+19 g |
|6 – 12 months||+12.5 g |
NOTE: Depending on the goals of an active fitness enthusiast, they may need more protein in their diet than the recommended reference value for an average adult.
Essential Vs Non-essential Amino Acids
In order to derive Dietary Reference Values (DRVs) for safe protein intake, the concept of protein requirements includes some major factors like, having an optimal indispensable amino acid composition for human’s daily requirements which aids in faster digestibility & absorption of protein.
Amino acids are classified as either essential or non-essential. As the name suggests, essential amino acids cannot be produced by the body and therefore must come from our daily protein sources. Whereas, non-essential amino acids can be produced by the body.
Table 5: Essential Vs Non-essential Amino Acids
|Essential Amino Acids||Non-essential Amino Acids|
Alanine Asparagine Aspartate Glutamate Serine Arginine* Cysteine*
*marked are conditionally essential amino acids, are only essential in times of illness and stress or certain special conditions.
Animal Vs Plant-Based Sources
In general, an animal-based diet contains higher digestibility and higher proportions of all nine essential amino acids compared to plant-based proteins but eating only higher animal-based sources can also spike up your cholesterol and blood pressure levels with increased risk of cardiovascular diseases.
However, there is a common misconception that plant-based proteins completely lack essential amino’s. Plants, host a diverse range of amino acid profiles, but very few contain all nine essential amino acids. For people following a vegetarian or a vegan diet, the most common strategy is to regularly alternate between multiple plant-based sources or to combine various plant-based sources in your daily diet.
Therefore, it’s very important to choose a Sustainable Protein Diet in which you must combine various plant-based sources like gluten-free cereals, beans, lentils, and dairy with your lean animal sources. Also limiting your high meat consumption to 1-2 times a week, by having meat-free days in between, can help our world to maintain our ecological balance.
Figure 2. Lean and rich sources of proteins.
5 Benefits of Protein Diet
The power of a diet rich in protein has some major health benefits for weight loss and your metabolism rate.
1. Increases Muscle Hypertrophy. Our muscles are primarily made up of amino acids which can be produced from the process of breakdown called “Protein Synthesis“. High lean sources of proteins can help you gain Muscle Hypertrophy, higher athletic performance and aids your weight loss journey.
2. Makes You Feel Mindful & Light. Eating your proteins firstly in meals has a powerful influence on the fact of feeling fuller and helps to stop your brain from overeating simple carbohydrates.
3. Boosts Metabolism. The metabolism or thermal effect of your digestive system is affected by what you eat, Protein, in particular, stimulates the thermic effect of food, which means that the body burns more energy processing dietary protein than it does with carbohydrates or fats.
4. Helps You Recover Fast. Post-workout micro-trauma also known as muscle soreness occurs due to the breakdown of tissues in muscles, regular intake of high protein resources post-workouts can help you recover faster and grow even bigger muscle mass.
5. Healthier Ageing. Low protein intake increases the risk of sarcopenia with aging, which is a major reason for bone fractures and fragile joints with time. Staying physically active as well as eating lean sources of protein can help you fight muscle deterioration, sarcopenia, and skeletal disorders.
What happens if you eat too much protein?
Although adding protein to your diet may help boost your metabolism, but overconsumption of any macro-nutrient can lead to certain health issues over time. Take a look below:
1. Gaining Weight. When it comes to weight loss it’s all about creating the right calorie deficit and eating a balanced diet. A common misconception is, you can’t gain weight from protein. Well, according to research, excess protein consumed is stored as fat and higher dietary protein intake is associated with long-term increased risk of body weight gain.
2. Increased Cancer Risk. Eating large portions of red meat & full-fat dairy shown an elevated risk of coronary heart disease (CHD) due to the deposition of saturated fats & cholesterol. Whereas lean sources, like fish, poultry and nuts help to lower such risk.
3. Kidneys Damage. Higher protein intake can affect people suffering from preexisting kidney disease, because of the excess nitrogen found in amino acids it becomes harder for some to get rid of waste produced at the time of protein metabolism. While there is little to no evidence that a high protein intake is dangerous to healthy individuals
Protein is an essential building block of the human body, however, the most important thing is to understand your ideal amount of protein intake that you should consume keeping multiple factors in mind like, age, gender, activity, health, activities performed in a day and other Training Variables.
Our requirement for protein is directly proportional to our stage of growth in life, for an average adult to lead a healthy and sustainable life, they must consume an average of 0.8 grams of protein per kilogram (kg) of body weight.
However, some experts believe, people like elite athletes can even eat beyond 2 or 2.5 grams of protein per kg of body weight per day over the long term, while no study in the world can justify what is the most precise number for protein intake.
Different food & medical authorities have set a different amount of protein requirement which is dramatically more than those of the Recommended Dietary Allowance (RDAs) guidelines, and, therefore, it is important to understand the definition of RDA and the right amount (minimum required) to meet the needs of almost all (97 to 98%) individuals in a group.
An effective way to do so would be to ensure that at every meal 1/4th of your plate is filled with a rich source of protein.