|What are Proteins|
|Daily Protein Requirement|
|Animal Protein vs Plant Protein|
|Sources of Protein|
Proteins are called the building blocks of the body. They are a part of every cell of the human body and play a crucial role to repair existing cells and make new ones. This aids in muscle repair and development. No wonder the protein requirement remains important at all stages of life. But the daily protein requirement depends upon various factors like age, gender, weight, and exercise levels. Read through to know what your protein requirement per day is.
What are Proteins?
Proteins, along with fats and carbohydrates, provide energy to the body. One of the three primary macronutrients, proteins, is responsible for the work done within the cell membrane. It is crucial for cell structure and aids in the proper functioning of tissues and body organs.
Proteins are made up of amino acids which are necessary for building and repairing muscles and bones. They are vital for hormone and enzyme production and are an excellent source of energy.
For proper functioning of the body, a total of 20 different essential amino acids are required by the body. These are:
- Aspartic acid
- Glutamic acid
Depending upon the placement or sequence of amino acids, a protein’s structure and function are determined. Proteins can be divided based on the function they perform. These are:
- Antibodies – proteins which protect the body from foreign invaders
- Enzymes – proteins that carry out the chemical reactions in the body
- Messenger – proteins responsible for transmitting signals to and from the brain
- Structural component – proteins that allow the cells to repair and multiply
- Transport – proteins that aid the movement of molecules in the body
Daily Protein Requirement
How much protein you will require per day will depend upon various factors. These are:
1. Protein Requirements By Age
As people age, they need more proteins to maintain muscle mass and strength. Protein requirement also increases for physiological functions.
The daily protein requirement for a child aged between 1 and 3 years is 13 g, whereas it increases to 19 g for children aged between 4 and 8 years and 34 g for children aged between 9 and 13 years.
As kids enter teenage, a female teen ageing between 14 and 18 years will require a minimum protein per day of 46 g, whereas, a male teen ageing between 14 and 18 years will require 52 g.
The daily protein requirement for females is 46 g, whereas the daily protein requirement for male is 56 g.
In old age, the intake of food decreases. This affects protein intake, resulting in loss of muscle mass and strength. The daily protein requirement for older adults is between 1g and 1.2g per kg of body weight. Also, the frequency of protein intake must be high. Almost every meal must contain some healthy source of protein.
2. Protein Requirement During Pregnancy and Lactation
The protein requirement of females further increases in case she is pregnant or breastfeeding. The minimum protein per day for pregnant or breastfeeding women is 71 g.
3. Protein Requirement by Weight
In some cases, the protein requirement per day is calculated based on the weight of the individual. When calculating protein requirement by weight one must get a minimum of 10% of the daily calories by way of proteins. But this must not exceed 35% of total daily calories.
According to commonly used estimates, the minimum protein per day is 0.8g/kg of body weight. For example, the daily protein requirement for female who weighs 50 kg will be 40 g (0.8g X 50 kg weight)
4. Protein Requirement by Activity Level
Protein requirement per day increases for highly active people. This is because proteins are vital for muscle recovery after a strenuous workout.
The recommended protein requirement per day ranges between 0.8 g/kg and 2 g/kg of body weight. This depends upon the activity level and muscle building training. The activity levels of a person can be divided into six sub-categories. These are:
- Sedentary lifestyle – No exercise at all
- Light exercise – 1-3 days a week
- Moderate exercise – 4-5 days a week
- Active exercise – daily exercise or intense exercise 3-4 days a week
- Very active – intense exercise 6-7 days a week
- Extra active – intense workouts every day or a physical job
Therefore, the daily protein needed to build muscle for athletes and fitness enthusiasts can go up to 2g/kg of body weight.
For example, the daily protein requirement for female who weighs 50 kg and is into strenuous gym training and muscle building must take 100 g (2g X 50 kg weight) of protein per day. But remember, the protein requirement per day must not exceed 35% of total daily calorie intake in any case.
Consistently low intake of proteins can lead to severe health problems. Protein deficiency in children is a known cause of malnutrition, leading to life-threatening conditions like kwashiorkor and marasmus. The signs and symptoms of low protein intake are:
- Weak muscle strength
- Thin, brittle hair
- Swelling due to fluid retention
- Skin lesions
- Loss of muscle mass in adults
- Stunted growth in children
Like protein deficiency, overuse of proteins is equally harmful to health. Overconsumption of proteins can raise serious health concerns.
Extra protein intake is not used effectively by the body. Excessive proteins produce huge amounts of acid in body fluids. This causes a metabolic burden on the kidneys and liver. Because of increased acid levels, the bones begin to corrode, resulting in excessive calcium loss. This increases the risk of osteoporosis in old age.
Moreover, the extra protein intake, if sourced through animal proteins, raises the risk of coronary heart disease and cancers. The extra proteins consumed are typically stored as body fat, leading to weight gain. A high-protein diet may raise digestion concerns and may lead to diarrhoea or constipation. The signs and symptoms of protein overuse include:
- The feeling of nausea and vomiting
- Perpetual headaches
- Frequent mood changes
- Weakness and fatigue
- Hypotension or low blood pressure
- Hunger and food cravings
- Bradycardia or slow heart rate
Animal Protein vs Plant Protein
Of the total 20 amino acids required by the body, nine cannot be synthesised within. Therefore, these nine essential amino acids have to be obtained from dietary sources. Dietary sources of protein can include plant-based and animal-based proteins depending upon where they are sourced from.
Animal protein is said to be ‘complete protein’ as it contains all nine essential amino acids that the body cannot synthesise. On the other hand, plant-based protein is referred to as ‘incomplete protein’ as most plant-based foods miss out on at least one of the nine essential amino acids. However, quinoa, buckwheat, soybeans, nutritional yeast, chia and hemp seeds are an exception to this. These plant-based proteins contain all nine essential amino acids, making them a source of complete protein.
Furthermore, animal sources of protein contain high levels of heme iron and vitamin B-12. Heme iron is more readily absorbed by the body. Plant-based protein sources invariably lack these nutrients. On the other hand, plant-based protein sources are rich in phytonutrients and some antioxidants, which are not present in animal-based protein sources.
Therefore, it is important to mix all protein sources well. This will ensure that the body gets all of the nine essential amino acids that the body cannot synthesise.
Sources of Protein
Protein in food can be obtained through plant protein or animal protein. High protein food items in both categories are:
Plant Protein Sources:
- Fruits like avocados
- Soy products like tofu, tempeh, and edamame
- Hemp seeds
- Ezekiel bread
- Chia seeds
- Nutritional yeast
Animal Protein Sources:
- Whole eggs
- Fish and seafood
- Lean meat
- Wild game
- Dairy products such as milk, yoghurt, and cheese
Proteins are crucial for maintaining well-being at every age. Besides the basic function of muscle strengthening and repair, proteins carry out an array of functions within the body cells. No wonder, chronic protein deficiency can spur the risk of life-threatening conditions. Ironically, protein overuse can be equally detrimental. Thus, sticking to the recommended daily protein requirement is the key to good health.
Calculate your protein requirement per day based on your age, weight, and activity levels to seek advantages from the macronutrient. While it is not necessary to eat only complete proteins, make sure you add a sufficient variety of different foods to get all the essential amino acids.