By Satya Mohapatra
Nutrition is the study of how the body breaks down food, which is termed as catabolism. The way it repairs and creates cells and tissues is termed as anabolism. When catabolism and anabolism are combined together, it is known as metabolism.
Nutrients are substances that allow our body to make energy, build and maintain tissues, and more importantly to regulate bodily processes. Nutrients are categorised into carbohydrates, proteins, and fats, which come the category of macronutrients.
These are required in large quantities. Vitamins, minerals, fibre and probiotics, and water – these come under the category of micronutrients. These are required in small substances.
Consumption of the above mentioned macronutrients and micronutrients goes through the process of catabolism and anabolism. This is done through metabolism and this requires calories affecting energy balance of a living being.
A calorie is a unit of energy – every cell in the body require energy to function in its optimal state. The calorie is defined as the amount of heat needed to raise the temperature of one kilogram of water from 0 to 1 degree Celsius. One gram of carbohydrate contains 4 calories, while one gram of Protein and fat contain 4 and 9 calories respectively. Do note that only macronutrients – carbohydrates, proteins and fats – have calories whereas the micronutrients have zero calories in them.
Some other things like alcohol and junk food also have zero calories. They have no nutrients in them either. These create havoc inside our bodies and cause ill-health. When we talk about energy balance, we talk in terms of calorie in. When we discuss about calorie out that is the calorie the body burns. Thus we need to know our basal metabolic rate (BMR), total daily energy expenditure (TDEE), thermic effect of food (TEF) and thermic effect of activity (TEA).
These are the basic things we should know to understand nutrition, diet and wellness.
(Professor Mohapatra is a noted dietician)
