There would not have been a single day in your life since adulthood, which has passed without some thoughts on food. Yet, how many of us have made some sensible thinking on food and gave a reasonable attention it deserves. This itself is quite fascinating, considering the fact that we cant survive without food. Any way you deserve a pat on your shoulder as you have decided to build up your weight. In order to have a better understanding of the chemistry of weight gain, let us go through the minute details pertaining to calorie, energy, body mass index and similar parameters.

The energy that a given food can release during metabolism is measured in calories per gram.

A calorie (cal) is defined as the amount of heat required for raising the temperature of 1 kg of water through 1 degree Celsius. Nutritionists measure the energy content of foods in kilocalories (1 kcal = 1000 cal) and calories. Normally, an adult requires 1200-1800 calories a day to maintain basic life processes, and an additional 50-150% of this amount to meet the energy requirements of physical activities. In other words calories consumed also differ according to the activities.

A sleeping person spends 50-75 cal/hr. A person doing some other activities like swimming, playing basketball, or shoveling snow may consume ten times as many, or even more. One pound ( 0.45 kg ) of body fat is almost equivalent to 3500 calories of stored food energy. Calorie consumption, increases in direct proportion to body weight. Your body adds or loses weight depending upon a simple formula. If you are consuming more energy through food, than your body actually burns, then body weight is likely to increase. So, this primary rule ensures that you have to consume more calories than you spend through work, exercises and body activities.

I would like to say from my experience that there is a basic Principle of Nutrition that is universally true. In its most simplified form, the basic equation of Health can be written as Health = Nutrition + Calories. There is no dearth of information about health and nutrition. In fact its this abundance of literature that often perplexes one that how healthy could good nutrition make people be, and how much deviation from ideal nutrition could we allow ourselves. Remember, KNOWLEDGE is crucial during your weight gain process.