What is energy in foods?

Energy :

Our body needs a balance in energy. Energy balance in an individual depends on his or her dietary energy intake and energy expenditure. Imbalance in energy intake and expenditure results in gain or loss of body components resulting in changes in body weight. Excess energy cannot be eliminated, and is eventually deposited in the form of body fat which results in obesity.

Energy is calculated in Calories and calories are obtained from food. We calculate the energy (calories ) given by one food using the contents of the food.

The Estimated Energy Requirement (EER) is the average dietary energy intake that is predicted to maintain energy balance in a healthy, adult of a defined age, gender, weight, height, and level of physical activity consistent with good health.

So energy requirements vary by each individual and so average energy estimation helps to set a normal standard for people. Energy requirements also depends on each persons' Basal metabolic rate (BMR).

To calculate ones energy requirements we need to know Basal Energy Expenditure (BEE) ,Diet induced Energy Expenditure (DEE) and Activity-induced Energy Expenditure (AEE)
BEE refers to the metabolic activity necessary to sustain life (i.e., respiration, pulse, body temperature) or the energy needed in resting condition and can be estimated using the following equation:
Harris-Benedict equation:
BEE(kcal/day):Males = 66.5 + (13.7 X W) + (5.0 X H) - (6.8 X A)
Females = 655 + (9.6 X W ) + (1.7 X H) - (4.7 X A)
where:
W = usual or adjusted weight in kilograms
H = height in centimeters
A = age in years

Diet -induced Energy Expenditure includes energy costs of food absorption, metabolism and storage. DEE in individuals is relatively small and doesnot make important contirbution in energy balance.
Total energy Expenditure (TEE) = BEE + Activity-induced Energy Expenditure (Physical activity,PA )

Or the total energy expenditure is calculated by multiplying BEE with PA factor.

The physical activity factor varies between individuals depending on the duration and intensity of activities they perform. The PA factor vaires from 1.2 - 2.2 between individuals 18 and 64 year old healthy adults. On an average it is estimated the people having western life style ,regular ,relatively sedentary lifestyle have PA between 1.2-1.6 and that of elite athelets can be greater than 2.5

On an average the energy needed by individual is given below.
Men ~2300-2600 kcal
Women ~1900-2200 kcal
Pregnant +500 kcal

Lactating +600 kcal

Making good use of basic nutrition Information

We all know that we need energy to sustain the body’s various functions, including respiration, circulation, physical work, and maintenance of core body temperature.

And we also know that

- we get that energy from food which is broken down by various metabolic activities inside our body to release energy.
- Macronutrients include carbohydrate, fat and protein, micro nutrients are vitamins and minerals.
- Water is an essential nutrient, is needed to carry other nutrients throughout the body and 60% of our body is water.
- Too much of food gets stored as fat and leads to obesity and other diseases.

But we do get confused when it comes to eating right. We get questions like, how much of what I need to eat? How much is enough? Am I getting enough if I eat this? And how much calorie I need per day? What if I take too much calorie?

To answer all these questions we need to know the basic of nutrition. That is to know about energy, calorie, RDA ( recommended Daily allowance ) ,DRI (Dietary reference intake ), AI (Adequate intake) and BMI (body mass index)

In the next few blogs I want to put all the information together which is the key that will unlock the door to better diets and in turn better health and longer lives.