The information resource about Nutrients, Probiotics and Food Supplements
Nutrient Details For : Energy

A nutrient is any element or compound necessary for or contributing to an organism's metabolism, growth, or other functioning. Click name for details Arsenic Biotin Boron Calcium Carbohydrates Carnitine Carotenoids Chloride Choline Chromium Copper Energy Fiber Fluoride Folate Iodine Iron Lipids Magnesium Manganese Molybdenum Niacin Nickel Pantothenic acid Phosphorus Phyto-chemicals Potassium Protein Riboflavin Selenium Silicon Sodium Thiamin Vanadium Vitamin A Vitamin B 12 Vitamin B 6 Vitamin C Vitamin D Vitamin E Vitamin K Zinc Further Trace Elements

Energy is required for the functions of all biological systems.

Dietary (food) energy is commonly given in units of Calories or kilocalories, but the scientific terminology is joules. 1 cal = 4.184 Joule

1000 Joule or 1 KJ = 238 cal(ories) or 0.13 Kc

1000cal or 1Kc = 4184 j or 4.2 Kj

The primary sources of energy are fats, carbohydrates and protein. Alcohol (Ethanol) also contributes to the energy intake of individuals, but alcohol is not generally categorized as a nutrient.

The energy is obtained from these sources by our metabolism. Our bodies are very efficient in storing energy for future use. Stored energy is primarily in the form of fat in adipose tissue, but a small amount of carbohydrate is stored in the liver and muscle.
Intermediary metabolism converts the energy consumed into the forms for storage or into forms which are readily available for biological processes such as compounds with high energy phosphate bonds.

Since energy cannot be destroyed or created, over a period of time the energy consumed must be expended or accounted for by gains or losses in body tissues.

If energy intakes are less then expenditures, body weight loss will occur. When energy intakes exceed expenditures, body weight gain will occur.

Energy expenditures are based on: Energy Needs = Basal metabolic rate (energy to keep heart beating, breathing, etc.) + physical activity + Thermic effect of feeding (energy required to convert energy by our metabolism).

Diet recommendations:

Recommended dietary allowances for energy are based on Median Heights and Weights set by the Food and Nutrition Board.

The average energy allowance for infants (0.5-1.0 years, 9 kg or 20 lb, 71 cm or 28 in) is 98 kcal/kg or 850 kcal/day.

The average energy allowance for children (4-6 years, 20 kg or 44 lb, 112 cm or 44 in) is 90 kcal/kg or 1,800 kcal/day.

The average energy allowance for males (11-14 years, 45 kg or 99 lb, 157 cm or 62 in) is 55 kcal/Kg or 2,500 kcal/day.

The average energy allowance for males (25-50 years, 79 kg or 174 lb, 176 cm or 70 in) is 37 kcal/kg or 2,900 kcal/day.

The average energy allowance for females (11-14 years, 46 kg or 101 lb, 157 cm or 62 in) is 47 kcal/kg or 2,200 kcal/day.

The average energy allowance for females (25-50 years, 63 kg or 138 lb, 163 cm or 64 in) is 36 kcal/kg or 2,200 kcal/day.

There is wide variation in the energy requirements of individuals, mainly due to differences in body size and physical activity. The energy allowances above are for individuals with average heights and weights, and light to moderate activity levels. The recommended allowances should be adjusted to account for increased physical activity and for larger or smaller body size.

Starvation - Inadequate energy intake:

Starvation continues to be a major world problem. Fortunately, starvation because of inadequate food availability is almost unheard of in the US. However, self imposed starvation is recognized in a proportion of people in the US with anorexia nervosa.

Obesity - Excessive energy intake:

Obesity is a major health problem in developed countries in the world. It has been estimated that 25-35% of the US adult population is obese. Obesity is associated with increased risk for cardiovascular disease, hypertension, stroke, diabetes and for certain cancers (endometrial, colon, ovarian and breast).

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