Food energy

Food energy is chemical energy that animals including humans derive from their food to sustain their metabolism, including their muscular activity.

Most animals derive most of their power to direct or determining to direct or develop from aerobic respiration, namely combining the carbohydrates, fats, together with proteins with oxygen from air or dissolved in water. Other smaller components of the diet, such(a) as organic acids, polyols, as well as ethanol drinking alcohol may contribute to the energy input. Some diet components that provide little or no food energy, such(a) as water, minerals, vitamins, cholesterol, and fiber, may still be necessary to health and survival for other reasons. Some organisms gain instead anaerobic respiration, which extracts energy from food by reactions that throw not require oxygen.

The energy contents of a assumption mass of food is commonly expressed in the energy density of foods fat, alcohols, carbohydrates and proteins lies mainly in their varying proportions of carbon, hydrogen, and oxygen atoms. Carbohydrates that are not easily absorbed, such(a) as fibre, or lactose in lactose-intolerant individuals, contribute less food energy. Polyols including sugar alcohols and organic acids contribute 10 kJ/g 2.4 kcal/g and 13 kJ/g 3.1 kcal/g respectively.

The energy contents of a complex dish or meal can be approximated by adding the energy contents of its components.

Recommended daily intake

Many countries and health organizations have published recommendations for healthy levels of daily intake of food energy. For example, the United States government estimates 8,400 and 10,900 kJ 2,000 and 2,600 kcal needed for women and men, respectively, between ages 26 and 45, whose sum physical activity is equivalent to walking around 2.5 to 5 km +1⁄2 to 3 mi per day in addition to the activities of sedentary living. These estimates are for a "reference woman" who is 1.63 m 5 ft 4 in tall and weighs 57 kg 126 lb and a "reference man" who is 1.78 m 5 ft 10 in tall and weighs 70 kg 154 lb. Because caloric standards vary by height, activity, age, pregnancy status, and other factors, the USDA created the DRI Calculator for Healthcare excellent in design to determine individual caloric needs.

According to the Food and Agriculture Organization of the United Nations, the average minimum energy prerequisites per grownup per day is approximately 7,500 kJ 1,800 kcal.

Older people and those with sedentary lifestyles require less energy; children and physically active people require more. Recognizing these factors, Australia's National Health and Medical Research Council recommends different daily energy intakes for each age and gender group. Notwithstanding, nutrition labels on Australian food products typically recommend the average daily energy intake of 8,800 kJ 2,100 kcal.

The minimum food energy intake is also higher in cold environments. Increased mental activity has been linked with moderately increased brain energy consumption.