Тағамнан алынатын химиялық энергия

Chemical energy animals derive from food

Food energy is chemical energy that animals (including humans) derive from their food to sustain their metabolism, including their muscular activity. The energy contents of a complex dish or meal can be approximated by adding the energy contents of its components.

The first determinations of the energy content of food were made by burning a dried sample in a bomb calorimeter and measuring the temperature change in the water surrounding the apparatus, a method known as direct calorimetry.

The typical human diet consists chiefly of carbohydrates, fats, proteins, water, ethanol, and indigestible components such as bones, seeds, and fibre (mostly cellulose). Carbohydrates, fats, and proteins typically comprise ninety percent of the dry weight of food. Ruminants can extract food energy from the respiration of cellulose because of bacteria in their rumens that decompose it into digestible carbohydrates. Other minor components of the human diet that contribute to its energy content are organic acids such as citric and tartaric, and polyols such as glycerol, xylitol, inositol, and sorbitol. Some nutrients have regulatory roles affected by cell signaling, in addition to providing energy for the body. According to the Food and Agriculture Organization of the United Nations, the average minimum energy requirement per person per day is about Notwithstanding, nutrition labels on Australian food products typically recommend the average daily energy intake of
The minimum food energy intake is also higher in cold environments. Increased mental activity has been linked with moderately increased brain energy consumption.