more at http://food.quickfound.net
Basic primer on watching your calories to avoid getting fat. Includes some amusing stop motion animation of food on a dinner table.
Public domain film from the Prelinger Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The film was silent. I have added music created by myself using the Reaper Digital Audio Workstation and the Independence and Proteus VX VST instrument plugins.
Food energy is energy that animals (including humans) derive from their food, through the process of cellular respiration, the process of joining oxygen with the molecules of food (aerobic respiration) or of reorganizing the atoms within the molecules for anaerobic respiration.
Humans and other animals need a minimum intake of food energy to sustain their metabolism and drive their muscles. Foods are composed chiefly of carbohydrates, fats, proteins, water, vitamins, and minerals. Carbohydrates, fats, proteins, and water represent virtually all the weight of food, with vitamins and minerals making up only a small percentage of the weight. Carbohydrates, fats, and proteins comprise ninety percent of the dry weight of foods. Food energy is derived from carbohydrates, fats and proteins as well as organic acids, polyols, and ethanol present in the diet. Some diet components that provide little or no food energy, such as water, minerals, vitamins and fiber, may still be necessary to health and survival for other reasons. Water contains very stable chemical bonds and so cannot be oxidized to provide energy. Vitamins and minerals are present in very small amounts (in milli- or micrograms) and also cannot be used for energy. Fiber, a type of carbohydrate, cannot be completely digested by the human body. Ruminants can extract food energy from the respiration of cellulose thanks to bacteria in their rumens.
In the International System of Units, energy is measured in joules (J) or its multiples; the kilojoule (kJ) is most often used for food-related quantities. An older metric system unit of energy, still widely used in food-related contexts, is the calorie; more precisely, the "food calorie", "large calorie" or kilocalorie (kcal or Cal), equal to 4.184 kilojoules. (It should not be confused with the "small calorie" (cal) that is often used in chemistry and physics, equal to 1/1000 of a food calorie.) Within the European Union, both the kilocalorie ("kcal") and kilojoule ("kJ") appear on nutrition labels. In many countries, only one of the units is displayed; in the US and Canada the unit is spelled out as "calorie" or "Calorie".
Fats and ethanol have the greatest amount of food energy per mass, 37 and 29 kJ/g (8.8 and 6.9 kcal/g), respectively. Proteins and most carbohydrates have about 17 kJ/g (4.1 kcal/g). Carbohydrates that are not easily absorbed, such as fiber, 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 amount of water, fat, and fiber in foods determines their energy density...
Recommended daily intake
Recommendations in the United States are 2,700 and 2,100 kcal (11,000 and 8,800 kJ) for men and women (respectively) between 31 and 50, at a physical activity level equivalent to walking about 1.5 to 3 miles per day at 3 to 4 miles per hour in addition to the light physical activity associated with typical day-to-day life, with French guidance suggesting roughly the same levels.
Children, those with sedentary lifestyles, and older people require less energy; physically active people more. In Australia, because different people require different daily energy intakes there is no single recommended intake. Instead there is a series of recommendations for each age and gender group, although packaged food and fast food outlet menu labels refer to the average Australian daily energy intake of 8700 kJ (2079 kcal).
According to the Food and Agriculture Organization of the United Nations, the average minimum energy requirement per person per day is about 1,800 kcal (7,500 kJ)...