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In human nutrition, empty calories are those calories found in foods and beverages (including alcohol) [1] composed primarily or solely of calorie-rich macronutrients such as sugars and fats, but little or no micronutrients, fibre, or protein. [2] Foods composed mostly of empty calories have low nutrient density, meaning few other nutrients ...
The calorie is a unit of energy that originated from the caloric theory of heat. [ 1 ][ 2 ] The large calorie, food calorie, dietary calorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter of water by one degree Celsius (or one kelvin). [ 1 ][ 3 ] The small calorie or gram calorie is defined as ...
Specific energy or massic energy is energy per unit mass. It is also sometimes called gravimetric energy density, which is not to be confused with energy density, which is defined as energy per unit volume. It is used to quantify, for example, stored heat and other thermodynamic properties of substances such as specific internal energy ...
The calorie is defined as the amount of thermal energy necessary to raise the temperature of one gram of water by 1 Celsius degree, from a temperature of 14.5 °C, at a pressure of 1 atm. For thermochemistry a calorie of 4.184 J is used, but other calories have also been defined, such as the International Steam Table calorie of 4.1868 J .
For an overall efficiency of 20%, one watt of mechanical power is equivalent to 18 kJ/h (4.3 kcal/h). For example, a manufacturer of rowing equipment shows calories released from "burning" food as four times the actual mechanical work, plus 1,300 kJ (300 kcal) per hour, [16] which amounts to about 20% efficiency at 250 watts of mechanical output.
Calorimetry requires that a reference material that changes temperature have known definite thermal constitutive properties. The classical rule, recognized by Clausius and Kelvin, is that the pressure exerted by the calorimetric material is fully and rapidly determined solely by its temperature and volume; this rule is for changes that do not involve phase change, such as melting of ice.
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose (glucose + fructose ...
Foods high in magnesium (an example of a nutrient) Human nutrition deals with the provision of essential nutrients in food that are necessary to support human life and good health. [ 1 ] Poor nutrition is a chronic problem often linked to poverty, food security , or a poor understanding of nutritional requirements. [ 2 ]