What do Atwater factors represent?
A system for allocating energy values to foods. It was developed in the 19th century by the American chemist W. O. Atwater. The system uses a single energy value (factor) for each of the main groups of energy nutrients (protein, fat, and carbohydrate), regardless of the food in which it is found.
How do you calculate the fuel value of food?
The amount of grams of each energy source (fat, carbohydrate, and protein) and the amount of energy per gram of each energy source is given on the label. Multiply the grams by the Energy per gram to obtain the Energy.
Are Atwater factors gross energy?
The Atwater factors have important shortcomings. The gross energy contents of dietary proteins, fats, and carbohydrates are not constants. Other chemical components in foods other than protein, fat, and available carbohydrates contribute energy and may influence the ME of the principal chemical components.
How do you calculate protein energy intake?
To calculate the percentages of energy intake from protein and carbohydrate to total energy intake (protein energy ratio and carbohydrate energy ratio), intake of 1 g protein and 1 g carbohydrate was multiplied by 4 kcal. An intake of 1 g fat was multiplied by 9 kcal to calculate fat energy ratio.
What is the Atwater factor for alcohol?
The Atwater general system also includes alcohol with a rounded value of 29 kJ/g (7.0 kcal/g or an unrounded value of 6.9 kcal/g) (Atwater and Benedict, 1902).
What is Atwater indirect system?
Today, producers use the “Atwater indirect system” to calculate calories by adding up the calories provided by the energy-containing nutrients: protein, carbohydrate, fat and alcohol.
What is the Atwater method?
The Atwater system is used in the food industry to determine the total calorific value of food by employing the 4-9-4 method. This system applies energy conversion factors to the macronutrients carbohydrate, fat, protein and fiber. Alcohol is also technically considered a macronutrient and contains 7 kcal/g (29 kJ/g).
How do you calculate food labels?
To calculate this, divide a food or drink’s calories from fat by total calories (this information is on the product’s food label) and then multiply by 100. For example, if a 300-calorie food has 60 calories from fat, divide 60 by 300 and then multiply by 100.
What is the Atwater equation?
Calculated with modified Atwater equation (AAFCO, 1997): ME (kcal/kg) = 10 × (3.5 × Crude Protein % + 8.5 × Crude Fat % + 3.5 × Nitrogen-Free Extract %).
How do you calculate energy requirements?
How the calculation works
- BEE = 293 − 3.8 × age (years) + 456.4 × height (meters) + 10.12 × weight (kg)
- BEE = 247 − 2.67 × age (years) + 401.5 × height (meters) + 8.6 × weight (kg)
- Low active: PA = 1.12, when 1.4 ≤ PAL <1.6.
- Very active: PA = 1.54, when 1.9 ≤ PAL <2.5.
- Low active: PA = 1.14, when 1.4 ≤ PAL <1.6.
What type of energy do Atwater factors represent?
3.5.1 The Atwater general factor system It uses a single factor for each of the energy-yielding substrates (protein, fat, carbohydrate), regardless of the food in which it is found. The energy values are 17 kJ/g (4.0 kcal/g) for protein, 37 kJ/g (9.0 kcal/g) for fat and 17 kJ/g (4.0 kcal/g) for carbohydrates.
How does the Atwater system work?
What are Atwater’s energy factors?
As mentioned previously, Atwater’s energy factors, the specific energy factors, take into account the physiological availability of the energy from these foods.
What are the variables in Atwater’s system?
The protein, fat and carbohydrate, alcohol contents are the variables, while the energy factors for the same compounds generally are treated as constants. However, in Atwater’s system there are eight variables on the right side of the equality sign as all the factors are variables.
What is the difference between me values determined by Atwater and Atwater?
The difference between ME calculated by using Atwater and similar factors and determined ME values was up to 4% for the refined diet and up to 11% for the low-fat, high-fiber diets. Various factorial and empirical systems for calculating food energy failed to reflect the results of the direct determinations.
What is the standard Atwater factor for fat?
The standard Atwater factor of 9.0 kilocalories (37.7 kJ) per gram of fat should be used for calculating the energy value of fat in all nutrition surveys and food composition tables; Standard methods and reference materials should be used in the analysis of the fatty acid content of foods and in the preparation of nutrient databases;