energyyielding

Energyyielding refers to substances and nutrients that can be oxidized by living organisms to produce usable energy. In human nutrition the primary energy-yielding nutrients are carbohydrates, fats, proteins, and alcohol. These substances provide energy measured in kilocalories (kcal) or kilojoules (kJ) and are distinguished from non-energy-yielding components such as dietary fiber, vitamins, minerals, water, and other micronutrients.

In dietary practice, energy yield is commonly estimated using the Atwater factors: carbohydrates give about 4 kcal/g, proteins about 4 kcal/g, fats about 9 kcal/g, and alcohol about 7 kcal/g. Fiber and other non-digestible components contribute little or variable energy, depending on gut fermentation, and are typically not counted as major energy contributors. The concept also encompasses the broader biochemical view that energy yield arises from the oxidation of substrates through metabolic pathways, ultimately producing ATP to power cellular processes.

The idea of energy yield is central to energy balance and nutrition planning. Diets are often evaluated by their content of energy-yielding nutrients to meet daily energy requirements while supporting maintenance, activity, and health. In physiology, energy yield relates to how efficiently substrates are converted into usable energy, influenced by metabolic state, hormonal regulation, and overall health.

Overall, energyyielding describes the class of nutrients and substances that supply usable energy for bodily functions, in contrast to non-energy-providing components.