Diets affect the "energy in" component of the energy balance by limiting or altering the distribution of foods. Techniques
that affect the appetite can limit energy intake by affecting the desire to overeat.
Consumption of low-energy, fiber-rich foods, such as non-starchy vegetables, is effective in obtaining satiation (the feeling of "fullness"). Exercise is also useful in controlling appetite as is drinking water and sleeping. (Extreme physical fatigue, such as experienced by soldiers and mountain climbers, can make eating a difficult chore.)
The use of drugs to control appetite is also common. Stimulants are often taken as a means to
suppress (normal, healthy) hunger by people who are
dieting. Ephedrine (through facilitating the release of adrenaline and noradrenaline) stimulates the alpha(1)-adrenoreceptor subtype, which is known to induce hypophagia (appetite suppression). L-Phenylalanine, an amino acid found in whey protein powders also has the ability to suppress appetite by increasing the hormone cholecystokinin (CCK) which sends a satiety signal to the brain.