Fat Loss

Last Updated: November 20 2022

Fat loss occurs when more calories are expended than consumed.

How does fat loss work?

There are three components of total daily energy expenditure: the thermic effect of food (i.e., the energy cost of the digestion, absorption, and storage of dietary macronutrients), basal metabolic rate, and physical activity, which can be subdivided into volitional exercise and nonexercise activity thermogenesis (i.e., the energy expended performing common daily activities such as standing, walking, and fidgeting). For fat loss to occur, energy intake must be less than energy expenditure.

How could diet affect fat loss?

There are no meaningful differences in fat loss between diets that vary in carbohydrate and fat content, as long as their protein and calorie content is equal.[1][2]

Nonetheless, certain dietary factors can influence fat loss via their effects on energy expenditure, hunger, and satiety, and thus energy intake. These include ultraprocessed foods, which have been shown to increase ad libitum energy intake;[3] protein, which has the highest thermic effect of food among the macronutrients, helps to preserve muscle during weight loss (and thus preserve basal metabolic rate), and may reduce hunger and prolong satiety;[4] and fiber, which may also reduce hunger and prolong satiety.[5]

Which supplements are of most interest for fat loss?

Supplements of interest for fat loss typically either increase total daily energy expenditure, suppress appetite, or increase the rate at which fatty acids are released from fat cells. The following are some of the most popular supplements related to fat loss:

Most supplements sold for fat loss are ineffective or there’s not enough evidence in humans to support their efficacy, and some can even be harmful. For example, yohimbine, ephedrine, and caffeine can all induce anxiety in some people.

Join our supplement information course

Enter your email for a FREE five-day course on supplements. Get only the information that’s 100% backed by science. We take an independent and unbiased approach to figure out what works (and what’s a waste of time and money).

Examine is the only 100% independent company in the nutrition and supplement industry. While everyone else sells supplements and works with sponsors, we exclusively analyze research.

    The only 100% independent company. While everyone sells supplements, we only analyze research.

    Don't miss out on the latest research

    Become an Examine Insider for FREE to stay on top of the latest nutrition research, supplement myths, and more