One of the main problems with exercise and weight loss is that exercise doesn’t just affect the “calories out” side of the energy balance equation.
It can also affect appetite and hunger levels, which may cause you to eat more calories.
Exercise May Increase Hunger Levels
One of the main complaints about exercise is that it can make you hungry and cause you to eat more.
It’s also been suggested that exercise may make you overestimate the number of calories you’ve burned and “reward” yourself with food. This can prevent weight loss and even lead to weight gain (29, 30).
Exercise May Affect Appetite-Regulating Hormones
Physical activity may influence the hormone ghrelin. Ghrelin is also known as “the hunger hormone” because of the way it drives your appetite.
Interestingly, studies show that appetite is suppressed after intense exercise. This is known as “exercise anorexia” and seems tied to a decrease in ghrelin.
However, ghrelin levels go back to normal after around half an hour.
So although there is a link between appetite and ghrelin, it doesn’t seem to influence how much you actually eat (34).
Effects on Appetite May Vary by Individual
How exercise affects appetite and food intake varies between individuals. Some people may become more hungry and eat more, which can prevent weight loss.