First of all, we need to clarify the difference between hunger and appetite.
Hunger or the need to eat, is controlled by signals from the gut; signals from energy stores carried by the blood, hormones and body temperature. Appetite is the desire or liking to eat rather than need to eat.
So, what effect does exercise have on our hunger/appetite levels? Does more exercise equal increased hunger or an increased appetite for healthier foods? Can exercise suppress hunger? Will you eat less when you stop exercising?
- Does exercise increase hunger?
There is no evidence to support this idea and generally, doing exercise does not automatically increase hunger. Some exercise may actually suppress it.
- Does exercise help you make healthier choices?
There is a possibility that exercising may increase your appetite for healthier foods. For example, if you are hot and sweaty after a session, you may prefer to eat fruit, vegetables and water rather than fatty, sugary foods. However, this area has not been thoroughly researched.
- Does exercise suppress appetite?
Extreme exercise such as marathon running can have a moderate hunger suppression effect which can last for a several hours after exercise whereas moderate exercise does not seem to have any effect.
- Do you eat less when you stop exercising?
Unfortunately the answer is a definite no. Consider professional athletes – they have a special diet which provides more calories than the average person would eat. This is designed to ensure they have the energy to train for many hours a day and to help their bodies perform at their peak. However, when they decrease their training (e.g. off season), their calorie intake is reduced accordingly. This implies that social and psychological factors determine how much and what we eat.
How does exercise suppress your appetite?
It is unknown exactly how the appetite suppressant effect is caused by vigorous exercise but there could be a link to raised body temperature as this may reduce the amount of food consumed. On the other hand, exercising in the cold has been shown to increase the amount of food eaten afterwards.
What does this mean for the average exerciser?
Until there has been further research clarifying the effect of exercise on appetite and hunger, it is a good idea to ensure you have a healthy diet and stick to it when exercising and decrease your calorie intake when you have a break from exercise.