Question: How much exercise do we need to do to prevent obesity?

Fiona Hatch answered on 13 Mar 2012:

This is a very interesting question which a lot of adults get wrong even today. The shocking truth is that exercise alone will not prevent obesity. Someone could exercise for many hours a day, but if they eat too much food, then they will get fat. Your body always uses energy, everytime you breath or move you use a certain amount of energy. It is important you get enough energy by eating food so that you can do all you need to do in your day. But people get obese when they take in more energy than they actually use up.

To keep healthy you should follow one simple rule: Energy in = Energy out.

So if you eat 10 chocolate bars in one day, that is a lot of energy coming into your body, you will then have to exercise for 4 hours or more to get rid of it and to stop you getting fat. But if you ate half a chocolate bar in a day then you only have to exercise for 30 minutes to use up that energy.

So the amount of exercise you need to stop obesity depends on what you’re eating. If you eat healthy food then a small amount (10-20 minutes) of exercise per day will keep you healthy.