Question: what happens if you eat less food than normally @richard :)

Richard Sulston answered on 14 Mar 2016:

When the number of calories eaten is less than the number of calories used the body needs to find a way to either increase the number of calories it can use or reduce the number of calories it uses. To get more calories the body uses it’s energy stores starting with glycogen (long chains of sugar stored in the muscles and liver) and then fat which are both used to provide extra energy to the body. People eating less than they need will feel tired and sluggish as the body aims to conserve energy and may also feel colder, so its important eat as much as our bodies need to work properly.

I study a specific type of reduction in food intake called “calorie restriction”. This has been mostly studied in mice and rats and is a 30% reduction in daily calories whilst maintaining the correct daily nutrients such as vitamins and minerals. Previous research has shown that mice and rats on calorie restriction show reduced signs of diabetes, less cardiovascular disease, less cancer and live longer lives. I study a hormone which has been shown to increase in calorie restriction and decrease in obesity and so may be providing some of the beneficial effects of calorie restriction.