In one of the largest studies of its kind, it has been shown that pregnant women who diet while carrying a child may not be harmful. In fact the study, carried out in more than 4000 pregnant women showed that active weight management, and avoiding the 'eat for two' philosophy, actually increased the health benefits to both mother and child.

At present more than half of the UK population are clinically obese or overweight. This puts people at increased risk of heart attack, stroke, type two diabetes as well as increased cholesterol and high blood pressure.

Treatment of these ailments related to being overweight costs the NHS millions of pounds each year.

However, other studies have shown that children who are born with a low birth weight are much more likely to develop diseases such as type 2 diabetes and conditions such as diabetes as they get older.

The key, as ever, seems to be moderation - which can be difficult to maintain.

Points to think about which may be asked at medical school interviews

What advice would you give a mother who was worried about eating the right sorts of foods while pregnant?

Are there any foods that are prohibited during pregnancy and if so, why?