Here’s some good news for men, less so for women. Men lose weight more easily than women, something I’ve always put down to their greater muscle mass and therefore burning more calories.

The University of Edinburgh-led research team says dieting affects men and women differently when they’re young adults, although the variations disappear with age. They also found men on reduced calorie diets lost more fat than women and had greater improvements in blood sugar levels as well.

The findings suggest that oestrogen, one of the main female sex hormones, may play a role in determining the health benefits of dieting. Experts say this could help to identify those most likely to benefit from a restricted calorie diet. Reducing calorie intake is linked to the prevention of conditions such as obesity, high blood pressure, type 2 diabetes and increased life expectancy.

The researchers looked at the impact of a reduced-calorie diet on the health of both mice and human beings. The six-week study involved 96 mice whose daily calorie consumption was 30% less than normal and 85 mice on a normal diet. The team found the reduced-calorie diet lowered blood sugar by 22% in young males but only 16% in young females. The effects on body fat were even more striking – in males, fat decreased by nearly 70% but females lost no fat at all. The study found young female mice limited the breakdown of body fat, used less energy and produced fat after meals.

The international research team from the Universities of Edinburgh, Aberdeen, the Highlands and Islands, Glasgow, Taiwan and Tokyo did a small weight-loss study of 42 overweight or obese men and women which confirmed that the same age and sex-based differences occur in human beings as they did in mice.

Across four weeks, men under 45 lost more than 16% of their body fat, while women in the same age group lost only 8%. However, there was no difference in fat loss between males and females older than 45, with both sexes losing around 10% of their body fat.

“Reduced-calorie diets have many health benefits and may promote healthy ageing,” says Dr William Cawthorn, study lead at Edinburgh University. “Some previous research suggested that the effectiveness of these diets may differ between males and females, but our study is the first to show that these sex differences largely disappear when dieting begins at older ages. This could help us to devise improved nutritional strategies to prevent diseases and promote healthy ageing.”