Exercising 'better than dieting for cutting calories' study finds

Participants in the study who exercised ate less than those who dieted

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Exercising is more effective than dieting in limiting how many calories a person eats, according to a new study.

Researchers at Loughborough University set out to investigate how exercising and restricing diet changed a woman’s physical and behavioural responses to food.

During the study, women were first asked to restrict their diet by 3,500 kilojoules, or around 836 calories, for 8 hours. They were then invited to eat freely at a buffet where researchers secretly measured what they consumed.

In the second part of the study, researchers asked the women to burn the same amount of calories they had previously cut from their diet with moderate exercise lasting 90minutes.

The women were again presented with a buffet and unknowingly monitored.

The researchers found that women ate 944 calories on average at the buffet when they restricted their diets, compared with 660 after exercising.

Limiting the amount of food caused a spike in the hunger hormone ghrelin and a drop in levels petitide YY, which supresses hunger, researchers found.

The findings of the pilot study involving 12 women contradict previous evidence which shows that exercise makes people, and particularly women, eat more.

Dr Stensel, a Reader in Exercise Metabolism in Loughborough’s School of Sport, Exercise and Health Sciences, said: “We’ve shown that exercise does not make you hungrier or encourage you to eat more - at least not in the hours immediately following it. Our next step is to see whether this benefit continues beyond the first day of exercise.”

Michael Trenell, Professor of Metabolism & Lifestyle Medicine at Newcastle University who was not involved in the study, commented: “This is a pilot study that provides an important insight into appetite regulation and exercise.

Professor Trenell went on to stress that the results relate to maintaining weight and motivation, and that exercise alone does not cause weight loss.

"The amount of exercise you need to do to loose weight is beyond most people. This study highlights the level of self motivation needed to loose weight, you are fighting physiology by eating less.”

He went on: “It is clear that a balance of diet and exercise is critical in maintaining a healthy weight. The message from this study reinforces this, showing that you can expend energy and without a large drive to replace it.

British Dietetic Association spokeswoman Claire Pettitt said that the study is small and further research is needed into the longer term effects of exercise on appetite.

“I would still recommend anyone trying to lose weight and or maintain a healthy weight and lifestyle should be mindful of both their dietary habits and physical activity levels.”

But she added that while the study is small, it is important because previous research has largely focused on men.

The evidence on exercise suppressing the diet is inconclusive, she explained, adding that some studies show that creating an energy deficit with exercise causes body fat loss in men more so than women, while others show no difference between the sexes.

This may be becomes women’s bodies are programmed to keep weight on in order for them to be able to reproduce.

Ms Pettitt highlighted: "As with many other diet and lifestyle factors, it isn’t a one-size-fits-all approach.”