Everyone knows that a low calorie diet can help people lose weight, but what is the secret to keeping it off?

At least part of the answer is regular fitness training, according to a new study published in the research journal Obesity.

Personal trainer Rich Leigh advises that through healthy eating and exercise most people can expect to lose between two and four pounds a week.

In addition, recent research has found women who lost weight through dieting gained less weight in the subsequent year if they stuck with either an 80-minutes-per-week aerobic fitness training or resistance-exercise programme than if they did no physical activity.

Women lost an average of 27 pounds during the weight-loss phase of the study and returned for follow-up evaluation 12 months later.

At the one-year follow-up, the women who stuck to an exercise programme had gained back an average of about seven to nine pounds, whereas those who did no exercise gained back on average more than 13 pounds.