Dieters frequently report reaching their goal weight, only to find that the pounds creep back on.

Scientists say the trick to keeping weight off permanently is to cut 300 calories from your daily food intake.

In a study presented at the European Congress on Obesity earlier this year, Professor Michael Rosenbaum described how dieters need to consume 22% fewer calories a day than someone who hasn’t dieted simply to maintain their weight (so a non-dieter could consume 1,600 calories a day and not gain weight, while a dieter of the same weight must stick to around 1,300).

Scientists say the trick to keeping weight off permanently is to cut 300 calories from your daily food intake

Dietitian Linia Patel, spokesperson for the British Dietetic Association, says: “It’s believed this phenomenon can be explained by the effect dieting has on muscles. Dieters’ muscles need fewer calories to do the same work than those of people who haven’t been on the diet in the first place.”

As we age the picture becomes even bleaker.

“Lean muscle helps the body burn a greater number of calories, but as we age our muscle mass drops along with our metabolism.”

The result is that our bodies need fewer calories to maintain our weight.

But extra calories can be burnt off through exercise – resistance training and lifting weights are among the most effective ways to build lean muscle mass.