People who have problems sticking to their weight-loss regime may benefit from having their genes tested, according to a recent US study.

The researchers have found a way of looking a people's genes that seems to determine what kind of diet would benefit them most.

The three diets the researchers looked at included low-fat diets, low-carb diets, and more balanced diets.

The differences were strongest in people who were trying to follow the lowest carbohydrate and the lowest fat diets.

Where low-carb and low-fat diets were concerned, people whose genetic backgrounds matched their diets lost 6.8% of their body weight in the course of the study, compared with a weight loss of just 1.4% in people whose diets did not match their genetic predispositions.

For the purposes of the study, the researchers looked at 140 women who were either overweight or obese, and randomly assigned them to one of four diets.

Some of the women were put on the Atkins diet, which is based on a low carbohydrate intake.

Others were assigned to the Ornish diet, which is extremely low in fat, or to the LEARN diet, which is also very low in fat.

The fourth diet was the Zone diet, which focuses on balance.

The researchers had some suppositions about which genes affect diet, and looked for mutations in three genes, FABP2, PPARG, and ADRB2.

After recording the amount of weight loss experienced by the women who dieted, the researchers made DNA tests on the study subjects.

Researcher Mindy Dopler Nelson of Stanford University said that, out of hundreds of genes linked to obesity, fatty acid binding protein 2 (FABP2), peroxisome proliferators activated receptor gamma (PPARG), and beta 2 adrenergic receptor (ADRB2) linked diet and weight loss.

The researchers said that study subjects whose diets matched their genetic predisposition lost 5.3% of their body weight on average, compared to people whose diets were not similarly matched.

Overall, people whose diets did not match their genes experienced only a 2.3% average weight loss over the course of the study.

Researcher Christopher Gardner of Stanford University in California said that the potential link between diet and genetics was important in helping to solve one of society's most pervasive problems.

Christine Williams, a professor at the University of Reading, said that she believed the study was very intriguing, and that it appeared to fit in well with some of her own studies.

She said that some of her research had shown certain genotypes were more responsive than others to certain types of fats such as omega-3 fatty acids.