People trying to lose weight may swear by specific diet plans calling for strict proportions of fat, carbs and protein, but where the calories come from may not matter as much as simply cutting back on them, according to a study.

Researchers whose results were published in the American Journal of Clinical Nutrition found there were no differences in weight loss or the reduction of fat between four diets with different proportions of fat, carbohydrates and protein.

"The major predictor for weight loss was 'adherence'. Those participants who adhered better, lost more weight than those who did not," said George Bray, at Pennington Biomedical Research Center in Baton Rouge, Louisiana, who worked on the study.

Earlier research had found that certain diets -- in particular, those with very low carbohydrates -- worked better than others, Bray told Reuters Health in an email, but there had been no consensus among scientists.

Bray and his colleagues randomly assigned several hundred overweight or obese people to one of four diets: average protein, low fat and higher carbs; high protein, low fat and higher carbs; average protein, high fat and lower carbs; or high protein, high fat and lower carbs.