Finally – there’s a verdict in the battle of low-fat vs low-carb diets. Compelling new evidence from a year-long study has helped settle the case, says registered dietitian Jennifer Low

The ‘which is the best diet for weight loss?’ has been a long-running debate, with strongly opinionated experts in each camp. But now the jury, in the form of a year-long study, has found there really is very little difference between the two diets when it comes to how much weight you lose.

The recently published DIETFITS study randomly assigned more than 600 people to either a low-carb or a low-fat diet. It also looked at people’s genetics and their insulin sensitivity to see if either had an impact on weight loss.

Both groups had access to a registered dietitian throughout the year and were given advice about how to reduce their intakes of added sugars and junk foods, while being encouraged to eat more vegetables and cook nutrient-dense healthy meals.

carb

What were the results?
After 12 months, the low-fat group had lost 11.7lb (5.3kg) and the low-carb group 13.2lb (6kg); this difference of 1.5lb over 12 months is neither statistically significant nor clinically relevant to favour one diet over the other.

Genetics and insulin production had no effect on the weight-loss results for the low-carb or the low-fat group. The study authors did say that both areas should be investigated further – there might be other genotypes or other insulin markers that do affect weight-loss outcomes.

So what can we conclude?
If you want to lose weight, you should choose a diet that’s sustainable for you in the long-term, which you enjoy and which allows you to maintain a healthy weight and achieve a healthy balance in life.

Regardless of the proportion of fat or carbohydrate in your diet, if energy in is less than energy out, you will lose weight. But a healthy, nutrient-rich diet is always the best choice, so increase wholegrains and vegetables and reduce foods containing added sugar and trans fats.

If you need help to find the right eating plan for you have a look at www.freelancedietitians.org to find a dietitian in private practice. Or ask your GP for a referral to an NHS dietitian.