Low-carb vs low-fat? It’s a tie, so just eat less instead
TRENDY low-carbohydrate diets are no more effective than the traditional low-fat diet, scientists have said.
A new study involving more than 600 overweight adults found both worked similarly well if adhered to strictly for a year.
Dieting strategies that focus on carbohydrates have come into vogue in recent years and have won the backing of celebrities from Jennifer Aniston to Mick Jagger. However, experts said last night that the research showed the key to losing weight was simply eating less.
The study by the University of Stanford, California, found that after 21 months participants on both the low carbohydrate and low fat diets had each lost an average of 13lb.
But the results revealed massive variations with participants losing up to 60lb in a year while others actually gained weight.
Prof Christopher Gardner, the study lead author, said the findings might dismay “those who chose sides in the lowfat versus low-carb diet debate”.
He said the study showed the fundamental strategy for getting in shape with either a low-fat or carbohydrate approach should be similar.
Namely eating less sugar and refined flour and as many vegetables as possible, while prioritising whole foods – foods that have been processed and refined as little as possible before being eaten. “On both sides, we heard from people who had lost the most weight that we had helped them change their relationship to food, and that now they were more thoughtful about how they ate,” said Prof Gardner.
The researchers also found no link between a person’s individual genetic make-up – or their insulin secretion level – and how much weight they lost.
Previous research has suggested variations in these could make it easier for some to slim down, depending on the kind of diet they adopt. The study, published in the Journal of the American Medical Association, analysed 609 men and women aged 18 to 50 who were randomly split into two dietary groups – low-carbohydrate or low-fat – and followed for a year.
Prof Gardner said this allowed the “strongest inferences” to be made from each intervention, with neither option superior.
He said: “We have all heard stories of a friend who went on one diet – it worked great – and then another friend tried the same diet and it didn’t work at all. It is because we are all very different and we are just starting to understand the reasons for this diversity.
“Maybe we should not be asking what is the best diet, but what is the best diet for whom?”
Tam Fry, from the National Obesity forum, a UK campaign group, said: “It is refreshing to see Prof Gardner’s honesty after his year of toil. The best diet in town is not a fad but much less of what you actually fancy and stick to it.”