Recent headlines have said the low-carb Atkins has been vindicated.
Has it? No.
A two-year Israeli diet study funded by the Atkins Foundation and reported this month in the New England Journal of Medicine randomly assigned 322 obese people – mostly men – into one of three diet groups, low-fat, Mediterranean or a low-carbohydrate diet described as being based on the Atkins weight loss plan.
Reported weight loss was greatest on the low-carb diet. Low-carb eaters also had the greatest improvement in some blood fat levels.
The study's bottom line: Low-carb and Mediterranean diets might be good alternatives to low-fat diets for people who need to lose weight.
But questions remain about key aspects of the study and what the results really mean.
Did the study really evaluate the Atkins diet?
Participants who followed the low-carb diet were counseled to “choose vegetarian sources of fat and protein.” That's at odds with the Atkins plan described in bestselling books, which suggests followers may eat large amounts of meat and cheese.
Why did participants lose so little weight?
People lost weight on all three diets, but despite intensive monitoring and coaching, participants lost an average of only 6 to 10 pounds.
Were the low-carb eaters the only ones told to avoid trans fats?
The low-carb group was counseled to avoid trans fats, but there is no mention of whether the low-fat or Mediterranean groups were. Could different intakes of trans fats help explain differences in participants' cholesterol levels?
Was the low-fat diet used in the study relevant?
According to the article, the “low-fat” group ate diets that got 30 percent of calories from fat – not very low – and their fat intake was almost unchanged from the level in their diets before the study.
Growing scientific consensus points to diets similar to a Mediterranean-style diet – high in carbohydrate-rich plant foods and low in saturated fat, trans fat, added sugars and salt, and refined foods – as being best for long-term health, including prevention of cancer and heart disease.
When obesity and diabetes rates are skyrocketing, people need clear and sound diet advice. That includes putting diet claims into perspective.