Bad news for the anti-carb set: A study published Tuesday in JAMA, the Journal of the American Medical Society, reported that a healthy low-fat (HLF) and a healthy low-carbohydrate (HLC) diet can be equally effective for weight loss.
The randomized clinical trial, conducted by researchers from the Prevention Research Center, Quantitative Sciences Unit, Department of Health Research and Policy, Department of Statistics, and Department of Biomedical Data Science at Stanford University, tracked 609 overweight but diabetes-free adults, ages 18 to 50, between January 29, 2013, and April 14, 2015, with a final follow-up on May 16, 2016.
"There was no significant difference in weight change between a healthy low-fat diet vs. a healthy low-carbohydrate diet," the study concluded. The researchers also determined that — many diet books to the contrary — there was no apparent relationship between a dieter's insulin levels or genetic makeup and the type of diet that would work best for that person. In reporting on the study, however, The New York Times cited the belief of Dr. David Ludwig, a Boston Children's Hospital obesity researcher, that the study wasn't rigorous enough to definitively rule out the suitability of certain diets based on insulin levels or genotypes.
What was officially called the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) study separated participants into two groups. One was instructed to reduce total fat intake to 20 grams per day, the other total carbohydrate intake to the same amount, for a period of eight weeks. Following that, groups slowly added fats or carbs back into their diets until they reached a level they thought they could maintain indefinitely. In addition, both groups, according to the study, "were instructed to (1) maximize vegetable intake; (2) minimize intake of added sugars, refined flours, and trans fats; and (3) focus on whole foods that were minimally processed, nutrient dense, and prepared at home whenever possible."
While some participants actually gained weight during the course of the study, many lost significantly, with an average decline of 13 pounds per person.
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