For losing weight and lowering heart disease risk, a low-carbohydrate diet may work better than low-fat, a new study found. In this study, people on a low-carb diet reduced certain risk factors for cardiovascular disease and lost nearly three times as much weight as those on a low-fat diet.
The people in the low-carb group were advised to eat less than 40 grams of digestible carbohydrate per day, and those in the low-fat group were told to get less than 30% of their daily calories from fat (less than 7% from saturated fat) and 55% from carbohydrate. Neither group got a limit for total caloric intake. Participants were told not to make changes to their current activity level. At the end of the study period, participants in the low-carb group had lost nearly 12 pounds on average. Those in the low-fat group had lost only 4 pounds on average.
However, despite the seemingly straight-forward implications of the findings, headlines in the news such as “Low Carb Beats Low Fat” sparked some debate. Many felt that the headlines were overdramatic and misleading. In an interview with several health care providers, concerns were voiced over the oversimplifications of the study’s results.
In the interview, Dr. David L. Katz, director, Yale University Prevention Research Center, and author of “Disease Proof” said that this was not a true low-fat vs low-carb study:
If this had been a study of low-fat versus low-carb diets, it would have been silly and archaic. The wholesale cutting of these macronutrient classes without regard for the foods involved is discredited nonsense. Cutting ‘carbs’ would mean cutting vegetables and fruits; cutting ‘fat’ would mean cutting nuts, seeds, and avocado. These are not sensible practices. He added that the study compared a low-carb diet with a minimally fat-reduced diet. Participants randomized to the low-carb group were asked to cut their carbohydrate intake by about 75% from baseline; those in the so-called low-fat group, a paltry 5% from their baseline. The much more restrictive low-carb diet wound up being considerably lower in calories throughout the study — and for that reason participants in that group lost more weight. All of the participants were obese at baseline and had impaired cardiac risk measures because of obesity — so those who lost more weight had more improvement in cardiac risk for that reason.
As Katz hinted at, critics of the headlines believe that they may mislead people to cut certain food groups altogether, including healthy carb choices such as fruits and vegetables. The findings don’t call for completely abandoning all forms of carbs, nor as lead study author Dr. Lydia Bazzano cautioned, “suggest that we hit the butter and meat fats. But the findings do suggest that even very high-fat diets can be healthy.”
Dr. Val Andrei, expert weight loss surgeon in New Jersey, agrees with Dr. Katz’s view on the broad over-generalization of the terms ‘carbohydrates’ and ‘fats’. He said, “Simple carbohydrates, those made from white flour products, should be reduced for weight loss, while fruits and vegetables should be eaten without limitation since they are high in nutrients and fiber. Monounsaturated fats, such as those from nuts and avocado and olive oil, can be very satiating and help people eat less volume. Omitting entire food groups may work for a short time but often causes diet fatigue and subsequent weight regain.”
As confusing as information as weight loss is, it’s important to remember that the headlines can be as confusing as the information itself.
Related Reading: Study Shows Cutting Carbs May Cut Body Fat