The study from the Johns Hopkins Medical Center also showed that those that followed a low-carb diet lost more weight than those following a low-fat diet, in fact 10 lbs. more overall, and the low-carb group lost more abdominal fat overall.
"There continue to be misperceptions about low-carbohydrate diets and many continue to think it is not a heart-healthy diet plan. This is the first study of this scope that demonstrates a significant drop in the levels of all three measures of inflammation for those that lost weight and abdominal fat, with those following a low-carbohydrate diet lost more weight and belly fat.
The Johns Hopkins study examined overweight or obese but otherwise healthy individuals between the ages of 30 and 65 years over a six-month period. One group was randomly assigned a low-carbohydrate diet and the other a low-fat diet. Exercise was included for all participants and inflammation was checked before and after six months. The low-carb group followed a low-carbohydrate type diet with initially, 15%, 30%, and 55% of calories coming from carbohydrates (CHO), protein, and fat. There was a gradual shift to a balance of 40%, 20%, and 40% of calories from CHO, protein, and fat. The low-fat diet followers had 30% of calories coming from fat, 50-55% from CHO, and 15-20% from protein.
Lead investigator, Kerry Stewart, Ed.D presented the findings at the AHA meeting and said that the findings indicated that people can reduce systemic inflammation, and possibly lower their risk of heart disease, no matter which diet they choose -- either low-carb or low-fat. Dr. Stewart is a professor of medicine at the Johns Hopkins University School of Medicine and director of clinical and research exercise physiology. His study indicated that the important factor is how much weight you lose -- especially belly fat. Those in the study that followed the low-carb diet lost more abdominal fat overall.
According to the findings, the participants on the low-carb diet lost more weight, on average, than those on the low-fat diet -- 28 pounds versus 18 pounds. The low-carb diet group also had a greater drop in BMI (4.7 versus 2.9), and a greater drop in belly fat (14.3 versus 8.4 pounds). The level of aerobic fitness increased in both groups by about 20 percent.
The researchers measured the participants' blood levels for three common markers of inflammation at the beginning and end of the study. They also measured body weight, body mass index (BMI) and total body and belly fat. At the start, both groups were similar in the various measures, including elevated levels of inflammation markers.
Results of the study were presented on November 5, 2012 at the American Heart Association Scientific Sessions.