People continue to be confused about whether a low carbohydrate, high fat, and high protein diet or high carbohydrate, low fat and moderate protein diet is most effective in aiding weight loss and continued weight maintenance.??

A large study last week published in the New England Journal of Medicine (Volume 360(9), pages 859-873) helps to clear up some of the?confusion. Harvard University and Louisiana State University researchers conducted a very ambitious trial, recruiting 811 midlife women and men (average age just over 50) to participate in the trial. All of the study volunteers had to be overweight or obese. The volunteers were randomized to one of four different diets:

1. 20% fat, 15% protein, 65% carbohydrate?

2. 20% fat, 25% protein, 45% carbohydrate?

3. 40% fat, 15% protein, 45% carbohydrate

?4. 40% fat, 25% protein, 35% carbohydrate??

All of the diets were designed to be heart healthy. They contained a healthy amount of dietary fiber and none of the diets contained over 8% saturated fat. All of the study volunteers were given individual counseling and group counseling over two years.??

The results of the study demonstrated that it did NOT matter what diet the person was on; what mattered was whether the person stuck with the diet. Men and women in both groups lost weight and there was no difference between groups. They lost the most amount of weight during the first six months (average 19 pounds), but still were able to keep an average 8 pounds or so off after two years. The greatest weight loss was seen in the individuals who participated in the group and individual sessions the most. All of the diets also improved lipid-related risk factors and fasting insulin levels, thereby reducing overall risk of heart disease, diabetes, and metabolic syndrome. What is also interesting is that satiety, hunger and general satisfaction with the diets did not differ between groups either.??

This study shows us that it doesn't matter what type of diet you go on...what matters is the calorie reduction! One of the other important messages from this study was that ALL of the diets were designed to be heart healthy regardless of the macro-nutrient content. Saturated fat was kept low and dietary fiber was above average.??

Bottom line here is that calorie restriction is what matters for weight loss.