Fat, Carbs, and Protein: How To Balance Them To Achieve Weight Loss

If you are feeling somewhat confused about the many diets, supplements, and plans to lose weight, you aren’t alone. You probably know that you need to consider the best way to divide up your food intake between fat, carbohydrates, and protein, but how should you do it?

Until recently, there weren’t any studies that compared different plans in a way that really compared apples to apples (please excuse the dietary metaphor). There were also no studies that concentrated on how to keep pounds off after the initial thrill of losing them. In fact, different studies reported different results – but no studies worked on precisely the same criteria!

Fortunately for those of us who could stand to lose some extra pounds, distinguished doctors and scientists from various U.S. universities, medical schools, and research centers collaborated in a 2009 study published by the New England Journal of Medicine to find the answers. They decided to divide the subjects of this experiment between four groups with diets with different percentages of calories from fat, protein, and carbs:

• High fat, average protein – 40% fat, 15% protein, 45% carbohydrates
• High fat, high protein – 40% fat, 25% protein, 35% carbohydrates
• Low fat, average protein – 20% fat, 15% protein, 65% carbohydrates
• Low fat, high protein – 20% fat, 25% protein, 55% carbohydrates

For example, a diet of high fat and average protein would get 40% of its calories from fat, 15% from protein, and 45% from carbohydrates.

All diets included similar foods, and all of them were carefully composed to be healthy for the subjects’ hearts. In addition, those in the study were given the chance to receive individual and group education on their diets. Because waist circumference has been shown to be a factor in heart disease, the study also carefully monitored whether the participants’ waistlines decreased or not.

In order to test the four diet groups effectively, the participating scientists found 811 overweight adults and divided them as equally as possible between the four groups. About 80% of the study’s subjects finished the study to completion.

After six months, those in the study had lost an average of 6 kilograms, or about 14 pounds! Unfortunately, they held this weight loss for only six more months and then started gaining their weight back. After two years, they had kept off only part of the weight – generally about 7 pounds each.

We know you’re anxious to hear – what ingredient is most important to reduce so that you can lose weight? Well, it turns out this study showed that it doesn’t matter whether fats, protein, or carbohydrates have high or low percentages in a diet. Only two things really mattered to participant success: reducing calories and attending group meetings. Both weight loss and waistline measurements were similar for the study subjects no matter what group they were in.

Also, every group session attended led to almost half a pound in weight loss.

So no more fussing about fat, carbs, and protein. Reduce your calories and find a support group, and your weight will drop!


NEngl J Med 2009; 360; 859-73

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