A New England Journal of Medicine study published today examined how 811 people fared on four different diets with varying macronutrient contents:
1) 20% fat, 15% protein, 65% carbohydrate
2) 20% fat, 25% protein, 55% carbohydrate
3) 40% fat, 15% protein, 45% carbohydrate
4) 40% fat, 25% protein, 35% carbohydrate
They were offered diet counseling and instructions for 2 years and ate similar foods on these diets. So which diet won the battle of the bulge? It was a 4-way tie. Satiety, hunger, diet satisfaction and group attendance was similar among the groups. However, the authors found one a few commonalities to other weight loss studies. First, there participants saw an initial weight loss in the beginning followed by weight regain or a plateu. This is common because in the beginning people are fired up about losing weight and over time their enthusiasm may wane. The second common finding was that the participants had a tough time following the macronutrient guidelines. This too is not surprising. First you’d have to calculate your calorie intake then keep track of your macronutrient intake to ensure you are achieving the right percentages. So, you pretty much need to keep a detailed diet record. This finding is also important because it throws off the results of the study. If you are comparing a low carbohydrate diet to a high carbohydrate diet, you better have the participants really control for carbohydrate intake.
The authors concluded (both from the published research and their own study) that diets of differing macronutrient content can be used to achieve weight loss. And, I totally agree with this. However, this study didn’t take body fat percent into account. And, weight loss doesn’t always mean fat loss. In fact, many people lose a mix of bone tissue, muscle and fat. The goal should be to minimize the loss of the first two and maximize fat loss. Doing this requires a certain amount of high quality protein in your diet.
The second conclusion they made was that diets should be tailored to individual patients on the basis of personal and cultural preferences for the greatest long term success. Now this I completey agree with. Most people aren’t going to flip through a magazine or look online and follow a meal plan exactly as it is written. Those are meant to be used as general guidelines, not diet prescriptions.
So, what’s the take-home point here? Weight loss is hard. We can get people to lose weight but keeping it off is another battle. The most successful people keep track of their weight and food intake and they exercise. They also succeed by attending group sessions or regularly seeing a dietitian to make changes to their current diet.