Diets in the News: Is Low Carb Best?

Believe it or not, it isn’t my goal to turn this blog into a forum about diet and weight. But, sometimes media reports about research related to diet and weight issues make me want to whack my head on the wall. :)

Recently, a study in the New England Journal of Medicine has been in the news. Reports claim that the study demonstrated that low carb diets are better than low fat diets for weight loss. This is a very simplistic interpretation of the results of the study. Full text of the study as published is available from the New England Journal of Medicine in both an HTML version and a PDF version if you want to read it in it’s entirety. Briefly, here are a few issues to keep in mind when you consider the results of this study:

1. The study was funded in part by the Adkins Research Foundation.

2. The vast majority of participants were men, so the results have limited applicability to women, especially since there was a significant interaction between gender and the diet.

3. All of the participants were in the BMI classification of obese, so the results have limited applicability to people looking to loose smaller amounts of weight.

4. There is no control group, so the validity of assuming any outcomes are the result of any of the experimental groups is questionable.

5. After two years and remarkable compliance with the various diet programs the average weight loss in the “best” results group (low carb) was about 12lbs versus about 7lbs for the low fat group. That is about a 4lb difference in two years. I don’t know about you, but my weight can fluctuate by 4lbs in a single day.

6. That means the average weight loss was less than a pound a month. Let me say that again…. average weight loss was less than a pound a month. Even though both the low fat and low carb groups reduced their caloric intake by an average of 500 calories a day. That is an average of 3500 calories a week. There are 3500 calories in a pound. So, if weight loss really is as simple as the “calories in/ calories out” mantra that we hear so frequently shouldn’t the participants have lost an average of 1 lb a week? Hmm….I guess the human body isn’t quite that simple.

7. What I have noted above are only a few of the issues that make the results of this study far less simple than “low carb diets are better”.


Junkfood Science has a good discussion of the study posted if you want to check it out.