Sunday, March 1, 2009

Can You Trust the Media on a Weight Loss Study? Not Really.

I'm annoyed with a report from the Associated Press that lured me in with a false headline: "Low-fat, low-carb or high-protein? The kind of diet doesn't matter." It purports to summarize a New England Journal of Medicine study.

Yet as I read the report, it was obvious that it did not really compare low-fat, low-carb or high-protein diets, at least not what most of us believe those terms mean. Anyone who has tried the Atkins diet knows what low-carb really involves and it does not allow the "healthful grains" that all participants in the study ate daily.

So don't believe the AP headline, it is just hype! Read the actual report if you want, or just save time and read the NEJM Editorial. It points out that
  • The dietary goals were only partly achieved.
  • After 12 months, subjects started to regain weight.
  • Although the participants were highly motivated and intelligent AND were coached by expert professionals, they did not achieve the weight losses needed to reverse the obesity epidemic.
  • We do not need another diet trial; we need a change of paradigm; ie, ways to encourage exercise.
Sounds like what the study really shows is that it's hard to keep weight off by dieting!

For those that believe that "different" diets were used, read this from the NEJM report: The four diets also allowed for a dose–response test of carbohydrate intake that ranged from 35 to 65% of energy. Other goals for all groups were that the diets should include 8% or less of saturated fat, at least 20 g of dietary fiber per day, and 150 mg or less of cholesterol per 1000 kcal. Carbohydrate-rich foods with a low glycemic index were recommended in each diet.

You can download a PDF of the actual plan. Actual meal plans are included. NONE OF THEM CLAIMS TO BE LOW-CARB, although two are High Protein. All four diets include bagel, egg, and milk for breakfast, but with different serving sizes. DUH! It's basically the same diet, just varying whether you can eat half a bagel or a full one, etc.

I don't blame the medical guys for the false headline, it is the fault of AP reporter Alice Chang or her editor. Unfortunately she continues the misinformation throughout the report .

Never trust the media on science or medical reports; always go to the source or look it up on Google Scholar or Unbound Medicine.