Although dieting has been shown repeatedly to be destructive, counter-productive and useless in most settings (i.e. you re-gain everything you lose and then some…), it simply will not die as a panacea for improving health. The belief in weight loss/dieting and exercise as a health tool is so entrenched that people, even highly educated people, continue to insist that the emperor does have clothes, despite all evidence to the contrary.
I was happily reading over-due emails this early morning when I stumbled across the Med Page “breaking news” alert: “ADA: Lifestyle Changes Don't Protect Diabetic Heart”. The article was reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco.
I had to force myself to read it and, sure enough, it was a classical attempt to explain away the evidence the authors of the study themselves had accumulated. And why? Because no one could really believe that diet and exercise were useless even after follow-up for a median of more than 9 years. The diet and exercise intervention (‘lifestyle changes”) was finally halted because it didn’t work. Diet and exercise did not protect participants with type 2 diabetes against heart disease.
And why does this matter to us eating disorder types? Firstly, the bad effect of entrenched beliefs about food intake and weight loss affects interpretation of lots of research and, secondly, we find ourselves in the midst of an epidemic of type 2 diabetes and not just among “fat people.”
To explain away this apparent failure of diet and exercise there were several sleight-of-hand talking points, including the authors postulating that the reason it “didn’t work” was because the non-intervention control group (i.e. those who did not engage in diet and exercise) took more cardio-protective drugs and this might have made their results better than they might otherwise have been... Hel-lo! If cardio-protective drugs work and diet/exercise doesn’t, guess which one we should be doing!?
So what happened to the folks who dieted, the “intervention group” in the study? Their heart health wasn’t improved, apparently, but how about their waistlines? “Wing and colleagues saw greater weight loss in the intervention group than among controls at one year (8.6% versus 0.7%) but that gap started to close toward the end of the study given that initial weight loss was followed by weight regain through year five and, thereafter, a subsequent gradual drop in weight (6% versus 3.5%).”
Ok. But then how about those who did not diet and exercise, the “control” folks? What happened to their weight? “Control patients had gradual but consistent weight loss throughout the study.” This annoying finding was glossed over without further analysis or commentary.
The final paragraphs were almost comically, but predictably, titled “Study Did Show Other Benefits”. There followed by a confusing litany of “effects” some of which had no reported p value. For example they reported: “3.1% difference between overall health-related quality of life between groups over the course of the study, but mental health-related quality of life was not different between the two.” And they reported a “20% lower risk of depression over the trial period for participants in the lifestyle group” but also that “there were no differences between groups in the incidence of use of antidepressants.” Huh?
In case all these findings make you doubt the efficacy of dieting and exercise on heart health if you are obese and have type 2 diabetes (or fear you may one day do so), how about the money argument? They reported “an annual savings of $278 per year and a $2,487 savings in discounted dollars over 10 years.”
Now that’s what I call modest.