It’s not about weight loss

There's a long-standing divide in research's approach to the issue of obesity: on the one hand, there are those who focus solely on body weight and ways to reduce that body weight to a clinically normal level, and then there are those who contend that what you eat is at least as important as how much you eat. (This might be termed, "When is a calorie a calorie?") Adding to the confusion is the problem of weight maintenance: once people lose weight, the vast majority of them gain it back, and often more than they lost. My focus, as you may have guessed if you are a regular reader, is not on weight loss - it's on improving what you eat.

A well-meaning team of researchers affiliated with the Veteran's Affairs Health Service designed a study to help those who lost weight maintain their weight loss (Ann Int Med doi.10.7326/M16-2160). At first they invited clinically obese (Body Mass Index over 30) but otherwise healthy men and women between the ages of 18 and 75 to participate in a 16-week weight loss program that focused on cutting calories and reducing the amount of fat in their diet. At the end of the program, those participants who had lost at least 4 kilograms (about 9 pounds) were invited to participate in a weight maintenance program (the study).

Half of those who accepted the invitation were assigned to a "usual care" program (the control group). After the weight loss program ended they were not contacted again until 14 weeks after the end of the weight loss program, at which time they revisited the research lab and were weighed. They were weighed again about every 4 months until the end of the study, at 56 weeks after the end of the weight loss program.

The other half of those who accepted the invitation were assigned to a "maintenance" program. In addition to the same re-weighings as the control group, two weeks after the end of the weight loss program these participants attended the first of 3 monthly group discussion sessions with a dietitian to work on weight maintenance skills. Further contact with the dietitians was by phone, for the first six months on a monthly basis, then two additional calls at month 8 and 10, with no further contact (other than the same weigh-ins as the control group) until the end of the study.

The authors make much of the fact that those receiving the phone calls maintained more of the weight they lost, with the control group regaining about 40% of the weight they lost and the maintenance group regaining about 15%, but the real difference between the two groups, on average, is only about 1.7 kilograms (about 4 pounds). That might be statistically significant, but this is a case where "statistically significant" equals "practically meaningless": weight loss should not be a goal in and of itself (yes, I really said that).

If your focus is exclusively on calories, you can certainly lose weight by eating fewer calories of junk - but you won't be healthier even if you weigh less. Rather than teaching the participants to simply reduce the number of overall calories they consumed as well as cutting fat, these participants would have been better served to have been taught how to choose higher quality calories so that they could pursue a dietary lifestyle that they could live with for the long term - rather than a "diet" they would inevitably stop following. They would be healthier even if they never lost a pound.

What this means for you

Diets don't work: lifestyle change works, and works for the long term. We're focused on meeting my patients where they live and helping them improve the quality of the calories they eat without giving up the foods they love. That's why we advocate a Mediterranean-style diet, as it can be adapted to any type of cuisine, from Asian to African, Southern United States to Napa Valley.

First posted: February 22, 2017