Why Lost Pounds Return and Bring Friends

An acquaintance once said that she had lost over 200 pounds. Looking at her girth, I confess that I doubted the claim until she quickly added, "Of course, it's the same 20 pounds 10 times."

Given the single-minded focus required to lose weight, why do so many of us (an estimated percent) regain the pounds we lost-and even add a few more? How maddening is that?

Researchers are starting to explain this common experience, and their insights are both encouraging and discouraging.

On the positive side, long-term weight loss is possible, and some individuals are able to maintain their reduced weight. The National Weight Control Registry is currently tracking over 10,000 individuals who have lost 30 or more pounds and who have maintained the lower weight for one year or longer. On average, registry members have lost 66 pounds and have maintained their lower weight for over five years.

The weight-loss stories vary. Some registrants lost 30 pounds; others, 300 pounds. Some lost weight rapidly; others, slowly. Slightly less than half the registrants lost weight on their own; just over half participated in a program.

However varied their approach, successful losers in the National Weight Control Registry are bucking the odds as well as their body's metabolic efforts to restore homeostasis, a fancy term for "returning to the former status quo of a heavyweight."

I say that successful losers are beating the odds because weight loss seems to trigger changes in physiology that make regaining weight difficult to avoid.

In a yearlong study, Australian researchers studied the hormonal changes of 50 overweight or obese individuals, and the results appeared in the October 26, 2011, issue of the New England Journal of Medicine.

Researchers found that as patients began to lose weight during the eight-week weight-loss program, hormones that triggered appetite increased, while hormones that regulated metabolism decreased. In effect, the patients' bodies were saying, "Eat more because you are starving me. In the meantime, I'll conserve what energy I have."

This reaction seems predictable enough, but what followed was surprising.

After the weight-loss period ended and the weight-maintenance phase began, the hormonal changes continued. The circulating levels of hormones increasing appetite and slowing metabolism continued even after the weight was regained. In other words, losing weight seemed to permanently dial up the appetite and dial down metabolism-the worst of both worlds.

The study ended leaving one key question unanswered-do the hormonal changes ever return to pre-weight-loss levels? Or do the changes represent an irreversible shift in the body's physiology?

However discouraging the findings, documenting this phenomenon explains the impact of yo-yo dieting, where weight loss is followed by weight gain greater than the original amount lost.

These results also confirm the conclusions of researchers at the University of California, Los Angeles, who analyzed 31 long-term diet studies and found that "about two-thirds of dieters regained more weight within four or five years than they initially lost."

In addition, these insights are consistent with a recent finding by Brown University researchers. The study reported the discovery of molecular changes in the brains of rats whose obesity was diet induced that simultaneously increased appetite and reduced the expenditure of calories. Put simply, the researchers concluded that obesity begets obesity.

So what should a reasonable person conclude from these insights? My strategy is to forget dieting and instead focus on fitness.
Eating a healthy diet based on whole grains, fruit, vegetables, chicken, fish, low-fat dairy products and minimal amounts of beef, sugar and refined food is half of my program. The other half is regular exercise-particularly walking. My goal is to accumulate 10,000 steps or more each day.

I'm also practicing kindness-toward myself when my efforts to live healthfully break down and toward others who are similarly struggling to get fit. What's your strategy?

Photo courtesy of  Sinona Karen on Flickr.