The Truth About Yo-Yo Dieting

Does yo-yo dieting really make it harder to lose weight? Let’s put some scientific facts on the table and look at how you can break this vicious cycle.

The “Messed Up Metabolism”

I recently came across an article in the UK’s Daily Mail, that institution of serious journalism, portraying a woman who over 45 years lost a total of 378 lbs, yet ended up 140 lbs heavier than at the beginning.

45 years and nothing to show for. If the Mail is correct, she has been dieting since she was 15 and never managed to keep her goal weight. A pretty depressing story, for which common wisdom about weight cycling has a simple explanation.

“Ah yes,” you’ll hear, “she totally messed up her metabolism. Every time you lose weight and gain it back, the next round of getting rid of the fat becomes more difficult.”

Does It Really Become More Difficult?

To get the truth about this I searched the usual medical databases for studies examining the effect and found quite a number. None reported a connection. Here are three examples:

• Researchers at Yale University examined data from people who went to four medical exams in the span of six years. Among men there was no difference in weight gain between yo-yo dieters and others, for women it was so small that it may have been a statistical glitch (PDF).
• A UCLA study examined about 2,500 obese persons enrolled in a diet program, with some already participating for the fourth time. There was no difference in weight loss between the “repeated offenders” and the first time participants.
• A Dutch study examined obese persons via MRI scans before and after they had lost weight and then after regaining it. The results showed that losing and regaining weight does not lead to getting fatter than before or more fat being stored on the abdomen (PDF).

So Why Does It Seem Harder?

Yet I talked with people who have gone through the cycle more than once and many reported they found it more difficult each round. And it actually is.

This, however, has nothing to do with the weight becoming more stubborn. It is their minds working against them, because they embarked on a task that is truly Sisyphean.

That adjective comes to us from the Greek myth of King Sisyphus of Ephyra, who believed himself to be better than the gods. Zeus, only having a very limited sense of humor, as punishment made him roll a huge boulder up a steep hill. Whenever Sisyphus was about to reach the top, the boulder rolled back down and he had to start from the beginning.

It’s exactly the position many repeat dieters find themselves in: why attempt something yet again that experience taught you will be futile? After every weight regain the motivation of going on another round is harder to muster and maintain.

How To Break The Cycle

Let’s go back to the Mail article from the beginning. “Starvation is what it takes for me to be thin,” it quotes a second woman, and therein lies the crux: weight reduction is simply a question of burning more calories than you eat. Many people achieve it on crash diets. But sustainable weight reduction is different.

To keep your new weight, you need to understand your eating habits and change for the long haul. To go on a diet always implies that you will go off a diet. If that off means going back to eating as before, the weight will be back.

Picture courtesy of Enrique Calabuig.