Monday, December 7, 2009

The Perils of Yo-Yo Dieting!

posted originally on

Face-Off: Dr. Abby Vs. Dr. “South Beach!”

In the next phase of our interview, Dr. Agatston and I discussed yo-yo dieting. My biggest concern about dieting and weight loss is the near-inevitability of gaining back weight lost. Not only is this emotionally devastating, but research strongly suggests that adverse physiological harm results from weight cycling.

Dr. Abby: Some of my patients have abused Phase 1 of The South Beach Diet by returning to it frequently and yo-yo dieting.. Can you comment about harmful effects of yo-yo dieting?

Dr. Agatston: People go for quick weight loss, and that’s the whole sense of “diet.” The idea of fast weight loss was always a concern for us. The first phase is certainly for people who are really overweight, who have insulin resistance, or are hungry all the time. It works very well if you get rid of cravings and get some good psychological feedback.

But you must move towards a lifestyle or you will yo-yo. Rapid weight loss lowers muscle mass and lowers metabolism, and it gets tougher and tougher each time. What I always say is, you can even lose weight quickly with a cabbage soup diet. However, you’d just get tired of it and go off it. You must turn the diet into a lifestyle or you will yo-yo back, and it gets tougher and tougher.

The thing with yo-yo dieting that’s not really out there, is that people who are insulin resistant are able to yo-yo easily. Fat and thin people have more trouble, since they don’t gain or lose so easily. Insulin resistant people lose cravings and lose weight rapidly. But once they go back to what they were doing, they also gain more rapidly.

People with the highest risk are able to yo-yo the most. But yo-yo dieting puts them at the highest risk the for coronary disease. For people who are able to yo-yo, it is most important not to. They need the lifestyle. The ability to yo-yo almost connects you with a high risk person, and somebody who shouldn’t yo-yo, I guess.

Dr. Abby: Wow, I’ve never quite heard it put that way! Thanks for clarifying. I was kind of going for the belly fat answer, but am glad to hear this. However, so many people who yo-yo diet add more belly fat on the way up. They’re less healthy than before losing the weight, right?

Dr. Agatston: Right! They’ve lost some muscle mass, and belly fat comes back very rapidly; usually more than before.

Dr. Abby: It has compensatory effect. The body doesn’t know when the next famine is coming, so-to-speak. And it’s useful when we’re starving but not useful when we’re not.

Dr. Agatston: Exactly.

Commentary: Many people view The South Beach Diet as a diet, and not a lifestyle. They return after regaining lost weight, and therefore yo-yo diet. Although Dr. Agatston admits that fast weight loss in Phase I can offer psychological encouragement, the great majority of people who lose weight do gain it back. Encouragement can quickly turn to discouragement. Can we eliminate Phase I and go straight to maintenance? The program Dr. Agatston implemented in some Florida schools did just that; there was no emphasis on weight loss or even portion control; just healthy choices. It is very heartening to see evolution and growth in his philosophy.

My forthcoming book, Dr. Abby’s Diet Revolution!, helps people to personalize food plans so they can stick with it forever. Incorporating “healthy junk food” can help. Learn about it in this free download of my first book, Your Final Diet.

This is part 3 of the Dr. Abby vs. "Dr. South Beach" interviews.
Check out the first two installments here: Part 1, Part 2

Dr. Abby graduated from Columbia University, and holds 2 masters degrees and a Ph.D. She is a member of the American Psychological Association and Mensa. As a psychologist in private practice for 16 years she helped people with a wide variety of concerns, and has spoken on many topics related to weight loss, mental health, parenting and relationships. Dr. Abby is also president of DAA, Inc. For information regarding coaching, speaking, or therapeutic products, please visit her website at