You are here

Will Yo-Yo Dieting Wreck Your Metabolism?


Over the years, many of my clients have told me they believe they’ve permanently slowed their metabolisms by repeatedly going on and off diets. In my experience mending metabolism is never a lost cause, but it does take consistency (more on this below). And now a new study, published in the journal Metabolism, confirms that a history of yo-yo dieting does not impact the body’s ability to lose weight.

The study looked at data from over 400 overweight or obese, sedentary women, between the ages of 50 and 75. The ladies were randomly assigned to one of four groups: a reduced calorie diet only; exercise only (brisk walking); a reduced calorie diet plus exercise; and a control group (no intervention). After one year the diet only and diet plus exercise groups lost an average of 10 percent of their starting body weights, so a woman in that group who started at 175 pounds ended the study at about 157 pounds.

Researchers then analyzed the data to determine if the women with a history of moderate or severe yo-yo dieting lost fewer pounds. Among the entire group 18 percent met the criteria for severe weight cycling, which is defined as having lost 20 or more pounds on three or more occasions. Twenty four percent qualified as moderate weight cyclers, meaning they lost 10 or more pounds on three or more occasions. While the severe weight cyclers weighed an average of 20 pounds more than the women with no history of yo-yo dieting, there were no significant differences in their ability to lose weight, including the percentage of body fat lost. In addition, the researchers didn’t find differences in levels of hunger hormones and insulin sensitivity between yo-yo dieters and non-weight cyclers.

So what’s the take-away? My conclusion is two fold. First, if you’ve repeatedly lost and gained weight this study confirms that you can be successful, so don’t give up. But the data also indicate a link between severe weight cycling and obesity. So if you’ve been riding the diet rollercoaster I hope this study will help you end the chaos. In my private practice there are three key strategies I work on with my clients to end weight cycling for good:

Establish Regular Meal Times
Your body loves consistency, whether it’s sleep, hydration, exercise, or eating. Establishing regular patterns helps every system in your body maintain better balance. I recommend eating breakfast within an hour of waking up and eating your remaining meals no sooner than three and no more than five hours apart. In addition to helping to regulate hunger and metabolism this consistency just makes sense based on how your body works, because you’ll give your cells a steady supply of raw materials for fuel, healing, and repair. Irregular eating can result in lacking fuel when your body needs it, or winding up with a surplus that gets socked away in your fat cells.

Create Structure With Flexibility
In my newest book S.A.S.S! Yourself Slim I wanted to create an eating plan that lays out what to eat, why, how much, and when, that also allows for a lot of customization and feels sustainable. Rather than counting calories, points, or grams, each meal is put together as a puzzle using portion-specific amounts of five puzzle pieces: produce; whole grain; lean protein (including vegan, vegetarian, and omnivore options); plant-based fat; and natural seasonings. Once you know what the five puzzle pieces are, and how much of each one to include, you can build your own puzzle meals, or customize any of the 100 meals in the book using what I call the 'great swap out rule.' For example, if a meal calls for whole-wheat pasta and you follow a gluten-free diet, you can swap the pasta for quinoa or wild rice. If a meal calls for chicken and you’re vegetarian or vegan, swap the chicken for lentils or tofu. My goal was to provide concrete “rules” for how to put meal together that result in weight loss, without trapping you in “diet prison." In my 15 years of counseling clients, I’ve seen that too-strict plans typically result in giving up, followed by rebound overeating, so finding a middle ground is key.

Plan Your Splurges
Nobody can go through life, including me, without enjoying some splurges. And you can indulge on occasion and still lose weight or maintain your weight loss results. The trick is planning your splurge in advance, rather than giving into impulsive emotional or social eating. Identifying the latter as it’s happening, and not falling into the trap of spontaneous eating is a process, but it can be done. That freedom can allow you to enjoy planned splurges while still staying in balance (check out my previous post about how to splurge on a healthy diet here).

What’s your take on this topic? If you’ve been a weight cycler what keeps you stuck in this pattern, or how have you been able to break it? Please tweet @cynthiasass and @Shape_Magazine!

Cynthia Sass is a registered dietitian with master's degrees in both nutrition science and public health. Frequently seen on national TV, she's a SHAPE contributing editor and nutrition consultant to the New York Rangers and Tampa Bay Rays. Her latest New York Times best seller is S.A.S.S! Yourself Slim: Conquer Cravings, Drop Pounds and Lose Inches.


Add a comment