6 Scary Things That Can Happen to Your Body When You Yo-Yo Diet
Gaining and losing weight can have some harmful health effects—here's what you should know.
While losing weight can help trigger improvements in blood pressure, cholesterol levels, glucose management and reduce your risk for heart disease, diabetes and other lifestyle-related conditions, the process needs to be gradual and the result of long-term lifestyle changes. Often, though, consumers want quick results and will go the route of a restrictive diet, which can lead to weight loss. But it's not a weight loss that can be maintained and instead sets the stage for repeated cycles of loss and gain or what the medical world refers to as weight cycling or "yo-yo dieting."
Yo-yo-ing up and down in body weight tends to be more common than successfully maintaining weight loss, and it results from trendy diets and restrictive eating plans. Watching the scale go up and down can leave you with closet of clothes ranging in size, but also frustrated and worn out when it comes to improving health. And it turns out that the effects may not end there. In addition to the psychological toll, research suggests that periodically losing and gaining weight may increase one's risk for heart disease, diabetes, gallstones, cancer, osteoporosis and even dementia.
Here are six ways—beyond the scale—that yo-yo dieting may impact your health long-term.
Increased Body Fat
Most all who "go on a diet" are looking to decrease their body fat. And even if you gain weight back a year later, it would seem that you'd just be right back where you started in terms body fat. But this doesn't seem to be the case, because several rounds of losing and gaining weight is actually associated with having a higher BMI, a higher body fat percentage and greater likelihood of storing fat around the midsection. In fact, women who reported yo-yo dieting (losing and then regaining at least 10 lbs at least once) were 82% less likely to be at a healthy BMI according to data from the American Heart Association. Also, repeated episodes of yo-yo dieting appears to lead to greater body fat accumulation in the midsection, which poses a greater risk to health than fat in the lower body.
Getting closer to a healthy body weight is one of the best ways to improve glucose management and to reduce your diabetes risk. However, there's also significant research to suggest that losing weight only to then gain it back may increase diabetes risk. In 2014, research published in Diabetes Care found that the frequency of yo-yo-dieting cycles (in this case, a loss and then re-gain of a minimum of 5 pounds) was a significant predictor of diabetes risk and that yo-yo dieting as a whole increased diabetes risk. A 2019 article had similar results suggesting that regular fluctuations in body weight due to dieting was a risk factor for diabetes.
Losing weight to reach a healthier body weight is associated with reducing one's risk of most all heart-related conditions from high blood pressure to stroke to heart attack, but what happens when weight is repeatedly lost and gained? The American Heart Association data mentioned earlier suggests that the more times a woman reported yo-yo dieting, the poorer her heart health based on the AHA's Life's Simple 7 tool. In fact, women who reported yo-yo dieting at least once were 51% less likely to have a moderate heart health score and 65% less likely to have an optimal score. And this supports findings published in 2017 suggesting that individuals who had the greatest fluctuations in body weight had a 85% greater risk of having some type of heart event, 117% greater risk for heart attack and a 136% greater risk for stroke.
Frequent yo-yo dieting episodes where weight is lost and then regained appears to increase risk for gallstones in both men and women. Some research suggests this risk increases with greater range in weight fluctuations and frequency of dieting episodes.
A 2013 study from the American Academy of Neurology suggested that weight fluctuations may increase risk of dementia later in life and that the overall risk for dementia increased, depending on how great those weight changes were.
Yo-yo dieting may decrease bone density according to a 2015 study. The problem stems from the loss of lean body mass (along with fat mass) during weight loss. Lean body mass is associated with good bone health, a key reason why exercise is encouraged for bone health. However, when weight is regained, that weight is added back primarily as fat mass, leading to an overall decrease in lean body mass than before weight loss.
The Bottom Line
Most health professionals are quick to still advocate getting closer to a healthy BMI or body fat percentage to improve health and reduce disease risks. To increase the likelihood that the loss can be sustained, it's essential to do this at a slow, healthy rate (0.5 to 2 pounds per week) through small changes in diet, activity and lifestyle, not through restrictive diets.
Carolyn Williams, PhD, RD, is author to the new cookbook, Meals That Heal: 100+ Everyday Anti-Inflammatory Recipes in 30 Minutes or Less, and a culinary nutrition expert known for ability to simplify food and nutrition information. She received a 2017 James Beard Journalism award. You can follow her on Instagram @realfoodreallife_rd or on carolynwilliamsrd.com.