If you’ve been attuned to the diet world for any time now, you’ve likely heard the idea that gaining weight and losing weight cyclically – often referred to as yo-yo dieting– can throw off your metabolism and cause a whole whirlwind of health problems.
Well a new study would argue that point, suggesting that yo-yo dieters fare no worse than people who remain at a constant weight when it comes to a healthy metabolism. And furthermore, they aren’t any less capable of losing weight than their non yo-yo dieting counterparts.
As reported by NBC News, to conduct the study (published in the journal Metabolism), researchers gathered nearly 400 participants, all of whom were overweight or obese pre-menopausal women between the ages of 50 and 75.
Of this group, 103 women (24 percent) had a past of moderate weight cycling, gaining and losing about 10 pounds multiple times a year. And 77 women (18 percent) had a past of severe weight cycling, meaning they lost and gained 20 pounds several times a year. At the beginning of the study, those in the moderate-to-severe weight cycling categories were heavier on average than those who did not fluctuate in weight.
Researchers assigned the women to one of four groups: diet, aerobic exercise, diet and aerobic exercise, and one control group. The diet prescribed was based on the diabetes prevention program, and required participants to stay within a 1,200 and 2,000 calorie range depending on starting weight. With this group, participants aimed to reduce overall fat intake to 30 percent of daily calories, and also encouraged plenty of fruit, vegetables and fiber. Exercise recommendations were 45 minutes a day, five times a week, three of which were with a personal trainer.
At the end of the year-long study, the yo-yo dieters surprisingly saw no significant difference in the effect of diet or exercise, body fat percentage or lean muscle mass gained or lost compared to those who hadn’t struggled with yo-yo dieting in the past.
Additionally, researchers concluded that the primary tools that enabled the women to lose weight were recording everything they ate, eating more meals at home, weighing themselves weekly, and not skipping meals.
It’s estimated that nearly 40 percent of people in “Westernized countries,” like the U.S., have a tendency to weight cycle. Up to this point, it’s been a common assumption that yo-yo dieting increases the chances of gaining weight over time. But this new research sheds some light on the validity of this claim.
“I am not surprised that yo-yo dieting doesn’t alter metabolite rate,” said DietsInReview.com’s Registered Dietitian, Mary Hartley, RD. “Research has consistently shown that weight cycling does not produce lasting metabolic changes. Since famines have been the norm since the beginning of time, it makes sense that humans and animals are wired to switch between states of near-starvation and overeating.”
Mary also noted that the study concluded that weight-cycling did not impede successful participation in a weight loss program, which makes sense as dieters know how to “diet.” And perhaps a more important factor to consider is the potential emotional effects that gaining and losing weight can have on a person.
“What wasn’t studied was the emotional toll that yo-yo dieting takes,” said Mary. “How shameful and sad to publicly lose and regain weight over and over. The thin cycles may be associated with fear and confusion, but the fat cycles carry the sadness of a life unfulfilled.
In the end, Mary concludes that this study contains a kernel of optimism: “Future weight loss is entirely possible and, at some point, the results might stick,” she said. “Weight loss, and all behavior change, follows the course of smoking cessation, where most people are not successful the first time they try, but they learn a little more with each attempt and they continue to get closer to their goal.”
August 21st, 2012