Weight cycling may not be as bad as we once thought.
Obesity is a huge problem around the globe. The fact is that obesity and obesity-related illnesses have substantially increased in prevalence in modern times and the cost could cripple the world economy. The associated chronic health conditions such as arthritis cardiovascular disease, cancer, type 2 diabetes, heart disease, and increased mortality rate should have the entire world concern. Although weight loss has long been associated with improved outcomes, medical experts have long pointed to weight cycling as a concern and confused dieters.
Despite the well-known health benefits of weight loss in obese people, researchers have reported that cycles of weight loss and regain, or weight cycling, are associated with increased mortality. The problem with most of the research is the data and methods contained some bias. Often studies compared groups that did not necessarily have the same risk when trying to support the belief that weight cycling is harmful. The question is not whether weight cycling is harmful. The question should be whether weight cycling with weight loss is harmful compared to obesity with no weight loss at all. The effect of weight loss on longevity is clear but weight cycling as harm is less clear.
There a relationship between intentional weight change and improved mortality (moderate and not excessive), but is this pattern is often repeated loss-regain cycle referred to as weight cycling or “yo-yo dieting” harmful? The good news is that researchers attempted to tackle this question in a mouse model. In the study. researchers looked at whether weight loss must be sustained to achieve health and longevity benefits through a randomized controlled feeding study of weight cycling in mice.
They used 900 obese mice to complete the study and randomized them into a test group in which they induced weight loss and regain or the control in which they fed a diet to maintain obesity. The study found that weight loss significantly reduced adipose mass and adipocyte size in both sexes and weight cycling caused the animals to regained body fat and cell size during refeeding. The good news is that weight loss resulted in a dose-dependent decrease in mortality despite weight regain when compared with the sustained weight group.
The bottom-line: The study shows that weight cycling significantly increased life-span relative to remaining with obesity and had a similar benefit to sustained modest weight loss. This is a mouse model, but keep trying to lose weight. Ultimately, it is better to keep trying so you ultimately be a success. This study, to me, indicates that there is some doubt about how harmful cycling is when compared to the overweight and obese that do not attempt weight loss. Human weight loss is much more complex than mice. It is much more variable and harder to control. We cannot cage humans and severely control their intake and exercise. More research is needed
- D. L. Smith Jr. et al., “Weight Cycling Increases Longevity Compared with Sustained Obesity in Mice,” Obesity, pp. 1733–1739, Oct. 2018 [Online]. Available: http://dx.doi.org/10.1002/oby.22290