Exercise and dietary changes may have health benefits that persist even after weight loss is reversed
shutterstock / Mr. Somkiat Vardan
People who have obesity and lose weight through diet and exercise programs still see long-term improvements in risk factors for heart disease and type 2 diabetes. This suggests that there are health benefits to losing weight even if you gain it back.
Weight loss reduces the risk of obesity-related chronic diseases. However, previous research has shown that only about half of obese people who participate in weight loss programs regain the lost weight within five years.
To understand its long-term health effects, Jamie Hartman-Boyce The University of Oxford and colleagues collected data on more than 60,000 adults from 124 randomized controlled trials of behavioral weight management programs. These programs encourage changes in diet or exercise habits to effect weight loss.
All trials included data on one or more cardiometabolic measures — such as the incidence of blood pressure, heart disease or cholesterol levels — for at least 11 months after the end of the program. In all trials, people participating in behavioral weight management programs lost an average of 2.8 kg more weight than people in control groups. They gained 0.12 to 0.32 kg more each year after the program ended.
People who participated in behavioral weight management programs also showed small but significant long-term reductions in cholesterol, blood sugar levels, and blood pressure. Five years after they finished a program, participants’ cholesterol ratio — which compares total cholesterol with the amount of high-density lipoprotein (HDL) or “good” cholesterol — was an average of 1.5 points lower than before the program. They also observed statistically significant reductions in systolic blood pressure and blood glucose levels. However, there was evidence that the more weight regained over time, the smaller and shorter-lasting these improvements were.
“When we really think about the impact of this on a population level, it suggests that fewer people may end up in hospital with different types of [cardiometabolic] disease,” says Hartman-Boyce. However, the team found no significant difference in the incidence of heart disease or type 2 diabetes between those who participated in the weight-loss programs and those who did not over five years. This may be because That’s because fewer studies collect data on these outcomes, Hartman-Boyce says.
Still, the fact that even modest changes in risk factors are meaningful, says Lauren Block At Northwell Health in New York. “A little bit can make a big difference” in terms of whether a person may need to take one or more medications, she says.
More research is needed to understand why weight gain doesn’t completely reverse the health benefits of weight loss. It may be that improvements in diet and exercise benefit health independent of weight loss, Block says. It may also be that the weight loss delays the onset of health problems, Hartman-Boyce says.
“If you’re losing weight, first of all, you’re not alone. But it also doesn’t mean it wasn’t worth it. It doesn’t mean there weren’t benefits,” she says.
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