A new study from the University of Gothenburg brings encouraging news for people who have undergone significant weight loss through bariatric (weight-loss) surgery. The research shows that even if some of the lost weight is regained later, there are still lasting health benefits—especially when it comes to overall life expectancy and cancer risk.
The study, published in The Lancet Regional Health – Europe, explored what happens when people who lose a lot of weight regain part of it. This is an area scientists haven’t studied much before, even though it affects many people who go through weight-loss surgery.
Researchers analyzed health data from 1,346 participants in the long-running Swedish Obese Subjects (SOS) study, the world’s largest and most detailed study of the long-term effects of bariatric surgery. These participants had surgery to treat obesity and were tracked for decades using national health records in Sweden.
On average, participants lost about 30 kilograms (66 pounds) one year after surgery. However, four years later, over half had regained at least 20% of the weight they had lost.
To better understand the health effects of this weight regain, researchers compared two groups:
- One group that regained a significant portion of the weight they initially lost.
- Another group that maintained most of their weight loss or regained only a little.
The main findings were hopeful:
- Life expectancy and cancer risk were not affected by partial weight regain. Both groups had the same rate of new cancer cases and similar survival rates over the years.
- This means that even if people regain some weight, they still enjoy the same long-term benefits when it comes to living longer and avoiding cancer as those who kept the weight off.
However, the study did find differences in other areas of health:
- Microvascular diseases (which affect small blood vessels and can lead to problems like kidney disease, eye damage, and nerve issues) were more common in the group that regained more weight. The rate was 11.0 cases per 1,000 person-years compared to 8.7 in the group that maintained their lower weight.
- There was also a slight increase in cardiovascular diseases such as heart attacks, strokes, and heart failure among those who regained weight. The rate was 15.7 cases per 1,000 person-years, compared to 13.0 in the group with better weight maintenance.
Dr. Kajsa Sjöholm, one of the lead researchers, emphasized the significance of these findings. “Until now, the effects of weight regain following major weight loss on long-term health and mortality have remained unknown.
What we’re now seeing is that even those who regain some of their weight loss experience long-lasting positive effects with the same life expectancy as those who maintain their lower weight,” she said.
She added that while life expectancy is not reduced, weight regain still brings other challenges. These include higher risks for heart problems, small blood vessel disease, joint pain (especially in the hips and knees), and social stigma related to weight.
Review and Analysis
This study delivers an important message: losing weight—especially through surgery—can lead to long-lasting health improvements, even if some of the weight comes back. It’s a hopeful sign for people who feel discouraged by weight regain, which is common and difficult to avoid long-term.
One of the most reassuring findings is that cancer risk and life expectancy stayed the same whether or not people maintained their lowest weight. This suggests that the body may “remember” the period of lower weight in a positive way, keeping some of the benefits even after some regain.
At the same time, the study warns that regaining a lot of weight does increase the risk of heart and blood vessel problems, though the differences are not huge. This underlines the importance of long-term support after weight-loss surgery—not just for keeping weight off, but for managing heart health, mobility, and mental well-being.
In summary, while maintaining weight loss is ideal, partial weight regain is not a failure. People can still enjoy many of the health benefits of weight loss, especially if they continue to manage other risk factors like blood pressure, cholesterol, and blood sugar.
This research can offer reassurance and motivation to people on weight-loss journeys, showing that progress—even if imperfect—still matters.
If you care about weight loss, please read studies about orange that could help obesity, and a berry that can prevent cancer, diabetes and obesity.
For more health information, please see recent studies about whole grains are key to managing waist size, blood pressure, and blood sugar.
The research findings can be found in The Lancet Regional Health – Europe.
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