Long-Term Weight Regain Outcome Post-Bariatric Surgery: Key Influencing Factors

Weight regain is a major long-term challenge in post-bariatric surgery. This study aimed to assess long-term weight regain (> 2 years) using a 25% cutoff from the maximal weight lost and identify associated factors.

The study involved men and women aged 18 to 65 who had bariatric surgery, assessing demographic, surgical, lifestyle, support, emotional health, and weight-related factors. The proportion of participants with optimal (less than 25% weight regain from the maximal weight lost) vs. non-optimal weight regain status (≥ 25% weight regain from the maximal weight lost) were calculated. Independent t-tests and chi-square tests compared participants by weight regain outcomes, followed by multivariable logistic regression using the ENTER method. An exploratory stepwise logistic regression model was also conducted.

The study included 234 participants (mean age of 46.00 ± 12.3 years). At follow-up, 20.3% had a healthy body mass index. Most participants (75.6%) presented optimal weight regain status. In the primary multivariable logistic regression model, male sex (odds ratio = 3.45), lower inappropriate eating behaviors (odds ratio = 3.17), smoking (odds ratio = 9.75), and dietitian support (odds ratio = 0.34) were significantly associated with optimal weight regain outcome. The smoking finding had a wide confidence interval and should therefore be interpreted as hypothesis-generating only. An exploratory stepwise model showed a similar pattern of findings and explained 27.3% of the variance in weight regain. The largest improvement in model fit occurred with the addition of eating behaviors (healthy, inappropriate, and bariatric), increasing explained variance by 13.5%.

Most individuals maintained favorable long-term weight outcomes two years post-bariatric surgery, but about one in four had significant weight regain. The strongest factor associated with long-term optimal weight maintenance response was eating behaviors. This underscores the key role of diet and ongoing support in sustaining bariatric surgery benefits.