Weight gain after 20 years of age is associated with unfavorable lifestyle and increased prevalence of metabolic disorders

Purpose: It is unclear what kind of modifiable lifestyle factors are associated with long-time weight gain in adulthood. To clarify the lifestyle behavior related to body weight gain since the age of 20 years, we explored the lifestyle risk factor, independently associated with excessive weight gain after 20 years of age as compared to those in subjects with a stable weight, with matching of age, gender, and the current body mass index (BMI). Patients and Methods: From baseline data of a general population-based cohort study, we designed a cross-sectional analysis collecting individual data of medical health check-ups and a questionnaire related to lifestyle, including amount of sleep, frequency of eating breakfast, average times per day engaged in walking and sitting in the prior year, and smoking habits. These data were compared between the subjects with weight gain ≥10kg (n=3601) and <10kg (n=3601) after age 20, matched by a propensity score model which included current BMI, age and gender. We used multivariable logistic regressions to assess the lifestyle factor’s association with high weight gain. Results: Participants who gained ≥10 kg were significantly more likely to sleep <5 hours or ≥9 hours per night, skip breakfast, engage in walking <1 hour per day, and sit ≥5 hours per day than those who gained <10kg. Multivariable logistic regressions analyses showed that, with adjusting for potential confounder, the lifestyles with the positive association with high weight gain were skipping breakfast (OR 1.252; 95% CI 1.053–1.489, vs regularly), long sleeping duration (9 hours/day≤ OR 1.613; 95% CI 1.018–2.557 vs 5≤-<7 hours/day), and former smoker (OR 1.163; 95% CI 1.008–1.343 vs never smoker), while walking duration was negatively associated with high weight gain. Furthermore, despite similar current BMI, participants with weight gain ≥10kg had significantly higher values for waist circumference, blood pressure, HbA1c, LDL-C, trigly-cerides, and hepatic enzyme levels than those with weight gain <10kg. Similarly, the prevalence rates of hypertension, dyslipidemia, metabolic syndrome (MetS), and former smoker were higher in the participants with weight gain ≥10kg. Conclusion: Major weight gain after 20 years of age was associated with unfavorable lifestyle factors and greater waist circumference, possibly leading to elevated risk for MetS and other non-communicable diseases. These findings highlight the importance of maintaining both weight at age 20 and a favorable lifestyle throughout adulthood.