Increased frequency of intentional weight loss associated with reduced mortality: a prospective cohort analysis

Abstract

Background: Due to the high prevalence of obesity and the difficulty in maintaining weight loss, repeated bouts of weight loss are a common occurrence. However, there are inconsistencies in epidemiological studies regarding repetitive weight fluctuations being associated with increased risk of mortality. Therefore, the purpose of this prospective cohort analysis was to determine the long-term association of the frequency of weight loss attempts on mortality.

Methods: This prospective cohort study used data collected from adult AARP members living in 6 states (California, Florida, Louisiana, New Jersey, North Carolina, or Pennsylvania) or 2 metropolitan areas (Atlanta, Georgia, or Detroit, Michigan) and participating in the National Institutes of Health-AARP Diet and Health Study between 2004 and 2006. Self-reported data were analyzed for 161,738 middle-aged adults. During an average 7 years of follow-up, 21,194 deaths were recorded. Hazard ratios of all-cause, cardiovascular, and cancer mortality were estimated adjusting for demographic, lifestyle, and behavioral risk factors.

Results: Increased frequency of weight loss attempts of at least five pounds was associated with lower mortality (p_trend < 0.010). Multivariate hazard ratios (95% confidence intervals) for all-cause death among individuals who successfully attempted weight loss compared with those who did not make any attempts were 0.94 (0.90-0.98) for 1-2 attempts, 0.96 (0.91-1.01) for 3-4 attempts, 0.91 (0.85-0.96) for 5-6 attempts, 0.91 (0.85-0.98) for 7-8 attempts, 0.87 (0.80-0.95) for 9-10 attempts, and 0.88 (0.82-0.94) for 11+ attempts. Similar results were noted for men and women, participants with healthy weight and overweight/obesity, and even among those who gained weight over time. Protective associations were also observed for deaths due to cardiovascular disease and cancer.

Conclusions: Increased frequency of intentionally losing at least five pounds in mid-life was associated with a lower risk of future death. Repeated attempts with moderate amounts of weight loss may provide benefit in terms of longevity.

Trial registration number: ClinicalTrials.gov number, NCT00340015.

Keywords: Mortality; Obesity; Prospective cohort; Weight loss.

Fig. 1

Risk of all-cause mortality associated with frequency of weight loss attempts of at least 5 lbs in the previous 20 years. Multivariate hazard ratios (HRs) are adjusted for age, sex, race/ethnicity, education level, health eating index total score, physical activity, sedentary time, smoking, chronic diseases, self-report overall health, marital status, age at retirement, age at menopause, and starting BMI. Multivariate HRs shown in black are additionally adjusted for weight change (WC) over time

Fig. 2

Stratified analysis of proportional hazard ratios for all-cause mortality associated with frequency of weight loss (WL) attempts of at least 5 lbs over the previous 20 years, by (A) historical BMI and (B) life course weight loss. Hazard ratios and 95% confidence intervals (CI) are adjusted for age, sex, race/ethnicity, education level, healthy eating index total score, physical activity, sedentary time, smoking, chronic diseases, self-reported overall health, marital status, age at retirement, age at menopause, starting BMI, and weight change. Weight losers: reference group = 1–2 attempts

Fig. 3

Proportional hazard ratios for all-cause mortality based on the joint effects of the frequency of weight loss attempts and the total weight loss based on the sum of those attempts the previous 20 years (n = 161,738). Hazard ratios and 95% confidence intervals (CI) adjusted for age, sex, race/ethnicity, education level, healthy eating index total score, physical activity, sedentary time, smoking, chronic diseases, self-report overall health, marital status, age at retirement, age at menopause, starting BMI, and weight change

Fig. 4

Cardiovascular (A) and cancer (B) specific mortality HRs for frequency of weight loss attempts in the previous 20 years. Multivariate sub-distribution hazard ratios and 95% confidence interval (CI) adjusted for age, sex, race/ethnicity, education level, healthy eating index total score, physical activity, sedentary time, smoking, chronic diseases, self-report overall health, marital status, age at retirement, age at menopause, starting BMI, and weight change (WC)