Prior Weight Loss Attempts as Predictors of Weight Loss Success and Fitness in Overweight Adults

Abstract

There is limited data available regarding the effect of prior weight loss attempts on both weight loss and cardiorespiratory fitness. PURPOSE: To determine the effects of previous weight loss attempts and magnitude of weight change across these prior weight loss attempts on change in body weight and cardiorespiratory fitness in overweight adults participating in a 6-month behavioral weight loss program. METHODS: 222 overweight men and women (BMI = 33.0 ± 3.4 kg/m2; age 42.8 ± 8.6 yrs) participated in a 6-month behavioral weight loss intervention that focused on reducing energy intake to 1200–1500 kcal/d and progressively increasing exercise from 20 to 40 minutes per day on 5 days per week (100 to 200 min/wk). Body weight and cardiorespiratory fitness were assessed at baseline and 24 weeks, with cardiorespiratory fitness assessed using a progressive treadmill protocol. Prior to the intervention participants completed a questionnaire to assess their intentional weight attempts at weight loss that resulted in at least a 10 pound (4.5 kg) weight loss and the amount of weight lost during each weight loss attempt. RESULTS: There was a significant correlation between baseline body mass index (BMI) and both the number of weight loss attempts that resulted in at least a 10 pound weight loss (r = 0.13, p < 0.05) and total weight loss across these weight loss attempts (r = 0.15, p < 0.05). Subjects were grouped into tertiles based on the number of cycles of weight loss greater than or equal to 10 pounds (0 to 1.5 attempts, 1.6 to 4.5 attempts, ≥4.6 attempts). Weight loss resulted in a reduction in BMI of 2.8±1.9 kg/m2, 3.5±1.8 kg/m2, and 3.8±2.5 kg/m2 for weight loss attempts of 0 to 1.5 attempts, 1.6 to 4.5 attempts, and ≥4.6 attempts, respectively, with the change in BMI being significantly less in subjects with 0 to 1.5 attempts compared to subjects with either 1.6 to 4.5 attempts or ≥4.6 attempts (p < 0.05). Percent weight loss was 8.9±5.9%, 10.7±5.3%, and 11.5±7.4% for weight loss attempts of 0 to 1.5 attempts, 1.6 to 4.5 attempts, and ≥4.6 attempts, respectively (p=0.09). Fitness improved by 4.0±3.4min, with no significant difference between subjects with different prior weight loss attempts. CONCLUSION: Prior weight loss attempts may influence weight loss in a behavioral weight management program; however, this does not to impact changes in fitness. These results may indicate that numerous attempts at weight loss may need to occur prior to achieving significant weight loss. The long-term impact of these findings needs further evaluation. Supported by NIH grant HL067826