Effect of class attendance on an incentivized at-work weight loss program

Background/Objective: Multiple factors influence weight loss, including gender, age, and start weight. Our purpose was to determine the effect of class attendance in an incentivized employee weight loss program. Methods: 427 NASA Johnson Space Center employees (23% men, mean age 45.9 ± 10.8 yrs) paid a fee to enroll in a 12-week worksite weight loss program (Just Lose It). Program components included weekly measurements of body weight and lectures on fitness and nutrition, and prescribed exercise and diets administered by an exercise physiologist and a Registered Dietitian, respectively. At program completion, participants were awarded a partial refund of the enrollment fee for meeting attendance requirements of at least 10 of 12 classes and a full refund for meeting their predetermined weight-loss goal. Results: Mean weight loss and percent change at the 12th week were 2.92 kg (± 2.79 kg) and 3.23% (± 2.97%). Multiple regression analysis showed that gender, start weight, and class attendance contributed significantly (p<0.001) to weight loss variance. We converted class attendance to a categorical variable: low (<6, n=77), moderate (6-9, n=110), high (>9, n=237). Post hoc analysis showed that after adjusting for the effects of gender and start weight, each group lost significant (p<0.001) weight (low: 0.80 kg, moderate: 2.63 kg, high: 4.26 kg) and the group differences were also significant (p<0.001). Conclusion: Results showed that weight loss was influenced by class attendance level. This weight management program, utilizing both educational reinforcement and incentives, was effective in enhancing short-term weight loss.