Variables predictive of adherence to diet and physical activity recommendations in the treatment of obesity and overweight, in a group of Spanish subjects

OBJECTIVE: To assess the factors that could predict a successful completion of a weight loss program. STUDY DESIGN: A single-centered, cross-sectional, prospective study conducted over 4 y. SUBJECTS: Data were obtained on 1018 overweight subjects (788 women, 230 men) aged 14.8-76.3 y (mean 38.4) and body mass index (BMI) of 31.7 (range 25.03-57.1) seeking help to lose weight at a specialist obesity clinic. MATERIALS AND METHODS: A program involving a hypocaloric, Mediterranean diet was prescribed plus recommendations for free-time exercise and day-to-day activity. Follow-up was weekly until the desired weight loss was achieved ('successful completion') or the patient dropped-out of the program ('failure'). Cox's regression analysis was used to evaluate success and the variables included were compliance with the program, age, gender, initial BMI, physical activity, alcohol consumption, smoking habit, hypertension, diabetes, hypercholesterolemia, cardiovascular disease, previous dietary programs, cause of obesity, age at which excessive weight was first noted and parental obesity. RESULTS: Factors predictive of completion were: gender (males responded better), previous dietary programs (predictive of dropout), initial BMI (higher index, lower completion), and age (younger age, poorer outcome). There was an interaction between parental obesity and offspring childhood obesity. Absence of parental obesity and adult-onset obesity had a higher probability of program completion. CONCLUSIONS: In a standard weight reduction program the recommendations of dietary restriction and moderate exercise seems less effective for women, persons with high BMI, younger age groups and those who have had other attempts at weight loss. Poorest outcomes applied to those subjects with childhood obesity and who had obese parents.