Risk factors for weight gain: a longitudinal study in non-weight loss treatment-seeking overweight adults.

Purpose: To study some psycho-social variables in a sample of non-weight loss treatment-seeking overweight adults and to evaluate the weight outcome and the possible risk factors for weight gain over a 1-year period.
Methods: 167 Overweight (BMI range 25-29.9) subjects (66 % females, age 50 ± 10 years, BMI 28 ± 1.49) were recruited randomly in the surgeries of primary care physicians (PCPs). Data were collected through an ad hoc questionnaire with personal details and medical history. The following tests were administered: Binge Eating Scale (BES), Beck's Depression Inventory (BDI) and Body Uneasiness Test (BUT). Weight and height were measured using a mechanical balance with a stadiometer in standard conditions. At follow-up, 1 year after, updated data were collected for 125 subjects (75 %).
Results: At follow-up, there was remarkable weight instability: only 16 % of the subjects maintained their baseline weight, 40.8 % showed a decrease, and 43.2 % gained weight. In 14.4 % of cases, weight gain led to obesity (BMI ≥30). 18 individuals (14.4 %) reported having followed weight loss treatments in the last year, 11 among people with stable/decreased weight and 7 among those with weight gain. Lifetime comorbidity for anxiety and intense body uneasiness at baseline were the most important factors significantly associated with weight gain. Living with someone and habitually practicing sport resulted to play a protective role against weight increase.
Conclusions: Our study highlights the importance of a multidimensional assessment (medical and psycho-social) of overweight patients, aimed to identify individuals at greater risk of weight gain. They should receive targeted interventions.