Brief group cognitive behavioral treatment in addition to prescriptive diet versus standard care in obese and overweight patients. A randomized controlled trial.

Abstract

The beneficial effect of cognitive therapy was found particularly in eating disorders, but, to date, it has rarely been studied in obese patients without eating disorders. The aim of this pragmatic randomized clinical trial was to evaluate the effectiveness of a novel brief group cognitive behavioral treatment (CBT), accepted and performed in clinical practice, in addition to a prescriptive diet with respect to the prescriptive diet alone (standard care), in obese and overweight outpatients without eating disorders. One hundred sixty three patients [44 men and 119 women; 45 ± 11 yr; mean body mass index (BMI) of 32 ± 4 kg/m2] aged 18–65 years who were from overweight (BMI between 25 and 29.9) to 2° class obese (BMI between 35 and 39.9 kg/m2) were followed for 12 months in a public obesity ambulatory. The study was based on a nutritional intervention lasting for six months. Weight loss was obtained with a hypo caloric balanced diet. Standard care consisted in a low-calorie diet, and a control visit every three months. Group CBT patients received the same diet but in addition they attended a series of seven subsequent meetings divided in small groups. Primary outcome is defined as the percentage of patients in each group achieving a 10% reduction of body weight at 12 months in comparison with baseline value. After randomization, at baseline patients underwent laboratory tests, bioelectrical impedance analysis, ECG and psychometric tests, and they were followed-up at six and 12 months. The average weight loss obtained at six and 12 months was respectively 6.0% and 7.44% for all patients, and this is in accordance with other similar studies. The primary outcome has been reached by 19 patients (24%) out of 78 who concluded the follow-up. Considering an ITT univariate analysis, the primary outcome was independent from treatment arm (OR .854, CI .39–1.871, p = 0.633) and the two treatments were substantially similar. Metabolic parameters (glucose levels, lipid profile, blood pressure), as expected, ameliorated in both groups during follow-up. The only independent predictor of successful weight loss was baseline glucose levels (OR 1.05, CI 1.009–1.09, p = 0.04), thus representing a higher risk of disease perceived by patients. A brief group CBT, when added to standard care, was not superior to standard care alone in obese patients. The peculiar course of CBT planned only in the first six months, as well as the absence of a pure cognitive analysis may have impacted on the CBT success lower than expected. Further studies are needed in order to determine if longer intervention may be effective and feasible in a real-life primary care setting. Clinical trial.gov (n° NCT01686854).