The impact of the size of the energy deficit on the rate of body weight in 6 months and willingness to continue reduction program conducted online-An intervention study.

Overweight and obesity are among the most serious public health problems, making new methods for their prevention, as well as treatment, constantly being sought. This study was designed as a 6 month intervention study. The main objective was to evaluate the effect of an energy deficit (10%, 20%, and 25%-groups D10, D20, and D25, respectively) on the rate of weight loss and waist and hip circumferences. The protocol was completed by 180 participants. Men as well as women comprised 90 patients each. The mean body mass index (BMI) was 30.5 ± 5.0 kg/m (min 21.3-max 49.2). Among the patients, there were 86 with a BMI indicating overweight. Fifty-four patients had class 1 obesity, while the remaining 30 patients had class 2 or greater obesity. After 6 months of intervention, the D10 group noted a 7.6% (median) reduction in weight, the D20 group a 9.9% (median) reduction in weight, and the D25 group a 10.3% (median) reduction in weight. After the intervention, 51.7% of patients chose to continue further weight reduction already outside the research protocol. Key factors influencing the willingness to stay on the diet longer than 6 months were higher baseline body weight and/or higher BMI and a rate of weight loss of at least 1.5% of body weight per month. In summary, it appears that a larger energy deficit (on the order of 20%-25%) is most appropriate in terms of weight loss lasting 6 months and motivation for continued therapy.