Dynamics of body composition parameters in children with obesity against the background of hypocaloric diet in inpatient settings

Objective. To study the dynamics of body composition parameters in obese children against the background of hypocaloric diet in inpatient settings. Patients and methods. This study enrolled 89 children aged 5 to 17 (13 [12; 15]) years, of whom 44% were boys. The inpatient treatment program for obesity included a low-fat and low-carbohydrate diet with an energy value of 1668 kcal/day and therapeutic exercise. To assess the effectiveness of treatment, the clinical and anthropometric examination and body composition evaluation by bioelectrical impedance analysis (BIA) using the InBody 770 stationary analyzer (Biospace Co. Ltd., Korea) were performed at the beginning and at the end of inpatient treatment. Body fat mass (FM), fat-free mass (FFM), the amount of total body water, extracellular and intracellular fluid, protein, minerals, and the phase angle were determined. Results. At the beginning of the study, all children were found to have excess FM, and 47 (58%) had an increase in FFM due to muscle mass and intracellular fluid. By the end of treatment, there was a decrease in body weight, body mass index (BMI), BMI SDS, waist and hip circumference (p < 0.001) in all children. The amount of body fat decreased by 4.15% [2,6; 6,7]. Most children showed a statistically significant decrease in all FFM components by 2.4-2.7%. Protein loss during hospitalization was 0.3 kg [0.1; 0.4], mineral loss was 0.07 kg [0.01; 0.14]. The phase angle value at the beginning of the study was 5.5 [5.1; 6.1], at the end of the study – 5.4 [5.1; 5.9], p = 0.07. Conclusion. As a result of short-term adherence to the hypocaloric diet in inpatient settings, all children with obesity demonstrated a decrease in both FM and FFM against the background of a statistically significant decrease in BMI SDS. A comprehensive approach to treatment, combining the recommended calorie intake with the amount of protein according to the age group and structured physical activity, is necessary to preserve FFM in order to maintain resting energy expenditure. Body composition monitoring is required during the treatment of obesity. Key words: obesity, children, treatment, hypocaloric diet, fat-free mass, fat mass, body composition