ABSTRACT

Objective: To estimate the effect of a low energy diet on body fat mass measured by bioelectrical impedance (BIA) in overweight (BMI > 25 < 30) and obese women (BMI > 30). Design: Randomised six weeks trial. Methods: The studied group consisted of 86 women aged 20-67 attended the Outpatients Clinic of Metabolic Disorders. Dietary assessments were performed by 24-hour dietary recall. Body fat mass was measured by bioelectrical impedance method and by skinfolds thickness method. Percent body fat and fat free mass was estimated from equations based on BMI and skinfolds thickness. Results: In overweight women after 6 weeks of dietary treatment mean intake of energy decreased from 10071 ± 2678 kJ to 4560,6±1405,8 kJ, total fat intake from 88,7±33,9 g/d (33,4% of energy) to 38,8 ±19,9 g/d (31,1% of energy), protein intake from 89,5 ±36,5 g/d (14,8% of energy) to 50,7 ±16,9 g/d (19,0% of energy), carbohydrates intake from 312,7 ±106,6 g/d (51,8% of energy) to 134,5 ±53,7 g/d (50% of energy). In obese women mean intake of energy decreased from 10376,3 ±2953,9 kJ to 4665,2 ± 1380,7 kJ. The value of total energy, total fat and saturated fatty acids intake correlated with body weight, BMI and body fat. After dietary treatment the body weight decreased by 2,4 kg (3,3%) in overweight women and by 3,9 kg (4,1%) in obese women and percent of body fat decreased by 1,6% and 2,3%, respectively. Body fat mass determined by BIA method significantly correlated with skinfolds method by Siri, Schutte, Rathbun, Brożek, Keys-Brożek, and BMI method by Webster, Deurenberg. Conclusion: BIA method may be a helpful tool for the analysis of changes in total body composition occurring under obesity treatment.