[Nutrition and body composition in young women with various leptin and ghrelin levels]

Abstract

Body mass and its composition depend on the energy equilibrium due to the consumption of energy-intensive macronutrients and energy expenditure under strict neuroendocrine control. Leptin and ghrelin are the most important regulators of the energy balance; they modulate the redistribution of substrate flows in metabolic pathways. The aim of the research was the assessment of nutrient intake in conjunction with the analysis of body composition and primarily hormonal regulators of energy balance in young women with various body mass index (BMI) values. Material and methods. 88 girls aged 18-22 were examined. Based on the definition of BMI, three groups were formed: group 1 - young women with BMI <18.5 kg/m², underweight (UW); group 2 - BMI of 18.5 to <24.9 kg/m², normal weight (NW); and group 3 - BMI of >24.9 kg/m², overweight (OW). Body composition was determined using bioelectrical impedance analysis. Nutrition was assessed using the 24-hour food recall. Enzyme-linked immunosorbent assay was used to measure leptin and ghrelin concentrations. Results. The study of nutrition in young women with various energy balances revealed intergroup differences in macronutrient and calorie intake. Underweight students demonstrated insufficient consumption of energy (1267±114 kcal/day) from all macronutrients. Overweight and obese young women ate a lot and consumed higher than daily average amounts of proteins (95.7±8.5 g) and fats (129.5±12.2 g). Young women with normal body weight consumed excess energy from fats - 33.7±1.1% (the same as in overweight subjects - 39.3±2.4%), but the relative carbohydrate and protein intake was below recommended level. An excess of energy consumed with food reflected in the degree of adipose tissue development and the energy balance of the examined persons. Leptin concentration increased at higher BMI values and depended on adipose tissue level, amounting to 5.0 [4.2; 5.7], 14.2 [9.7; 14.7] and 20.3 [14.8; 21.3] pg/ml (p<0.009). Ghrelin level was 13.0-14.2% higher in overweight subjects (2.09 [2.00; 2.27] ng/ml) vs. other groups (p<0.003). Conclusion. Students with various BMI values demonstrated various dependences between macronutrient consumption and body composition. The results show that fat intake play a more important role in adipose tissue formation in young women than diet carbohydrates. Overweight and obese subjects have additional regulation factors associated with a stressed regulatory system.

Keywords: body composition; body mass index; dietary intake; ghrelin; leptin.