The correlation of diet anti-oxidant index with appetite, serum levels of BDNF, NPY and total serum anti-oxidant capacity in obese women

Abstract

Objective: Obesity is a complex metabolic disease caused by excessive fat accumulation. According to the latest World Health Organization report in 2014 it has affected more than 600 million people worldwide. Considering the role of neuropeptide Y (NPY), brain-derived growth factor (BDNF) and oxidative stress in obesity, the aim of this study was to determine the relationship between dietary total antioxidant capacity (TAC) and appetite, serum TAC, BDNF and NPY levels in obese women. Subjects and Methods: Forty-five obese women and 45 normal-weight women in the age range of 20-50 years were included in the study by convenience sampling. Subjects were determined based on body mass index (BMI). Demographic characteristics such as age, education, history of chronic disease, dietary supplements, marital status, etc. were collected using a demographic questionnaire. Appetite status, stress, physical activity and food intake were assessed as possible confounders using related questionnaires. Physical activity was assessed using the International Questionnaire Physical activity questionnaire and appetite were assessed using a visual analog scale questionnaire. Biochemical parameters of NPY, BDNF and serum TAC levels were evaluated using ELISA technique from serum samples of patients. Food TAC was calculated using a 147-item feed frequency questionnaire. Results: The results of the present study showed that dietary intake and serum TAC levels were significantly higher in obese individuals than in normal weight individuals (P <0.05); Although this significance for dietary TAC disappeared after adjusting for the effect of energy intake and age, it remained significant for serum TAC levels even after adjusting for energy intake and age. On the other hand, in obese subjects, dietary TAC had a significant positive relationship with serum TAC (P <0.05) but in normal weight individuals, no such significance was observed; Also in normal weight individuals, dietary TAC had a significant positive relationship with serum BDNF levels. Appetite status was not significantly associated with any of the variables of serum and dietary TAC, serum BDNF and NPY levels. Conclusion: High dietary TAC in obese subjects compared to normal weight people was due to higher energy intake; thus, after adjusting the effect of energy intake values, no significant difference was observed. On the other hand, observing significant correlations between dietary TAC with serum TAC and BDNF levels can be a prelude to the development of dietary programs based on antioxidant capacity of diet to reduce the obesity compications.