Dietary and Biochemical Characteristics Associated with Normal-Weight Obesity

Background: Inflammation and oxidative stress have been reported to be higher in subjects with normal weight obesity (NWO) syndrome [normal body mass index (BMI) (<25 kg/m²) but excessive body fat (for women ≥ 30% and for men ≥ 20%) according to World Health Organization (WHO) definitions]; however, it is unclear whether this is due to inadequate dietary antioxidant intake or the pathophysiology of NWO. The aim of present study was to assess the association between dietary factors and body antioxidant status with NWO syndrome in male university students. Methods: This study was a case-control study carried out on ninety age-matched male university students [30 normal weights (NW), 30 NWO and 30 overweight-obese (OB)]. A validated food frequency questionnaire (98 items) and 3-day 24-h recalls were used for dietary assessment. Total antioxidant capacity (TAC) of diet and serum and high-sensitive C-reactive protein (hs-CRP) concentrations were also measured. Results: Dietary intake of fruits (frequency factor (FF) = 2.3 vs 2.9, p < 0.05), legumes (FF = 0.7 vs 1.3, p < 0.01), nuts and seeds (FF = 0.4 vs 0.8, p < 0.05), beta-cryptoxanthin (p < 0.05), lycopene (p < 0.05) and serum TAC levels (p < 0.01) were significantly lower in NWO compared to the NW group. No significant differences in these parameters were observed between NWO and OB group. A significant negative correlation was observed between serum TAC levels and BMI (r = -0.57, p < 0.001) and body fat percent (r = -0.52, p < 0.001). Conclusions: This study shows that NWO male subjects consume lower amounts of dietary antioxidants and share the same low body antioxidant status as obese individuals, although they appear lean.