Association of Normal Weight Obesity on Physical Function in Young Women

Abstract

【Introduction】Normal weight obesity (NWO) occurs when a person exhibits a body mass index (BMI) in the normal range (18.5‐25.0 kg/m2) and a high‐fat percentage (≥30%). NWO is particularly common in young women, but its impact on physical functions in young women is unknow.

【Methods】A series of individual characteristics based on living condition surveys, namely, physical activity (International Physical Activity Questionnaire: IPAQ), nutrient intake (Brief Dietary History Questionnaire: BDHQ), body composition, and physical function, were determined in 33 young women (median age 20 years). Physical function parameters included chair stand test (i.e., peak reaction force per body weight; F/W, maximal rate of force development per body weight, (RFD/W), stable time) and 30‐second air stand test (CS‐30). The NWO criteria were a BMI in the normal range (18.5‐25.0 kg/m2) and a body fat percentage ≥30%.

【Results】Overall, 11 of 33 women (33%) were determined with NWO. We observed that BMI (p<0.001), total body muscle mass (p=0.04), and trunk muscle mass (p=0.001) were significantly higher in the NWO group than in the non‐NWO group. Moreover, we did not detect significant differences in lifestyle, nutrient intake, physical activity, chair stand test (F/W: p=0.438, RFD: p=0.363, stable time: p=0.877), and 30‐second air stand test (p=0.173) between NWO and non‐NWO groups.

【Conclusion】The comparison between NWO and non‐NWO groups showed no significant differences in lifestyle and physical function items. We concluded that the effects of lifestyle and physical function parameters on NWO is unclear and require further investigation.