[Agreement between self-perception of body image and nutritional status in a Chilean population]

Introduction: obesity is a public health problem. No significant decrease in the prevalence of obesity has been globally observed. A better understanding of the factors that can influence obesity is necessary, one of them being self-perception of body weight. Objective: to determine the agreement between self-perception of body image and nutritional status in a Chilean population. Methods: an analytical cross-sectional study was carried out based on the Chilean National Health Survey 2016-2017. Nutritional status was measured by body mass index (BMI) and self-perceived body weight. Agreement was estimated by the kappa index and weighted kappa index. These indices were specified according to sociodemographic variable. Results: the total number of participants was 5483, with 51 % (95 % CI: 48.7-53.5) corresponding to women. Mean age was 43.2 years (95 % CI: 42.4-44.0). The kappa index showed a low concordance (kappa, 0.194; 95 % CI: 0.177 to 0.211) among women, people from rural areas, and subjects with fewer years of education. The global weighted kappa was 0.325; 95 % CI (0.168-0.482). Conclusions: underestimation of nutritional status can lead to negation of the problem generated by excess body weight. Recognizing nutritional status is a critical stage to initiate behavior changes and start having healthy eating habits. More than half of Chileans present distortion of body image, prevailing underestimation of body weight.