Olfactory Capacity and Obesity in Chilean Adolescents

Childhood obesity is a global issue, influenced by energy-dense foods and powerful cues that affect brain areas regulating food intake. The olfactory system, linked to food preferences and consumption, is inversely related to body mass index. However, no studies have assessed the possible effect of eating behavior traits on the relationship between olfactory capacity and obesity.

The aim of this study was to examine whether olfactory capacity, eating behavior traits, and body mass index are associated with obesity in adolescents.

An analysis of 204 Chilean adolescents was undertaken in a cross-sectional study. The proportion of participants with normal weight was found to be 39.2%, that of overweight was 25.9%, and that of obesity was 34.8%. Anthropometric measurements (weight, height, BMI Z-score), eating behavior, and olfactory capacity were evaluated. The Child Eating Behavior Questionnaire (CEBQ) and Food Reinforcement Value Questionnaire (FRVQ) were used to assess eating behavior. The Sniffing sticks test was used to assess olfactory capacity.

In the global sample, 1.0% had anosmia, 20.5% had hyposmia, 61.0% had normosmia, and 17.5% were supersmellers. Girls showed higher odor identification percentages than boys (p = 0.01). No gender differences were found in olfactory threshold, discrimination, identification, or TDI (threshold-discrimination-identification) scores, nor nutritional status. Stratified analysis revealed that girls with obesity had significantly lower odor discrimination capacity compared to those with normal weight.

the study highlights a potential link between olfactory function and obesity, with obese girls showing reduced odor discrimination compared to normal-weight girls. Further research is needed to explore these mechanisms and their implications for targeted obesity interventions.