Perception of weight and psychological variables in a sample of Spanish adolescents

BACKGROUND: This study explored the relationship between body mass index (BMI) and weight perception, self-esteem, positive body image, food beliefs, and mental health status, along with any gender differences in weight perception, in a sample of adolescents in Spain. METHODS: The sample comprised 85 students (53 females and 32 males, mean age 17.4 ± 5.5 years) with no psychiatric history who were recruited from a high school in Écija, Seville. Weight and height were recorded for all participants, who were then classified according to whether they perceived themselves as slightly overweight, very overweight, very underweight, slightly underweight, or about the right weight, using the question “How do you think of yourself in terms of weight?”. Finally, a series of questionnaires were administered, including the Irrational Food Beliefs Scale, Body Appreciation Scale, Self Esteem Scale, and General Health Questionnaire. RESULTS: Overall, 23.5% of participants misperceived their weight. Taking into account only those with a normal BMI (percentile 5–85), there was a significant gender difference with respect to those who perceived themselves as overweight (slightly overweight and very overweight); 13.9% of females and 7.9% of males perceived themselves as overweight (χ(2) = 3.957, P < 0.05). There was a significant difference for age, with participants who perceived their weight adequately being of mean age 16.34 ± 3.17 years and those who misperceived their weight being of mean age 18.50 ± 4.02 years (F = 3.112, P < 0.05). CONCLUSION: Misperception of overweight seems to be more frequent in female adolescents, and mainly among older ones. Misperception of being overweight is associated with a less positive body image, and the perception of being very underweight is associated with higher scores for general psychopathology.