[Weight misperception and physical fitness perception in relation to the physical activity level, dietary behaviour and psychosocial well-being].

Introduction: Most of the studies on weight misperception have been carried out in the US where it has been estimated that 20-40% of overweight or obese people underestimate their weight status. The perception of the physical fitness is a little studied variable but suggested as relevant in the adoption of healthy behaviours.

Objectives: The aims were to analyze weight misperception and physical fitness perception in adolescents, evaluating the relationship between weight misperception and physical fitness perception and body weight management behaviours (diet and exercise) as well as to analyze the relationship between weight misperception and psychosocial well-being.

Methods: A total of 655 students participated voluntarily in the study during which they completed a series of questionnaires. Weight and height of all participants were collected.

Results: Many young people misperceived their weight and its physical fitness. The majority of participants who were overweight or obese did not go on diet to manage their body weight. Those who overestimated their weight had the worst psycho-emotional state.

Discussion: The work is novel in Spain, it follows the methodology carried out in international studies on the same topic and the results are similar to those obtained in other populations.

Conclusion: Weight misperception and physical fitness perception influence the adoption of healthy body weight management behaviors and is related to psychosocial well- being of young people.