Background
This study investigated the relationships between global perfectionism (its functional and dysfunctional aspects) and three types of health behaviors: fruit and vegetable intake (FVI), consumption of sweet and salty snacks, and physical activity. It was hypothesized that indices of functional perfectionism would predict engaging in healthy behavior, with gender moderating these associations.

Participants and procedures
Data were collected among 845 adolescents (59.20% girls) aged 13 to 20 years old (M = 16.52, SD = 0.92). At the baseline, participants filled out the Frost Multidimensional Perfectionism Scale and measures of nutrition behavior and physical activity. The measurement of nutrition behavior and physical activity was repeated at 12-month follow-up.

Results
The moderator analysis indicated that FVI as well as consumption of sweet and salty snacks measured at 12-month follow-up were explained by functional global perfectionism (Organization and Personal Standards dimensions), but this effect was stronger among girls. Physical activity measured at 12-month follow-up was explained by functional perfectionism (Organization and Personal Standards dimensions), but this effect was stronger among boys. The effects were found after controlling for respective behaviors assessed at the baseline. Dysfunctional dimensions of global perfectionism (Concern over Mistakes, Parental Expectations, Parental Criticism, Doubts about Actions) were unrelated to indices of behavior at follow-up.

Conclusions
Functional global perfectionism may represent an individual resource variable, facilitating uptake and maintenance of healthy diet and physical activity, and therefore foster prevention of obesity among adolescents.