Fig. 1

Hypothetical associations between asthma, obesity and decreased physical activity. Pathway 1) Obesity is associated with asthma, and a so-called early-onset asthma-obesity phenotype has been detected [5]. Pathway 2) Asthma is hypothetically associated with decreased physical activity (PA), as it is accompanied with exercise-related limitations. Pathway 3) Obesity is hypothetically associated with decreased PA, as decreased PA is a cause of the imbalance in energy expenditure in obesity. Pathway 4) Obesity and asthma are hypothetically both related to decreased PA levels, therefore it is plausible that an interactive effect of asthma and obesity on decreased PA levels exists