title: Relationships between physical activity, obesity and meal frequency in adolescents.
abstract: OBJECTIVE
  The purpose of this study was to assess the associations and impact of increased meal frequency, physical activity and 'skipping' breakfast on obesity levels in a sample of urban adolescents, aged 13-17 years old, from Porto, Portugal.
  
  
  METHODS
  Overweight and obesity were defined according to age- and sex-specific BMI cut-points. Daily meal frequency was assessed by questionnaire. Self-reported physical activity was recalled.
  
  
  RESULTS
  The proportion of overweight/obese girls (p < or = 0.05) and boys (p < or = 0.001) that consumed fewer than three meals was significantly higher than those reported from normal-weight counterparts. While no statistically significant differences were reported in girls, obese boys skipped breakfast significantly more (13% vs 5.6%; p < or = 0.05) than normal-weight counterparts did. Normal-weight boys but not girls were significantly more active (p < or = 0.01) than obese peers. An additional meal in boys (OR: 2.75; p < or = 0.05) and girls (OR: 1.97; p < or = 0.05) reduced the risk of being overweight/obese. Regardless of gender, breakfast skipping is not seen as a predictor of being overweight/obese. However, boys (OR: 2.10; p < 0.003), but not girls, who were moderately active were more likely to be of normal weight.
  
  
  CONCLUSIONS
  The data indicate that increased meal frequency may have a beneficial effect on a reduced BMI. Physical activity and breakfast skipping may be candidate targets for prevention programmes aimed at reducing overweight/obesity among adolescents.
authors.affiliation: Research Centre in Physical Activity, Health and Leisure, Faculty of Sports, Porto University, Portugal. jmota@fade.up.pt
authors.forename: Jorge
authors.initials: J
authors.lastname: Mota
authors.forename: Filipe
authors.initials: F
authors.lastname: Fidalgo
authors.forename: Ricardo
authors.initials: R
authors.lastname: Silva
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Ribeiro
authors.forename: Rute
authors.initials: R
authors.lastname: Santos
authors.forename: Joana
authors.initials: J
authors.lastname: Carvalho
authors.forename: Maria Paula
authors.initials: MP
authors.lastname: Santos
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000886:Anthropometry; D015992:Body Mass Index; D016021:Epidemiologic Studies; D005247:Feeding Behavior; D005260:Female; D015438:Health Behavior; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D008297:Male; D009043:Motor Activity; D009752:Nutritional Status; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D050177:Overweight / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D011174:Portugal / Q000453:epidemiology; D011795:Surveys and Questionnaires