Changes in dietary habits and eating practices in adolescents living in urban South Africa: the birth to twenty cohort.

OBJECTIVE To assess changes in the dietary habits and eating practices of a longitudinal cohort of adolescents over a 5-y period living in Soweto and Johannesburg. METHODS An interviewer-assisted questionnaire was used to gather data on the dietary habits and eating practices across three environments: in the home, in the school, and in the community. Participants (n = 1451, 49.1% male, 89% black, and 11% with mixed ancestry) 13, 15, and 17 y old with complete data were included in the analyses. RESULTS The weekday breakfast consumption decreased over the 5-y period, from 76% to 65% (P < 0.001); participants consumed breakfast during the weekend more regularly but this also decreased with age. Snacking while watching television increased with age, from 3.6 ± 4.6 to 6.7 ± 5.9 snacks/week, with female subjects consistently consuming more snacks than male subjects (P < 0.01). Two-thirds of participants ate their main meal with their families on most days at all three ages. Fast-food consumption increased by half a portion/week over the 5 y and confectionery consumption stayed the same, around 9 items/week in male subjects and 10 items/week in female subjects (P < 0.02). Lunch box usage decreased with age; conversely, the number of tuck shop purchases increased. CONCLUSION Poor eating habits in all three environments were found; the participants' propensity for foods that were energy dense and micronutrient poor was high. This study also found that dietary patterns are well established by 13 y of age.