The second baseline study was conducted in 1985 and included a representative sample of 2498 teenagers drawn from the Danish Civil Registration (CPR) and invited to participate in the study with the aim of validating the results from the first baseline sample. The study consisted of a questionnaire with virtually the same questions as the questionnaire from 1983. A short 28-item food frequency questionnaire (FFQ) was added to the questionnaire, as well as a few questions about dietary habits.