OBJECTIVES: To stress the importance of social and environment (nutritional) factors in determining the growth spurt during puberty and the risk of excessive adiposity, two contrasting adolescent populations, one from a rural area of Senegal (West Africa) and the other from Martinique (French West Indies), were compared. DESIGN: Cross-cultural comparison of contrasting populations. Adolescents from Senegal belonged to a cohort followed up since 1995. Adolescents from Martinique participated in a cross-sectional nutritional survey that covered the entire island. SUBJECTS: A total of 507 adolescents (mean age: 14.3+/-0.7 years) from Senegal (319 girls and 188 boys) and 703 adolescents from Martinique (351 boys and 352 girls) were surveyed. RESULTS: Differences in growth and maturation were striking: boys in Martinique were 22.7 kg heavier and 20.1 cm taller than boys in Senegal. Differences were less important for girls but still evident: 12.6 kg in weight and 10.5 cm in stature. In Senegal, there were virtually no overweight adolescents, but 18% of girls and 50% of boys could be considered as malnourished. In Martinique, 19% of girls and 23% of boys were overweight or obese. Adolescent girls from Martinique were also sexually more mature than adolescent girls from Senegal. When comparisons were repeated after Senegalese girls reached menarche, differences in weight and body mass index disappeared, but Senegalese girls were still shorter than girls from Martinique. CONCLUSIONS: Adolescents are extremely susceptible to nutritional changes and their particular situation needs to be incorporated into nutritional prevention programmes.