Aims: The study aimed to determine whether alcohol use during late adolescence contributes to the weight gain from adolescence to young adulthood or risk of obesity or waist circumference at young adulthood.
Methods: A population-based, longitudinal study of 5563 Finnish twins born in 1975–1979 and surveyed at ages 16 (T1), 17 (T2), 18 (T3) and 23–27 (T4) years. Drinking habits, height and weight were self-reported at T1, T2, T3 and T4; waist circumference was self-measured at T4. As potential confounders, we used smoking, diet, physical activity, place of residence, socio-economic status and parents' body mass index (BMI).
Results: Compared to the reference group (drinking once to twice per month), the BMI increase from T3 to T4 was less among abstaining men (−0.62 kg/m2, (95% CI −1.04, −0.20)) and among women in those drinking less than monthly (−0.38 kg/m2, (−0.71, −0.04)). In women, at least weekly drinking was associated with larger waist circumference (Beta 1.55 cm, (0.48, 2.61)), but this became statistically non-significant after adjusting for potential confounders. In a multilevel model for change, drinking frequency was not associated with weight change in women; in men, a negative association was seen, but it was statistically non-significant after adjusting for potential confounders.
Conclusions: These results from a population-based study with a large set of confounding variables suggest that alcohol use during adolescence has at most a minor effect on weight gain or development of abdominal obesity from adolescence to young adulthood.