Maternal alcohol and tobacco consumption and the association with their 9 to 14-year-old children's Body Mass Index

Aims: Little is known about impact of maternal alcohol and tobacco consumption on adolescents' body size. The purpose of this study was to evaluate whether maternal alcohol or tobacco consumption is associated with their children's body size in adolescence, assessed by Body Mass Index (BMI).

Methods: This study was conduct in subjects recruited into the Finnish Health in Teens cohort (Fin-HIT) between 2011 and 2014. A total of 4525 subjects aged between 9 and 14 years and their mothers or female adults responsible for the children were analysed. Relative risks (RR) and 95% confidence intervals (CI) were estimated using Multinomial Logistic Regression.

Results: Most children were normal weight (74.5%), 10.6% were underweight and 14.9% were overweight or obese. Among mothers, 50.6% were never smokers, 35.7% were former smokers, and 13.7% were current smokers. Alcohol consumption was classified by Alcohol Use Disorders Identification Test (AUDIT), 12.7% were abstainers (score=0), 65.0% were low-moderate drinkers (scores 1-4) and 22.3% were harmful drinkers (scores ⩾5). There were statistically significant associations between currently smoking mothers and children's overweight (RR=1.36; 95% CI: 1.05-1.76). There was an inverse association between maternal former smoking and children's underweight (RR=0.70; CI: 0.56-0.87) compared with never smoker mothers. Among children in puberty, abstainer mothers were more likely to have underweight children compared with low-moderate mothers (RR=1.57; 95% CI: 1.03-2.41).

Conclusions: Current smoker mothers were associated with children's overweight and former-smoker mothers were inversely associated with the children's underweight. Being an abstainer mother was associated with the children's underweight in puberty stage. If other studies confirm these results, public health interventions aiming at healthy weight of adolescents should target the whole family, not only the adolescents themselves.