Parental pre-pregnancy obesity and the risk of offspring weight and body mass index change from childhood to adulthood.

The purpose of this study was to examine the association of parental pre-pregnancy weight and body mass index (BMI) on offspring weight and BMI change from childhood to adulthood. We analysed BMI data from a subsample of parents (n = 1494) from the Mater-University of Queensland Study of Pregnancy cohort that started in the early 1980s in Brisbane, Australia: data were collected at pre-pregnancy and then also for offspring at 5, 14 and 21-year follow-ups. Multiple regression for continuous outcomes and multinomial regression for categorical outcomes were performed. A total of 14.7% of offspring experienced BMI change from normal at 5 years to overweight or obese (OW/OB) at 14 years, 15.3% of normal at 14 years to OW/OB at 21 years and 22.8% from normal at 5 years to OW/OB at 21 years. Overall, the strength of the association of parental BMI with offspring BMI was stronger as offspring become older. Pre-pregnancy parental BMI differentially impacts offspring OW/OB across the life course. For every unit increase in paternal and maternal BMI z-score, offspring BMI z-score increased, on average, by between 0.15% (kg m-2 ) and 0.24% (kg m-2 ) throughout all three stages of life when both parents were OW/OB; these associations were stronger than with one parent. Parental pre-pregnancy BMI and OW/OB is a strong predictor of offspring weight and BMI change from early life to adulthood.

Generational increase in obesity among young women: a prospective analysis of mother-daughter dyads.

BACKGROUND/OBJECTIVES: Increases in obesity in young adults over recent decades are shown by national survey data but have yet to be replicated using prospective data. We aim to quantify the increase in obesity and overweight over two generations of young adult women using prospective measures of body mass index (BMI). SUBJECTS/METHODS: Data are from the Mater University Study of Pregnancy (MUSP), a prospective pre-birth cohort study started in 1981 in Brisbane, Australia. Analyses were restricted to 992 mother-daughter dyads who were at similar ages at the time they were assessed and for whom measures of BMI were available. We also conducted an additional analysis to test whether there was a similar increase amongst father-son dyads. We used multinomial logistic regression for clustered data to compare the same prospective measures of BMI categories between mother and daughters. RESULTS: Controlling for a number of sociodemographic and lifestyle factors in the female sample, daughters had 5.04 (3.03, 8.85) times the odds of being obese and 2.54 (1.86, 3.54) times the odds of being overweight compared with their mothers. A large increase in obesity was also observed in the male sample. CONCLUSIONS: Using a longitudinal design to partly account for familial confounding of obesity risk factors, this study confirms a large and concerning increases in obesity rates over two generations of young adults and suggests increases in obesity over the past 20 years may be greater than previously anticipated.