Effects of having a baby on weight gain.
BACKGROUND
Women often blame weight gain in early adulthood on having a baby.


OBJECTIVE
The aim was to estimate the weight gain attributable to having a baby, after disentangling the effects of other factors that influence weight change at this life stage.


METHODS
A longitudinal study of a randomly selected cohort of 6458 Australian women, aged 18-23 years in 1996, was conducted. Self-report mailed surveys were completed in 1996, 2000, 2003, and 2006, and data were analyzed in 2008.


RESULTS
On average, women gained weight at the rate of 0.93% per year (95% CI=0.89, 0.98) or 605 g/year (95% CI=580, 635) for a 65-kg woman. Over the 10-year study period, partnered women with one baby gained almost 4 kg more, and those with a partner but no baby gained 1.8 kg more, than unpartnered childless women (after adjustment for other significant factors: initial BMI and age; physical activity, sitting time, energy intake (2003); education level, hours in paid work, and smoking).


CONCLUSIONS
Having a baby has a marked effect on 10-year weight gain, but there is also an effect attributable to getting married or living with a partner. Social and lifestyle as well as energy balance variables should be considered when developing strategies to prevent weight gain in young adult women.
Brown
Wendy J
WJ
School of Human Movement Studies, University of Queensland, St. Lucia, Queensland 4072, Australia. wbrown@hms.uq.edu.au
Hockey
Richard
R
Dobson
Annette J
AJ
D000293:Adolescent; D000328:Adult; D001315:Australia; D015992:Body Mass Index; D005260:Female; D015438:Health Behavior; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D009035:Mothers; D036801:Parturition; D011247:Pregnancy; D015430:Weight Gain; D055815:Young Adult