• birthweight;
  • maternal body mass index;
  • maternal dietary behaviors



A high infant birthweight is associated with future risk of a range of adverse health consequences. This study sought to determine whether maternal “junk food” diet (energy-dense, nutrient-poor) predicts high birthweight in first-time mothers in southwest Sydney, Australia.


A community-based longitudinal study was conducted with a total of 368 first-time mothers and their newborns. Information about maternal “junk food” diet, including high consumption of soft drink, fast food, and/or processed meat and chips, and self-reported prepregnant weight and height of first-time mothers was collected by a face-to-face interview with mothers between 24 and 34 weeks of pregnancy. Birthweight was measured in hospital and reported by the mother, together with gestational age, when the baby was 6 months old. Logistic regression modeling was used to determine the factors predicting birthweight greater than 4.0 kg.


Eleven percent of newborns weighed more than 4.0 kg (12% boys, 9% girls). Compared with mothers who had a “junk food” diet, mothers who had not consumed “junk food” during pregnancy were significantly less likely to have a newborn weighing more than 4.0 kg, with adjusted odds ratio (AOR) 0.36, 95 percent confidence interval (CI) 0.14–0.91, = 0.03, after adjusting for maternal weight status and gestational age. Compared with healthy and underweight mothers, overweight or obese mothers were more likely to have a newborn weighing more than 4.0 kg (AOR overweight 3.03, 95% CI 1.35–6.80; obese 3.79, 95% CI 1.41–10.25) after allowing for “junk food” diet and gestational age.


Maternal “junk food” diet during pregnancy and prepregnant overweight and obesity were independent predictors of high infant birthweight. Early childhood obesity interventions should consider addressing these factors. (BIRTH 40:1 March 2013)