Background and aim: Motherhood is a predictor of obesity, however little is understood about how dietary and psychological factors might contribute to long-term weight gain amongst mothers. The aim of the current study was to track the weight of Australian mothers over an 8-year period. In addition, daily fruit and vegetable intake, frequency of alcohol consumption per day, and depressive symptoms were examined as predictors of maternal weight gain. Method: The Body Mass Index (BMI; kg/m2) of1,470 first-time Australian mothers from the baby-cohort from the Longitudinal Study of Australian Children (LSAC) database were analysed across 5 waves of data, each two years apart. A multi-level mixed model regression was used to examine whether fruit and vegetable intake, alcohol consumption, and depressive symptoms were predictors of changes in maternal BMI while also controlling for maternal age, and social economic position (SEP) at Wave 1, and parity at each time-point. Findings: At Wave 1, mothers were on average 31-years-old.Over the 8-year period, maternal BMI showed an initial decrease (between Wave 1 and 2), and then significantly increased over time (from Waves 3, 4 and 5). Maternal weight gain was inversely predicted by both daily fruit consumption and SEP. Conclusion: Maternal weight tracks upwardly overtime. Higher fruit intake (which may be a proxy indicator of overall diet quality), appears to be protective factor against maternal weight gain. In contrast, women from a lower socioeconomic background are more at risk of weight gain, suggesting that resources, supports and interventions need to target the needs of this group of women.