This study investigates the effect of maternal diet-induced obesity in mice on maternal and offspring (male and female) nutrient intake, growth and adiposity, and investigates the effects of maternal diet on the behaviour of male and female offspring in four tasks. Figure 1 describes the nutrient intake of pre-pregnant, pregnant and lactating mice on a control versus a high fat and high sugar (HFHS) diet (mean and SD across cages). Figure 2 describes the body weight (mean and SD), the fat mass (individual mice) and lean mass (individual mice) of pre-pregnant, pregnant and lactating mice on a control versus a HFHS diet. Figure 3 describes the body mass and fractional growth rate of the male and female pre-weaning offspring (2 to 21 days of age) of mothers on the control versus HFHS diet. Figure 4 describes the nutrient intake of the male and female offspring, after weaning (21 to 91 days of age) of mothers on the control versus HFHS diet. Figure 5 describes the body weight (mean and SD), fractional growth rate (mean and SD) and fat & lean masses (individual mice) in the male and female offspring, after weaning (21 to 91 days of age) of mothers on the control versus HFHS diet. Figure 6 describes 4 measures of anxiety-related behaviour in the elevated plus maze by male and female offspring of mothers on the control versus HFHS diet. Figure 7 describes 4 measures of cognitive behaviour in the novel object recognition task by male and female offspring of mothers on the control versus HFHS diet. Figure Supplementary 2 describes 4 measurements of locomotion and anxiety-related behaviour int he open field task by male and female offspring of mothers on the control versus HFHS diet. Figure Supplementary 3 describes 2 measures of social preference behaviour of male and female offspring of mothers on the control versus HFHS diet. Table 1 gives all of the body weights, organ weights and fat deposit weights measured in this study in the pre-pregnant, pregnant and lactating female mice and int he male and female offspring.