The impact of maternal cafeteria diet on anxiety-related behaviour and exploration in the offspring

Contemporary trends in obesity mean that research into whether unbalanced diets could impact on behavioural traits became increasingly important. The timing of exposure to obesity is particularly important, as sensitive periods during development have been identified where dietary extremes play a critical role in determining adult risk of physiological dysfunction. To this end, female Wistar rats were fed on chow or cafeteria diet (CD) for 8 weeks from weaning until mating. Half of the mated animals within each group were crossed-over to the alternative diet. This generated four treatment groups, differing in their pre-gestational and gestational diets. After birth, offspring of dams from each of the 4 pregnancy groups were further divided into groups, either being fed chow or CD throughout lactation. Anxiety-related behaviour and exploration in the offspring were tested in the Elevated Plus Maze (EMP) and the Open Field (OF) at 10 weeks of age. Maternal obesity significantly reduced the EPM locomotor activity in male and female offspring and grooming in males. Lactational CD had an anxiolytic effect in male offspring as shown in the EPM (increased entries into and more time on open arms) and the OF (shorter latency to enter the centre). In both sexes, lactational CD reduced grooming upon exposure to the EPM and the OF. Post mortem analysis revealed a stimulant effect of lactational CD on adipose tissue growth. The present study demonstrates that pre-gestational, gestational and lactational maternal CD programme behaviour in the offspring with lactational CD reducing anxiety in the male offspring.

Research Highlights
► Hyperenergetic maternal diet and / or obesity impact on behaviour in the offspring.
► The most influential period for such a behavioural programming is lactation.
► Lactational hyperenergetic diet reduces anxiety in male offspring.