In contrast to dietary fat, body fat stores are of tremendous
importance during physical activity, as long as the intensity is not too high and there is adequate O2 delivery to use fat as a fuel source.
Regarding the child, the
importance of the intrauterine and early postnatal environments for metabolic programming and modifications of the epigenome is increasingly recognised, 12 — 14 particularly for metabolic diseases such as obesity and diabetes.15 Thus, GDM is related to macrosomia at birth (> 4 kg), to excess body fat and (central) obesity and to insulin secretion in infants and children, the obesity being in part mediated by maternal body mass index (BMI) or birth weight.16 — 23 Intrauterine exposure to GDM also doubles the risk for subsequent type 2 diabetes in offspring compared with offspring of mothers with a high genetic predisposition for type 2 diabetes, but with normal glucose tolerance
during the index pregnancy.24 Maternal prepregnancy overweight and excessive gestational weight gain also predict high birth weight and adiposity
during infancy.12 25 This is highly relevant, as up to 60 % — 70 % of women with GDM are overweight or obese before pregnancy.26 Finally, maternal lifestyle behaviour such as a high fat diet or lack of
physical activity during pregnancy can influence offspring adiposity independent of maternal obesity.12 27