Long thought to be harmful to the mother and baby, increasing evidence shows that exercise is healthy and important during pregnancy. Recent research shows that exercise during pregnancy provides crucial health benefits to the baby: metabolic health.
A 2022 study showed that by exercising during pregnancy, mothers can improve the baby’s long-term metabolism, even if the mother is obese or eating a high-fat diet. Physical exercise by the mother causes the placenta to secrete the key protein SOD3, resulting in a lowered risk of diabetes for the offspring. The findings in the paper identified the mechanisms behind this process.
A Worrying Trend: Obese and Pregnant
Maternal obesity and type 2 diabetes are on the rise. Over 30% of women of childbearing age in Western and Asian countries are classified as obese. The number of women who were obese before their pregnancy increased to 29% in 2019. Meanwhile, 630 million people are expected to be living with type 2 diabetes by 2045.
Children born to obese mothers or mothers with type 2 diabetes have an increased risk of diabetes, even after going on to live healthy lives. They are at greater risk for having a metabolic disorder and becoming obese themselves.
“With the growth of maternal obesity, a worrying cycle is forming where the risks of diabetes gets passed down from generation to generation,” says assistant professor Joji Kusuyama from Tohoku University’s Interdisciplinary Institute for Frontier Sciences (FRIS), and lead author of the study. “Stopping this cycle is a critical and pressing medical problem.”
Previously, the group showed that exercise during pregnancy has tremendous benefits on an offspring’s metabolic health, demonstrating that placenta-derived SOD3, which stands for supuroexide dismutase 3, plays a key role in transmitting the benefits of maternal exercise to the baby. Building on this, the team set out to understand how SOD3 prevents the negative effects of obesity being passed from mother to child and found that SOD3 inhibited high-fat diet-induced abnormalities in the offspring’s glucose metabolism.
High Fat Diet During Pregnancy
Eating a high-fat diet during pregnancy impacts the baby. This makes it much more likely that the baby will become overweight or obese, as the mother’s diet effects glucose metabolism genes. For a more technical explanation, a high-fat diet during pregnancy means the histone H3 trimethylation H3K4me3 is decreased in the liver and hinders the expression of glucose metabolism genes.
Yet, exercising during pregnancy reverses the impact of a high-fat diet, ensuring that the baby will not inherit a metabolism already prone to obesity and metabolic disorder. Genetic manipulation demonstrated that placental SOD3 is indispensable for the protective effects of maternal exercise on offspring.
Is Childhood Obesity Genetic?
Maternal obesity and diet during pregnancy significantly influence a child’s risk of developing obesity. Research shows that children born to mothers who are obese before or during pregnancy are more likely to become overweight or obese themselves. This increased risk is due not only to shared genetics but also to changes in the intrauterine environment that affect the child’s metabolism, appetite regulation, and fat storage mechanisms.
Poor maternal nutrition—such as diets high in sugar, unhealthy fats, and processed foods—can lead to fetal programming changes. These changes may alter how a child’s body manages energy and fat, increasing the likelihood of weight gain later in life. Additionally, excess maternal weight is associated with higher levels of inflammation and insulin resistance during pregnancy, which can also negatively impact fetal development and promote obesity.
Breastfeeding and early infant feeding practices are also influenced by maternal health. Mothers with obesity are statistically less likely to initiate or continue breastfeeding, and formula feeding has been linked to a slightly higher risk of childhood obesity. Furthermore, maternal behaviors around food—such as feeding styles and attitudes toward nutrition—can shape a child’s lifelong eating habits.
Implications for the Future
Given the simplicity and cost-effectiveness of exercise, encouraging mothers to exercise could help reverse the alarming rates of obesity and type-2 diabetes. The merits of SOD3 may not be limited to the metabolism stresses, says Kusuyama. “There may be wider benefits of this protein on other organs in the child. We are currently looking into the modifications in placenta tissue brought about by SOD3 that may have positive lifelong impacts on children.” Exercise may have greater benefits for the baby than just lowering the risk of childhood obesity and diabetes. This study did not review those other possible advantages.
The authors caution the study is only at the preclinical stage and its applicability to humans requires further studies. Additionally, certain aspects of the signaling pathway require further investigation.
References:
* Godfrey, K. M., et al. (2017). Influence of maternal obesity on the long-term health of offspring. *The Lancet Diabetes & Endocrinology*, 5(1), 53–64. [https://doi.org/10.1016/S2213-8587(16)30107-3](https://doi.org/10.1016/S2213-8587%2816%2930107-3)
* Rivera, H. M., Christiansen, K. J., & Sullivan, E. L. (2015). The role of maternal obesity in the risk of neuropsychiatric disorders. *Frontiers in Neuroscience*, 9, 194. [https://doi.org/10.3389/fnins.2015.00194](https://doi.org/10.3389/fnins.2015.00194)
* World Health Organization (WHO). (2023). *Report of the Commission on Ending Childhood Obesity*. [https://www.who.int/publications/i/item/9789241510066](https://www.who.int/publications/i/item/9789241510066)
