Mediterranean diet during pregnancy reduces the risk of childhood obesity

New research shows that following a Mediterranean diet while pregnant can prevent childhood obesity, and that gene-related effects may play a role in long-term health outcomes.

Study: Effects of the Mediterranean diet during pregnancy on the onset of overweight or obesity in the offspring: a randomized trial. Image Credit: Alex Maryna / Shutterstock.com

In a recent study published in The International Journal of Obesityresearchers investigate the effects of nutritional counseling promoting a Mediterranean diet (MD) during pregnancy on the likelihood that children born to these mothers will be obese or overweight by age two.

The influence of maternal diet on childhood obesity

The rise in childhood obesity is a significant public health issue worldwide and, as a result, strategies need to be implemented to prevent health problems later in life. Early life, including pregnancy, is a key period to prevent obesity, as the mother’s diet can influence the future health of the child.

The MD, which is rich in fiber, antioxidants and healthy fats, is known for its benefits in preventing overweight in adulthood. During pregnancy, the MD may protect children from developing obesity through its potential effects on the regulation of certain genes.

However, there is still a lack of evidence as to whether following MD during pregnancy could prevent overweight and obesity in early childhood. Although some observational studies have been conducted, experimental research is needed to understand these associations.

About the study

The MD during Pregnancy (PEMEDI) trial was designed to examine whether women who followed MD during pregnancy could prevent obesity or overweight in their children under two years of age. A total of 104 pregnant women were randomized to receive standard care alone or standard care plus personalized MD counseling.

Women assigned to the MD group attended three dietary counseling sessions during pregnancy. MD recommendations included eating more vegetables, fruit, whole grains, fish and legumes, using olive oil, and avoiding processed foods.

The primary study outcome was the proportion of children who were obese or overweight at two years of age. Secondary outcomes included maternal adherence to the MD and weight gain during pregnancy.

The researchers also measured changes in gene expression, focusing on the leptin gene, which is linked to weight regulation. Follow-up assessments were carried out on the children every few months until their second birthday. Statistical analysis was performed to compare results between the two groups.

Results of the study

Following MD during pregnancy reduced the likelihood of children being overweight or obese by two years of age. In the MD group, no children were obese, and 6% were overweight, compared to 8% and 22% of children who were obese and overweight in the control group, respectively.

The absolute difference in risk, defined as the mean risk in the control group minus the mean risk in the treatment group, was significant. For that, the number needed to treat (NNT) was four, indicating that for every four women who followed the MD, one case of childhood obesity or overweight was prevented.

Maternal weight gain during pregnancy was the same in both groups, indicating that the MD did not affect weight gain. Babies born to mothers in the MD group had slightly higher birth weights compared to those in the control group.

Further analysis revealed that the MD was associated with higher methylation of the leptin gene promoter. Therefore, the MD may influence gene expression related to weight regulation in the offspring.

Conclusions

The results of the study underline the importance of the mother’s diet in preventing childhood obesity, as the risk of obesity or overweight in children appears to be reduced after MD during pregnancy.

One of the main strengths of the current study is the experimental design, which provides strong evidence compared to previous observational studies with mixed results. The researchers also explored possible underlying mechanisms, including changes in the leptin gene, that may explain how MD affects obesity risk.

However, significant limitations of the current study include the small sample size and the limitation of the genetic analysis to a few samples, which may affect the generalizability of the findings. Additional limitations include the inability to blind participants and the lack of other MD adherence biomarkers.

Future research should include larger trials with more diverse populations and explore additional biomarkers of MD adherence. Additional studies are also needed to determine the long-term consequences of continuing MD during pregnancy on obesity and other health outcomes later in childhood and adulthood.