Pregnancy and breastfeeding: omega-3 to avoid excess weight in children?

The intestinal flora of babies is said to influence their overweight status and be dependent on the dietary habits of the mother. The risk of excess weight in the child can be strongly impacted by the balance between omega-3 and omega-6  intake during pregnancy and breastfeeding.


What if the fight against childhood obesity involved the mother’s diet? The equilibrium of the intestinal flora is influenced by what’s on the menu. But according to a study conducted by American and Irish researchers, the risk of excess weight is determined from pregnancy. To reach this conclusion, the scientists conducted experiments on different lines of mice and their offspring. The aim was to understand the benefits of maternal intake of omega-3 (fatty fish, nuts…) and omega-6 (vegetable oils, avocado…) for the intestinal flora of baby mice and their weight gain.

Males gained less weight

The mothers of the first group followed a diet containing equal levels of omega-6 and omega-3. The second group received the equivalent of our Western diet, much richer in omega-6. After birth, some of the baby mice were suckled by mothers from the other group to see if this affected the composition of the microbiota of the little mouse. Result: transmission of maternal omega-3 during gestation and suckling significantly reduced weight gain in male baby mice over time. Conversely, no influence was observed in the females.

Suckling is the key to the process

Suckling is thought to be the key step in the formation of the intestinal flora. Among the animals who “changed” mother, those that were suckled by a mouse that consumed equal levels of omega‑3 and omega-6 had the most balanced microbiota. The scientists consider that this could be explained by direct transmission of good bacteria via the mother’s milk. What is the explanation for these fatty acids having such an effect on weight gain? The nutrients transmitted by the umbilical cord and the mother’s milk could limit the accumulation of fats. Omega-3 is also thought to reduce inflammation, a well-known risk factor for obesity. It would therefore have a long-term beneficial action, by promoting the integrity of the intestinal barrier, the presence of “good” bacteria and an absence of inflammation. Something to encourage us to eat more salmon, pine nuts and hazelnuts!



Robertson RC, Kaliannan K, Strain CR, Ross RP, Stanton C, Kang JX. Maternal omega-3 fatty acids regulate offspring obesity through persistent modulation of gut microbiota. Microbiome. 2018 May 24;6(1):95