As moms, we’ve really been getting a talking-to lately about our diet and weight in pregnancy. Last year, for example, a large study in the Lancet showed a strong connection between a pregnant woman’s weight gain and the size of her baby (even factoring in the passing down of genes). Since birthweight is related to BMI later in life, clinicians and public health officials say this could be one piece of the obesity epidemic puzzle.
And this week, in the Proceedings of the National Academy of Sciences, Cambridge scientists reported on a study using a mouse model that showed a mom’s bad diet caused real changes to fetal development — ones that mimicked type 2 diabetes.
Here’s what they found (and why dad is not off the hook):
The researchers gave mouse moms either diets balanced for protein (a 20% protein diet), or low in protein (8%) — both with the same number of calories overall.
The moms fed the low protein diet had fetuses with compromised beta cells (a hallmark of type 2 diabetes, in which insulin-producing beta cells in the pancreas don’t function optimally). The production of a protein called Hnf4a in beta cells was reduced through “epigenetic” changes (this means changes in how a gene is expressed, not a change to the gene itself).
So an unbalanced diet in pregnancy can make small genetic changes that affect a baby’s metabolism.
But remember, we saw a similar experiment performed on mice dads, and the outcome was that a heavy dad with a poor diet upped the risk of type 2 diabetes for the offspring. So having a good diet for the future healthy of our babies isn’t just a mom’s responsibility.