By: Rachel Neifeld, RD, CDN

The harmful effects of trans fats may extend beyond those it poses to adults, according to new research published in the American Journal of Clinical Nutrition. A study including nearly 1,400 pregnant women found that the higher a woman's intake of trans fats (chemically produced fats that are not beneficial to health) during the second trimester of pregnancy, the larger her newborn. This could lead to a larger-than-normal baby who may need to be delivered by C-section- a surgery that puts both mother and baby at higher risk of complications when compared to having a vaginal delivery. Larger-than-normal babies are also at increased risk of developing diabetes and heart disease later in life. 

This study is not conclusive- meaning that eating trans fats during pregnancy does not necessarily cause larger-than-normal babies, but only that there was an association between a baby’s birth weight and the mother’s consumption of trans fats. Whether or not trans fats have detrimental health effects on a newborn’s health, mothers’ should be avoiding this type of fat anyway as it is not good for anyone- regardless of age. 

Whereas we need some saturated fat and definitely unsaturated fats in our diet, we don’t need any trans fat. To produce trans fats, the structure of an oil is changed from its natural unsaturated form to a saturated one, making it solid at room temperature so that it becomes spreadable (some margarine and peanut butter) and have increased shelf life (baked goods).

The body doesn’t know what to do with these man-made trans fats so it makes sense that it probably won’t do anything well. In fact, this is the worst type of fat and it’s recommended that we keep trans fatty acid consumption as low as possible. Avoid a product if the ingredient list includes the words “partially hydrogenated.” Even if the label says “0 grams of trans fats,” if it’s partially hydrogenated it may have less than 0.5 grams per serving but this won’t be the case when more than one serving is consumed.

Don’t avoid all fat though, as it is very important that pregnant women get enough unsaturated fats including the essential fatty acids (omega 3 and omega 6 fats) that the body cannot produce on its own. These fats serve a wide variety of physiological functions in the body. Fat also aids in the absorption and transport of fat-soluble vitamins (A, D, E, and K) and other fat-soluble nutrients- so be sure to pour some olive oil over your salad to reap the benefits of your veggies! Examples of healthy fats include seeds, nuts, seeds, vegetable oils, and fatty fish (be sure to choose smaller, lower mercury fish such as salmon, light chunk tuna, and tilapia during pregnancy). 

Fat is a great source of energy so when you’re on the run and only have time for a quick energy-boosting snack, a fat-source is the perfect pick. Try peanut butter (non-hydrogenated) and apple, hummus and pita pieces, or a tasty trail mix including a mixture of almonds, seeds, and dried fruit. Both your and you’re baby’s health will benefit from banning trans fats from your diet.

Source: American Journal of Clinical Nutrition https://academic.oup.com/ajcn/article/94/5/1241/4597860