You probably know that trans fat is bad news for your heart and waistline. But here's another reason why you should ban trans fat in your diet if you're breastfeeding: A new study published in the European Journal of Clinical Nutrition shows that mothers who consume a diet high in trans fats increase the likelihood that their infants will have high levels of body fat.

The University of Georgia researchers found that when breastfeeding women consume more than 4.5 grams of trans fats daily, their babies are twice as likely to have a high percentage of body fat (adiposity) compared with the babies of women who consume less than that amount.

Additionally, the study also found that mothers who consumed more than 4.5 grams of trans fats per day were almost 6 times more likely to gain body fat -- independent of their pre-pregnancy weight.

The team looked at different types of fat, but determined trans fats to be the most important contributor to excess body fat. "Trans fats stuck out as a predictor to increased adiposity in both mothers and their babies," said study co-author Alex Anderson, assistant professor in the UGA College of Family and Consumer Sciences.

Unfortunately, it's easy to consume too much trans fat if you're not careful: Just 1.5 tablespoons of stick margarine contain 4.5 grams of trans fat. The moral of the story, however, isn't to give up breastfeeding, which provides the best nutrition for your baby. It's about being doubly conscientious about eating a healthy diet when you're breastfeeding.

Reading the ingredient list on your food products is the first step you can take to weed out trans fat, say experts. Tell-tale ingredients that trans fat is present include "partially hydrogenated vegetable oils", "margarine", "vegetable shortening", "shortening" and "hardened vegetable oil". Products with these ingredients should be on your don't-buy list.