If you indulged a few too many pregnancy cravings during your first and second trimesters, it's not too late to turn things around in the home stretch. In fact, the third trimester is the perfect time to get on track—the foods you eat now can impact your baby's health long after she's born, according to a study published in Cell.
Researchers found that offspring of mice that were fed a high-fat diet during lactation—the equivalent of the third trimester in humans—had an increased risk of being overweight throughout their lives. Why? The critters born to moms downing a fatty diet experienced changes in the hypothalamus, a part of the brain that regulates metabolism. This occurred whether the mama mice were plump or lean, meaning diet has an impact regardless of weight.
"The third trimester is a very important time in the development of your baby's metabolism," says Tamas Horvath, PhD, professor at the Yale University School of Medicine, and coauthor of the study. "It's when the brain develops connections associated with metabolic processes."
Don't worry: There's no need to trim the fat from your diet altogether. "Healthy fats are important in the third trimester to support your pregnancy and prepare for lactation," says Rebecca Scritchfield, R.D. and founder of Capitol Nutrition Group, which specializes in prenatal care. The key is focusing on fats that come from whole foods (like nuts, seeds, avocados, olive oil, eggs, salmon, yogurt and cheese), rather than the processed saturated and trans fats you'll find in packaged foods. "Whole foods supply vitamins and minerals, along with healthy fat," adds Scritchfield.