8. Bigger calorie burn
You may have heard that breastfeeding burns an extra 400 to 500 calories a day. And that’s almost right. “Breastfeeding doesn’t burn calories, but it does use them,” Lawrence explains. “Breast milk contains 20 calories per ounce, so if you feed your baby 20 ounces a day, that’s 400 calories you’ve swept right out of your body.”
9. A green machine
Dairy cows, which are raised in part to make infant formula, are a significant contributor to global warming: Their belching, manure and flatulence (really!) spew enormous amounts of methane, a harmful greenhouse gas, into the atmosphere. “Plus, most formula companies don’t purchase milk from American farmers, so they’re not even helping our economy,” Lawrence says.
10. A customized food supply
Whereas formula isn’t able to change its constitution, your breast milk morphs to meet your baby’s changing needs. Colostrum—the “premilk” that comes in a day or two after you deliver—is chockfull of antibodies to protect your newborn baby. “It’s also higher in protein and lower in sugar [than ‘full’ milk], so even a small amount can hold off your baby’s hunger,” says Heather Kelly, an international board-certified lactation consultant in New York City and a member of the Bravado Breastfeeding Information Council’s advisory board. When your full milk comes in (usually three to four days after delivery), it is higher in both sugar and volume than colostrum—again, just what your baby requires. “He needs a lot of calories and needs to eat frequently to fuel his rapid growth,” Kelly explains. “Your mature milk is designed to be digested quickly so he’ll eat often.”
11. More vaccination protection
Research shows that breastfed babies have a better antibody response to vaccines than formula-fed babies.
12. Fewer sick days
Since your baby will be ill less often, that means less missed work for you.
13. A vacation from your period
Breastfeeding your baby around the clock—no bottles or formula—will delay ovulation, which means delayed menstruation. “Breastfeeding causes the release of prolactin, which keeps estrogen and progesterone at bay so ovulation isn’t triggered,” Kelly explains. “When your prolactin levels drop, those two hormones can kick back in, which means ovulation—and, hence, menstruation—occurs.”
Even if you do breastfeed exclusively, your prolactin levels will eventually drop over the course of several months. Many moms who nurse exclusively get their first period somewhere between six and eight months after having a baby, Kelly adds; others don’t for a full year. Another benefit in the green category: Fewer periods mean fewer sanitary products in landfills.