"I applaud Salma and anyone who has the courage to breastfeed in the fishbowl celebrity environment," wrote another commenter who has nursed two children, but found it harder to lose the weight with the third child.
"Your metabolism changes," she said. "My advice: Eat the healthiest diet possible, exercise as much as possible, and not worry about it so much."
At least one study has shown that despite myriad benefits for mothers and their babies, breastfeeding — contrary to popular belief — does not help shed the pounds faster. In a study published by The American Journal of Clinical Nutrition in 2004, researchers concluded that non-breastfeeding women actually lose body fat faster than nursing mothers.
"Body composition changes occur differently in non-lactating and lactating women during the first six months postpartum and occur at some body sites until 12 months postpartum despite previous lactation status," reported researchers at Children's Hospital Medical Center in Cincinnati. "This data agrees with those from previous reports that trunk fat and thigh fat are the primary energy depots mobilized to support lactation."
The six-month study looked at 326 new mothers and measured their body changes after delivery. What researchers failed to ask was whether non-nursing mothers had intentionally — as Hayek suggested — restricted their diets to lose weight.
The Cincinnati medical team found that body composition can change quickly after delivery. In the first six months after giving birth, 81 of the nonbreastfeeding mothers lost fat from their whole body, arms, and legs faster than the 87 breastfeeding moms. In addition, the lactating women gained fat in their arms.
A change in body composition was determined by imaging the whole body and determining fat and muscle mass. They found both groups lost weight at similar rates and decreases in body weight was not influenced by breastfeeding.
The hormone prolactin stimulates appetite and aids in milk production in breastfeeding mothers, according to the study, which could account for the extra calories. Also, non-nursing mothers reported more physical activity than nursing ones.
Surprisingly, after one year, the body weight and percentage of fat in the two groups of women was equal.
These findings support anecdotal evidence from lactation experts, who say it takes about one year to regain the pre-pregnancy figure. The key is whether a woman is at a normal and healthy weight before getting pregnant. Most doctors recommend a weight gain of 20 to 25 pounds.
Nancy Clark, a certified lactation consultant from Northern Virginia, said that breastfeeding does, indeed, make a difference. She has worked with nursing mothers for 22 years and said nursing women tend to be more conscious of their health — not drinking alcohol or smoking and paying attention to their food choices. But it's more than that.
"It takes calories when you make milk, and with a reasonable diet of unprocessed food, you can lose weight," she said.
Nursing a baby has multiple benefits for overall health, according to Clark. It shortens bleeding time, preventing post-partum anemia; releases oxytocin to make the uterus contract and return to its normal size; and helps the body rid itself of excess fluids carried during pregnancy.