The old saying that a pregnant woman should be eating for two – essentially doubling her food intake – was invalidated by experts some years ago.
Determining the Goldilocks “just right” amount of calories to consume during pregnancy can seem mystifying, but it is actually rather simple, said Dr. Priya Rajan, a professor of maternal-fetal medicine at Northwestern University in Chicago.
Three hundred calories of ice cream are not the same as calories derived from, say, high-fiber foods.
Dr. Priya Rajan, professor of maternal-fetal medicine, Northwestern University
Caloric Rule of Thumb
The chief determinant for caloric needs and appropriate weight gain during pregnancy is the weight -- specifically, body mass index, which indicates a person's fat ratio -- from which a woman starts when she becomes pregnant, Rajan said.
A pregnant woman’s age has no bearing on her caloric needs; a healthy 42-year-old woman has the same dietary needs as a healthy 22-year-old woman, Rajan said. For average-weight women in good health, an additional 350 calories a day is a wise rule of thumb, she said.
“That number can certainly be mitigated by conditions such as diabetes or by [carrying] twins,” Rajan added.
All calories are not equal, though, Rajan emphasized. “Three hundred calories of ice cream are not the same as calories derived from, say, high-fiber foods,” she said.
Appropriate Weight Gain
A woman should gain in the neighborhood of 25 to 30 pounds by the end of her pregnancy, Rajan said.
“You have lower weight-gaining goals if you are obese,” Rajan said. “For larger patients, I often recommend 15 pounds – no more.”
The National Institutes of Health advises pregnant women to gain weight gradually: two to four pounds during the first trimester, followed by three to four pounds per month for the second and third trimesters.
Foods to Avoid
Pregnant women experience more glucose, or sugar, intolerance, which contributes to conditions such as gestational diabetes. Doctors have seen a correlation between gestational diabetes and the overall rise of adult obesity in the United States, Rajan said. Recent studies also have indicated that a mother’s weight and nutrition may affect the child’s long-term risk for conditions such as heart disease and diabetes, Rajan said.
“[The data] is still evolving, but we are paying attention to it a little more and a little better,” Rajan said.
That does not mean that pregnant women must refrain from consuming sugar, Rajan added. “We generally tell women to eat a healthy, balanced diet,” she said.
During pregnancy, no foods are off-limits to healthy women for caloric reasons, said Rajan. The only foods women should abstain from include those that may expose them to toxins: foods such as unpasteurized milk, juice or soft cheese; raw or undercooked fish; high mercury-level fish; raw eggs or foods that contain raw eggs, such as cookie dough; store-prepared salads; raw shellfish; undercooked meats; and raw or undercooked sprouts.