Manager, Nutrition Services
Joslin Diabetes Center
The old adage says you are eating for two during pregnancy, but I like to phrase it as you are eating for the health of yourself and your child. You need to provide your body with the nutrients it most needs because your fetus gets its nourishment from your body.
Pregnancy puts extra demands on the body: you have to have enough calories and protein to support the extra tissue that makes up the lining of the uterus and the placenta, as well as to supply energy for the growth of your baby. Consuming too few calories and gaining too little weight can lead to preterm delivery or babies who are small for their gestational age. There may also be long-term consequences, such as learning disabilities for the child later on.
On the other hand, eating too many calories can result in obesity and gestational diabetes for you, and obesity, difficulties in delivery and possible hypoglycemia at birth for the baby, as well as an increased risk of obesity for the child later in life.
Extra calorie needs during pregnancy are quite modest. Women need approximately 300 extra calories during the second and third trimesters of pregnancy. In addition, they need about 10 extra grams of protein. Three cups of 1 percent milk provide more than double the protein and all the needed extra calories.
On the micronutrient level, which refers to your vitamin and mineral intake, pregnant women need additional calcium, folic acid and iron. Calcium helps support the baby’s skeletal structure and the extra weight of pregnancy. Folic acid is needed to prevent neural tubular defects, and iron allows for the expanded blood volume.
Folate is found in green leafy vegetables such as spinach, bok choy and kale, as well as in oranges. Good sources of calcium are milk, yogurt, cheese, many leafy green vegetables, legumes and canned fish with bones. Iron sources include red meats, beans, dried fruits and fortified cereals.
The other big nutritional changes for pregnancy are things to avoid: all alcohol; cold cuts and unpasteurized foods to reduce the chance of listeria; and shark, swordfish, king mackerel and tilefish because they contain high levels of mercury. Also, reduce caffeine intake to less than 200 milligrams a day, the amount in a small coffee or a 12-ounce diet soda.