Harvard University Health Services

3c. Diet Information

If you gain more than 3-4 lbs. per month, you are probably eating more than you need. A steady rate of weight gain is the goal. As a general guide, 2 to 5 pounds (1 to 2.3 kg) is gained during the first trimester. Weight gain during the second and third trimester is about one pound (0.5 kg) per week.

Many people will encourage you to eat enough for two. The goal is not to eat more, but to select foods carefully.
  • Avoid excess fats, sweets and alcohol.
  • Eat fresh fruits and vegetables and whole grains.
  • Diet drinks or foods containing saccharine (Equal, Sweet 'n Low) should not be consumed.
  • Limit foods containing aspartame (Nutra Sweet) to 2 servings or less a day.
  • Avoid shark, swordfish, king mackerel, tilefish; they contain high levels of methylmercury.
  • Avoid all non-pasteurized dairy products including soft cheeses such as feta, brie and goat cheese.

The best guide to adequate nutrition is a balanced diet and weight gain. The following diet is balanced. Actual food choices may vary widely according to tastes and desired weight gain.
  • 2-3 servings of dairy products - milk, cheese, yogurt or other calcium-rich foods.
  • 2–3 servings meat, poultry, fish, eggs, cheese, beans, nuts, yeast
  • 2-4 servings of fruits (1-2 servings of fruit or juice rich in Vitamin C)
  • 3-5 servings of vegetables ( 1 serving of Vitamin A rich vegetable)
  • 6-11 servings of whole-grain products - breads, cereals, rice
  • Fats, oil, sweets – amounts to meet caloric needs

A prenatal vitamin supplement will provide extra iron and folate required during pregnancy. It may darken the color of your stools or cause constipation. Remember that prenatal vitamins are not a substitute for a nutritious diet. Prior to your first visit you may use prenatal vitamins available commercially, without a prescription. Avoid excessive intake of vitamins.

A few more things to consider:
  • Alcohol should not be consumed when you are pregnant.
  • Caffeine, a central nervous system stimulant, crosses the placenta and enters the fetal bloodstream. You should limit sources of caffeine to two or fewer servings per day.
  • The safety of herbal teas is unknown. You should use only those in filtered tea bags and limit consumption to two 8-oz servings daily.

Cravings
It’s important to keep eating your balanced diet, no matter what your cravings are.  If you feel like eating a pot of spinach at 2:00 a.m., go ahead.  But if you feel like eating hot chili or a half dozen of your favorite candy bars … that’s another issue.  A desire to eat strange foods or non-food items might mean a nutritional deficiency that needs correcting.

Pica is the medical term for the unusual cravings for non-food items such as clay or laundry detergent that you might have while you are pregnant.  No one knows why this happens, but some women experience it, and ingesting it can be harmful.