Nutrition Science and Everyday Application - beta v 0.1

576 ALICE CALLAHAN, PHD, HEATHER LEONARD, MED, RDN, AND TAMBERLY POWELL, MS, RDN
Macronutrient Requirements
The Acceptable Macronutrient Distributions Ranges (AMDR) for macronutrients are the same
for all healthy adults, pregnant or not, with about 45 to 65 percent of calories coming from
carbohydrates, 20 to 35 percent from fats, and 10 to 35 percent from protein. As energy
intake increases, a pregnant woman needs more of each of these macronutrients.
The RDA for carbohydrates increases from 130 grams per day for non-pregnant adults to
175 grams per day for pregnant women. This level of carbohydrate intake provides energy
for fetal development and ensures adequate glucose for both the mother’s and the fetus’s
brain. The recommended fiber intake in pregnancy, expressed as an AI, is the same as
for all adults: 14 grams of fiber per 1,000 calories consumed. As caloric intake increases
during pregnancy, so should fiber intake, emphasizing the importance of choosing whole
food sources of carbohydrates.
Additional protein is also needed during pregnancy. Protein builds muscle and other
tissues, enzymes, antibodies, and hormones in both the mother and the fetus, as well
as supporting increased blood volume and the production of amniotic fluid. The RDA for
protein during pregnancy is 1.1 grams per kg body weight per day, coming to about 71 grams
per day for an average woman—roughly 25 grams more than needed before pregnancy. 1
There is not a specific RDA for fat during pregnancy. Fats should continue to make up 25
to 35 percent of daily caloric intake, providing energy and essential fatty acids (linoleic acid
and alpha-linolenic acid), as well as helping with fat-soluble vitamin absorption. The omega-3
polyunsaturated fatty acids DHA and EPA become more important during pregnancy and
lactation, because they are essential for brain and eye development of the fetus and infant.
The Dietary Guidelines for Americans recommend that pregnant women consume 8 to 12
ounces of seafood each week, in part to provide omega-3 fatty acids. Fish with high levels
of mercury should be avoided; these include king mackerel, marlin, orange roughy, shark,
swordfish, tilefish, and bigeye tuna. 11-12