Pregnancy Nutrition Guide: What to Eat and What to Avoid

Updated April 2026 · By the BabyCalcs Team

Pregnancy nutrition is surrounded by conflicting advice, cultural myths, and anxiety-driven food avoidance lists that make eating feel like navigating a minefield. The evidence-based reality is simpler: eat a varied diet, increase calories modestly in the second and third trimesters, ensure adequate intake of a few critical nutrients, and avoid a short list of genuinely dangerous foods. This guide separates the science from the folklore so you can nourish yourself and your baby without unnecessary stress.

Calorie Needs by Trimester

The first trimester requires no additional calories above your pre-pregnancy intake. The baby is smaller than a lemon, and calorie needs have not meaningfully increased. In the second trimester, add approximately 340 calories per day. In the third trimester, add approximately 450 calories per day.

These are modest additions. An extra 340 calories is a cup of Greek yogurt with granola and berries, not an entire extra meal. The eating-for-two myth leads to excessive weight gain that increases the risk of gestational diabetes, preeclampsia, cesarean delivery, and postpartum weight retention. Eat for one and a quarter, not two.

Critical Nutrients: What You Need More Of

Folate (folic acid) is the most critical nutrient in early pregnancy. It prevents neural tube defects, and adequate intake must begin before conception. The recommendation is 400-800 micrograms daily from supplements plus food sources (leafy greens, fortified cereals, legumes). All prenatal vitamins include folate.

Iron needs nearly double during pregnancy to support increased blood volume and fetal development. The target is 27 milligrams per day, which is difficult to achieve from food alone. Red meat, spinach, beans, and fortified cereals are good sources. Prenatal vitamins bridge the gap. DHA (an omega-3 fatty acid) supports fetal brain and eye development. The target is 200-300 milligrams daily from fatty fish (2-3 servings per week) or a DHA supplement.

• Folate: 400-800 mcg/day (neural tube development)
• Iron: 27 mg/day (blood volume and oxygen delivery)
• DHA: 200-300 mg/day (brain and eye development)
• Calcium: 1,000 mg/day (skeletal development)
• Vitamin D: 600 IU/day (calcium absorption, immune function)
• Iodine: 220 mcg/day (thyroid function and brain development)

Foods to Avoid: The Evidence-Based List

The genuinely dangerous foods during pregnancy are those carrying a meaningful risk of Listeria, Toxoplasma, or mercury exposure. Raw or undercooked meat, poultry, and eggs carry infection risk. Unpasteurized dairy and soft cheeses (brie, camembert, queso fresco from unpasteurized milk) can harbor Listeria.

High-mercury fish should be limited: shark, swordfish, king mackerel, and tilefish. Low-mercury fish like salmon, shrimp, sardines, and cod are safe and beneficial at 2-3 servings per week. Deli meats carry a small Listeria risk; heat them until steaming to reduce it. Alcohol has no established safe level during pregnancy and should be avoided entirely.

Weight Gain Targets

The Institute of Medicine guidelines for total pregnancy weight gain depend on pre-pregnancy BMI. Underweight (BMI under 18.5): 28-40 pounds. Normal weight (18.5-24.9): 25-35 pounds. Overweight (25.0-29.9): 15-25 pounds. Obese (30+): 11-20 pounds.

Most weight gain occurs in the second and third trimesters at a rate of about 1 pound per week for normal-weight women. Weight gain below the recommended range increases the risk of preterm birth and low birth weight. Weight gain above increases the risk of gestational complications and makes postpartum weight loss harder. Regular weigh-ins at prenatal visits track your trajectory.

Managing Nausea and Food Aversions

Nausea affects 70-80 percent of pregnancies, typically from week 6 through week 12-14. Eating small, frequent meals (every 2-3 hours) prevents the empty stomach that worsens nausea. Bland, starchy foods like crackers, toast, and plain rice are often tolerated best. Ginger (ginger ale, ginger chews, ginger tea) has evidence supporting its anti-nausea effect.

If nausea prevents adequate nutrition, talk to your provider about vitamin B6 (25 mg three times daily) and doxylamine (Unisom SleepTabs), which is an FDA-approved combination for pregnancy nausea. Severe nausea with inability to keep fluids down (hyperemesis gravidarum) requires medical treatment. Do not tough it out if you cannot stay hydrated.