Pregnancy Nutrition by Trimester: What to Eat and When
Your nutritional needs shift as your pregnancy grows, and it helps to know what to focus on when. This is the big-picture map, trimester by trimester, with links to the detailed guides for each stage and nutrient. None of it needs to be perfect, a varied diet plus a good prenatal covers most of it.
The one constant across all three trimesters: a good prenatal vitamin with folate, iron and ideally DHA. It quietly covers the gaps on the days your diet can't.
First trimester: survival mode (weeks 1–13)
Right now it's less about perfect nutrition and more about folate and simply keeping food down. Folate is critical for your baby's neural tube, which forms very early, and nausea can make eating hard. Be kind to yourself and eat what stays down.
Second trimester: the golden window (weeks 14–27)
Appetite usually returns and energy picks up, a great time to build good habits. Focus shifts to iron (your blood volume is climbing), calcium for your baby's bones, and steady protein.
Third trimester: fuelling the final stretch (weeks 28–40)
Your baby is growing fast and gaining weight, so protein, iron and steady energy matter most, while smaller, more frequent meals help with the heartburn and squeezed stomach many feel now.
The key nutrients, and where to get them
- Folate, neural development. See folate-rich foods.
- Iron, blood volume & energy. See iron-rich foods.
- Calcium, baby's bones. See calcium sources.
- Protein, growth. See high-protein foods.
- DHA (omega-3), brain & eyes. Best from oily fish, see the seafood in pregnancy guide, or a prenatal that includes it.
Wondering whether a specific food is safe at any stage? Use our A–Z food checker for an instant verdict on 800+ foods. Not sure exactly how far along you are? Our free due date calculator tells you your trimester and how many weeks to go.
Frequently Asked Questions
What should I eat in each trimester of pregnancy?
In the first trimester, focus on folate and simply keeping food down. In the second, add iron, calcium and protein as your appetite returns. In the third, prioritise protein and steady energy with smaller, frequent meals. A prenatal vitamin supports all three.
What are the most important nutrients during pregnancy?
Folate (neural development), iron (blood volume), calcium (baby's bones), protein (growth) and DHA omega-3 (brain and eyes). A varied diet plus a prenatal vitamin covers most needs.
Do I need to eat differently in each trimester?
Your needs shift gradually rather than dramatically. The biggest change is often practical: nausea in the first trimester and a squeezed stomach in the third both favour smaller, simpler meals.
How many extra calories do I need?
Not many early on. Roughly 340 extra calories a day in the second trimester and 450 in the third, according to common guidance - but quality matters more than counting. Ask your provider about your situation.
Sources: NHS, CDC, ACOG, FDA.
How we review: Written by the PregnancySafeFoods editorial team and checked against official guidance. Our editorial policy.
Educational information only, not medical advice. Always consult your own healthcare provider.
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