Pregnancy nutrition by trimester: what actually changes
Your energy and nutrient needs shift as pregnancy progresses. Here's the trimester-by-trimester picture — no extra calories in T1, about +340 in T2, +452 in T3.
The short version
You are not “eating for two” in the sense of doubling your food. Energy needs stay about the same in the first trimester, then rise modestly: roughly +340 kcal a day in trimester 2 and +452 kcal a day in trimester 3. Nutrient needs — especially folate and iron — rise more than calories do.
Trimester 1: quality over quantity
Your baby is tiny, and your energy needs haven’t really changed yet. Nausea and food aversions are common, so aim for foods you can keep down and cover the essentials. Folate matters most now — around 600 mcg a day — to support neural-tube development, which is why folic acid supplements are recommended before and in early pregnancy.
Trimester 2: about +340 kcal a day
As your body builds tissue and blood volume, energy needs rise by roughly 340 kcal — about a substantial snack or small extra meal. This is established science, not a guess. Iron becomes a headline nutrient as your blood volume expands; needs rise toward ~27 mg a day.
Trimester 3: about +452 kcal a day
Growth accelerates and energy needs rise a little further, to about +452 kcal a day. Smaller, more frequent meals often feel better as space gets tight. Keep iron and calcium (~1000 mg/day) in view.
What Fawna does
Fawna sets your daily target to your trimester automatically, so you’re never guessing whether “+340” applies to you yet. It tracks the nutrients that matter at each stage — and it never asks for your weight or BMI. Trends are information, not a verdict.
FAQ
Do I need to count calories precisely in pregnancy? No. The trimester adjustments are guides, not targets to hit exactly. Eating to appetite with attention to key nutrients is the goal.
Which foods should I be careful with? Some foods carry higher risk in pregnancy (certain cheeses, undercooked meat, high-mercury fish, unpasteurised products). Follow your local health service’s list and ask your midwife or doctor.
References
- RCOG — Healthy eating and vitamin supplements in pregnancy (2022)
- Institute of Medicine — Dietary Reference Intakes: Energy (2005)
- NICE NG247 — Maternal and child nutrition (2025)
General information, not medical advice. Reviewed for accuracy; always consult a qualified professional about your health.
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