What to Eat in the First Trimester

The first trimester (weeks 1-12) is when your baby's organs are forming, making nutrition especially important. But with morning sickness, food aversions, and exhaustion to contend with, eating well can be a challenge. Here's how to nourish yourself and your baby in those crucial early weeks.

Table of Contents

1. Why the First Trimester Matters
2. Key Nutrients for the First Trimester
3. Foods to Focus On
4. Foods to Avoid
5. Managing Morning Sickness Through Diet
6. When Eating Is Hard
7. Sample First Trimester Day

Why the First Trimester Matters

Your baby is growing rapidly, even though they're still tiny. By 12 weeks, your baby is about 5-6cm long with a beating heart, forming limbs, and developing organs. All of this requires nutrients from you.

However, you don't need extra calories in the first trimester. Your baby is small enough that your normal calorie intake (around 2,000 per day) is sufficient. Focus on the quality of your food, not the quantity.

Key Nutrients for the First Trimester

Iron

• Why: Your blood volume increases in pregnancy; iron makes haemoglobin to carry oxygen
• How much: 14.8mg per day
• Food sources: Lean red meat, dark leafy greens, beans, fortified cereals, dried apricots
• Tip: Eat iron-rich foods with vitamin C (like orange juice) to boost absorption. Avoid tea and coffee with iron-rich meals (they reduce absorption)

Vitamin D

• Why: Helps absorb calcium for your baby's bones; supports your immune system
• How much: 10mcg daily supplement throughout pregnancy
• Food sources: Oily fish, eggs, fortified foods. (Sunlight is the main source, but UK levels are often low)
• Tip: Take it with a meal containing fat for best absorption

Calcium

• Why: Your baby's bones and teeth are developing
• How much: 700mg per day
• Food sources: Milk, yoghurt, hard cheese, fortified plant milks, leafy greens, tofu, sardines

Omega-3

• Why: Supports brain and eye development
• Food sources: Salmon, mackerel, sardines, walnuts, chia seeds, flaxseeds
• Tip: Eat 2 portions of fish per week, including 1 oily fish

Vitamin B6

• Why: May help reduce nausea; supports brain development
• Food sources: Poultry, fish, potatoes, bananas, nuts, seeds

Foods to Focus On

• Leafy green vegetables: Spinach, kale, broccoli — packed with folate, iron, and calcium
• Fortified cereals: Many breakfast cereals are fortified with folic acid and iron — an easy win
• Lean protein: Chicken, turkey, eggs, beans, lentils, tofu
• Oily fish: Salmon, mackerel, sardines (limit to 2 portions per week)
• Dairy (pasteurised): Milk, yoghurt, hard cheese — for calcium and protein
• Wholegrains: Brown rice, wholewheat bread, oats — for fibre and B vitamins
• Colourful fruit and vegetables: Berries, citrus, peppers, carrots — for vitamins and antioxidants
• Nuts and seeds: Walnuts, almonds, chia seeds, flaxseeds — for healthy fats and minerals

Foods to Avoid

• Soft mould-ripened and blue cheeses
• Raw or undercooked meat and fish
• Liver and liver products (too much vitamin A)
• Raw eggs (unless British Lion Code stamped)
• Unpasteurised milk and dairy
• Shark, swordfish, and marlin
• Limit caffeine to 200mg/day
• Avoid alcohol completely

See our complete foods to avoid guide for the full list.

Managing Morning Sickness Through Diet

• Eat little and often: Small, frequent meals prevent an empty stomach, which worsens nausea
• Bland, plain foods: Crackers, toast, rice, plain biscuits — easy to keep down
• Ginger: Ginger tea, ginger biscuits, or ginger capsules can reduce nausea (don't exceed 1g per day)
• Cold foods: Often easier than hot foods because they have less smell
• Stay hydrated: Sip water throughout the day. Try ice lollies if you can't face drinks
• Avoid triggers: Strong smells, spicy foods, fatty foods. Everyone's triggers are different
• Eat before getting up: Keep crackers by your bed and eat a few before standing

See our full morning sickness foods guide for more tips.

When Eating Is Hard

• Prioritise hydration: Water is more important than food. Sip constantly.
• Eat whatever you can keep down: If only crackers and ginger ale work, that's fine for now.
• Take your folic acid: Even if you can't eat, try to take your supplement. If you can't keep it down, ask your GP about alternatives.
• Talk to your GP: If you can't keep any food or water down, you may need anti-sickness medication or IV fluids. Don't suffer in silence.
• Don't worry about nutrition short-term: Your baby will take what they need from your stores. A few weeks of poor eating won't harm them — getting through the sickness is the priority.

Sample First Trimester Day

• Breakfast: Bowl of fortified cereal with milk and a handful of berries + folic acid supplement
• Mid-morning snack: A banana and a handful of almonds
• Lunch: Chicken and salad sandwich on wholegrain bread, with a glass of orange juice (for vitamin C with iron)
• Afternoon snack: A yoghurt and a few crackers (if nausea strikes, just the crackers)
• Dinner: Grilled salmon with brown rice and steamed broccoli + vitamin D supplement
• Evening: Ginger tea and a piece of fruit

If morning sickness hits, swap to: crackers, toast, plain rice, soup, and cold foods throughout the day.

Frequently Asked Questions

No. You don't need extra calories in the first 12 weeks. Your baby is small enough that your normal intake is sufficient. Extra calories are needed from the second trimester onwards.

What if I can't eat vegetables due to food aversions?

Don't worry. Food aversions are common and temporary. Focus on what you can eat, and try hiding veg in soups or smoothies. Your prenatal vitamins will help fill the gaps. Most aversions ease by the second trimester.

Should I take folic acid even if I eat lots of folate-rich foods?

Yes. The NHS recommends a 400mcg folic acid supplement regardless of your diet, because it's hard to get enough from food alone, and the synthetic form is more easily absorbed. Continue until 12 weeks.

This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider.

Last reviewed: June 2026

Related articles:

• Healthy Diet in Pregnancy
• Best Foods for Morning Sickness
• Pregnancy Meal Plan: First Trimester
• Foods High in Folic Acid