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How to help your baby gain weight

If your baby is gaining slowly, small, consistent changes to feeding — and a clear record of the trend — usually help more than worry. Here is what tends to work, and when to get help.

Updated 9 June 2026 · VitaBaby

In short

To help your baby gain weight, focus first on feeding effectively and often — frequent, unhurried breast or bottle feeds, a good latch or paced bottle-feeding, and offering extra feeds rather than longer gaps. Once your baby is weaning at around six months, add energy- and nutrient-dense foods such as full-fat dairy, avocado, and healthy oils alongside iron-rich foods, while keeping milk feeds up. Track the weight trend on the centile chart, and always review persistent slow gain with your health visitor or GP, who can rule out an underlying cause.

Written for UK parents and aligned with current NHS and NICE guidance. Last updated 9 June 2026.

Key takeaways

  • Effective, frequent feeding matters most in the early months — latch, paced bottle-feeding, and offering extra feeds.
  • From around six months, add energy- and nutrient-dense first foods rather than relying on volume alone.
  • Track the trend on the centile chart so you can see whether changes are working.
  • Persistent slow gain should always be assessed by a health visitor or GP to rule out an underlying cause.

Start with feeding, not food

In the first six months, milk — breast or formula — provides almost all of your baby’s energy, so the biggest lever for weight gain is feeding effectively. That means frequent, unhurried feeds, a comfortable latch when breastfeeding, and paced bottle-feeding so your baby takes a full feed rather than rushing or tiring. Offering an extra feed, or feeding a little more often, usually helps more than trying to force larger volumes.

If breastfeeding feels difficult or your baby tires quickly, ask your health visitor or an infant feeding specialist to check positioning and latch. A small change there can make a noticeable difference to how much milk your baby takes.

Add calories once weaning

From around six months, solid foods become a chance to add energy and nutrients on top of milk. For a slow-gaining baby, aim for calorie- and nutrient-dense first foods rather than large portions, and keep milk feeds going alongside solids through the first year.

  • Full-fat dairy — yoghurt and cheese, and milk used in cooking (not as a main drink under one year).
  • Avocado, olive or rapeseed oil, and smooth nut butters thinned into food.
  • Iron-rich foods from around six months: well-cooked egg, beans and lentils, soft meat or fish.
  • Offer food after or between milk feeds so milk intake stays up.

Keep watching the trend

Weigh consistently and plot each reading on the WHO/Red Book centile chart so you can see whether your changes are helping. Look for your baby settling back onto their own line over several weeks, rather than expecting a jump on any single weigh-in. Daily weighing tends to add worry without adding information.

When to see your health visitor or GP

Speak to your health visitor or GP if your baby is gaining slowly despite feeding well, has crossed downward through centile lines, feeds poorly or tires quickly, or you are simply worried. Slow gain sometimes has an underlying cause — such as reflux, cow’s milk protein allergy, or a feeding difficulty — that is worth identifying. Our guides on faltering growth, reflux and slow weight gain, combination feeding, and calorie-dense recipes cover each of these in more detail.

VitaBaby helps by logging every feed and meal, totalling daily calories and nutrients, and charting the weight trend — so you can see whether your changes are working and bring a clear picture to your appointment.

FAQ

What foods help a baby gain weight?

Once weaning, energy- and nutrient-dense foods help most: full-fat dairy, avocado, healthy oils, smooth nut butters thinned into food, and iron-rich foods like egg, lentils, and soft meat. Under six months, effective and frequent milk feeds matter more than any food.

My baby is gaining slowly but seems happy — should I worry?

A baby who is alert, feeding, and following their own centile line is often doing well even if gain is slow. Persistent slowing, downward centile crossing, or poor feeding are the patterns to review with your health visitor or GP.

Can I give my baby extra formula to help weight gain?

Never add extra formula powder to make feeds stronger — always make up formula exactly to the instructions, as over-concentrated feeds are unsafe. If you think your baby needs more milk, offer more frequent or additional feeds and speak to your health visitor.

Sources

Related guides

This guide is general information, not medical advice. For concerns about your baby’s growth or feeding, speak to your health visitor or GP.