Why it's worth waiting until 26 weeks to introduce solids

Let’s talk about solids, 26 weeks, and all the noise in between.

You’ve got your mam, your auntie, Instagram, the PHN and maybe the random woman in Tesco all giving you different advice. “Sure I had you on baby rice at 10 weeks and you’re grand.” Sound familiar?

So why are so many professionals now saying “wait until about 6 months / 26 weeks” before introducing solids?

This isn’t about scaring you or judging what you’ve already done. It’s about giving you clear, evidence-based info so you can make decisions that sit well in your own gut… while your baby’s gut is still maturing nicely.

What do the big organisations actually say?

Here’s the gist from the people who spend their lives buried in the research:

• The World Health Organization (WHO) recommends exclusive breastfeeding for the first 6 months, and then adding in complementary foods (solids) at 6 months while continuing to breastfeed.

• The HSE in Ireland says to start solids “around 6 months” when baby shows signs of being ready, whether breastfed or formula-fed. H

• The NHS in the UK also advises waiting until around 6 months, to give babies time to develop so they can cope properly with solid foods.

• European experts (ESPGHAN) say breastfeeding for about 6 months is the goal and that solids shouldn’t start before 4 months; for most babies, somewhere between 4–6 months is the “window”, but 6 months is still seen as the ideal overall.

So where does “26 weeks” come from? It’s basically the practical version of “6 months” – not “5 months and a bit because I’m bored of bottles / boobs now”, but a clear point in time when baby is truly around that 6-month mark.

Why wait? What’s actually happening in your baby’s body?

1. Their gut is still under construction

For the first months, your baby’s digestive system is like a building site: brilliant, busy, but not fully finished. Human milk (and to a lesser extent, formula) is designed to be the main fuel in this phase.

Waiting until around 6 months gives:

• More time for the gut lining to mature

• More time for the immune system in the gut to develop

• More time for the microbiome (the community of bacteria in the gut) to settle into a good pattern, especially in breastfed babies

Does that mean a spoon of carrot at 5.5 months will ruin everything? No. But chucking in lots of solids very early, before the system is ready, probably isn’t doing them any favours.

2. Solids are a skill – they need the muscles for it

Eating is not just about stuffing food in their mouth and hoping for the best. It’s actually a complex motor skill.

Babies are usually ready for solids when they:

• Can sit up with good head and neck control

• Have lost that strong tongue-thrust reflex (where everything gets pushed straight back out)

• Can pick up food and bring it to their mouth themselves

• Show real interest in food (watching you eat, grabbing at your plate)

These skills generally come together around 6 months.

If we start too early, we’re asking their body to do something it’s not quite built for yet. That’s when you see a lot of spitting out, gagging, or food mostly ending up on their chin rather than in their tummy.

3. Iron needs rise around 6 months – and that’s when food really helps

In late pregnancy, babies build up iron stores from their mother. After birth, they keep topping up with milk. But those stores start to run low somewhere around the 6-month mark. That’s one of the big reasons solids exist at all: to support iron and other nutrient needs as babies grow.

Iron-rich foods (like meat, lentils, beans, fortified cereals, eggs) become really useful around this time. Before about 4 months, they’re not needed; between 4–6 months, it depends on the baby, but worldwide guidance still leans towards “around 6 months”.

So waiting until about 26 weeks usually lines up beautifully with when solids are:

• Actually needed

• Actually helpful

• Actually manageable for baby

4. Long-term health: what do we know?

Research is still evolving (and scientists love to argue with each other), but some trends are emerging:

• Starting solids before 4 months has been linked in some studies to a higher risk of obesity later on, especially if babies are formula-fed.

• For allergies, it looks like there might be a “sweet spot” – not super late, not super early. Many guidelines now support introducing common allergens (like egg and peanut) around the time you start solids, instead of delaying them for years.

What we don’t have is any strong evidence that starting solids well before 6 months gives long-term benefits. We do have some evidence that very early weaning can have downsides. So again, “around 6 months” looks like a safe middle ground.

5. Protecting breastfeeding (if that’s part of your plan)

If you’re breastfeeding and you’d like to keep going, waiting until about 6 months helps:

• Your baby’s main nutrition still comes from breastmilk, which protects against infections and supports development

• You’re less likely to accidentally swap “milk feeds” for “empty-ish calories” (like occasional yoghurt drops, rice crackers and so on) too early

• Your supply has time to establish and stabilise before feeds start to gently drop away

That doesn’t mean you’ve “messed up” if you started earlier. But if you’re still on the fence, this is another reason many breastfeeding parents choose to wait until closer to 26 weeks.

So… why 26 weeks specifically?

“6 months” is a bit vague. Is that 5 months and 2 weeks? Is it at the 6-month birthday on the dot? Is it when the random app says they’re “24 weeks”?

Using 26 weeks:

• Gives a clear, easy-to-measure marker

• Makes sure baby is actually around 6 months, not still in the 5-month zone

• Lines up with how a lot of the research defines “6 months” (180 days)

Of course, babies don’t read the guidelines. Some might be flying developmentally a week early, some a couple of weeks later. “As close as possible to 26 weeks” means we’re aiming for that window, but keeping your actual baby – not the calendar – at the centre.

Signs your baby is ready for solids

Regardless of what the calendar says, look for:

• Sitting with good head control (they don’t have to sit perfectly unsupported, but they shouldn’t be flopping over)

• Able to move food from the front of their mouth to the back and swallow

• Reaching for your food and bringing things purposefully to their mouth

• Opening their mouth when food is offered, in a steady, interested way

What does NOT count as readiness:

• Waking at night (sorry, I know)

• Chewing their hands – this is a normal developmental thing

• Watching you eat – babies watch everything you do, you’re incredibly interesting

But what if we already started earlier?

First of all: no guilt. You made the best decision you could with the information, pressure and tiredness you had at the time.

If you started a bit early (say 4.5–5.5 months):

• Keep solids small, relaxed and responsive

• Make sure milk (breast or formula) is still the main nutrition

• Focus on iron-rich, nutrient-dense foods when you do offer solids

• Watch your baby – if they’re struggling to manage the food, gagging a lot, or seem overwhelmed, it’s absolutely fine to pause and try again a bit later

If you started very early (before 4 months), or your baby has allergies, growth concerns or medical conditions, it’s worth chatting with your PHN, GP, paediatrician or an IBCLC / dietitian to get personalised guidance.

When it might be reasonable not to wait right up to 26 weeks

There are some situations where a health professional might suggest introducing solids a little earlier (but not before 17 weeks / 4 months), for example:

• Certain growth or medical concerns

• Specific feeding issues needing tailored plans

• Very individual allergy strategies in high-risk families

That kind of decision should come from someone who knows your baby and your situation, not from a TikTok video.

The heart of it

At the end of the day, the reason many of us gently recommend “waiting until around 26 weeks” is simple:

• Milk is enough for the first months

• The gut, immune system and motor skills are better prepared around 6 months

• Solids are more beneficial – and more fun – when baby is truly ready

• There’s no strong evidence that rushing helps, and some hints it may not

You don’t have to get it perfect. You won’t. None of us do.

But if you’re pregnant now, or your baby is still little and you’re wondering when to start, aiming for “as close as possible to 26 weeks, when my baby shows me they’re ready” is a solid, evidence-backed, baby-centred plan.

And if anyone says “sure we did it earlier and you’re grand”, you can smile sweetly and think:

“Yes, and now I have more up-to-date information. Lucky me.” 💛

Parent Friendly Sources for further info:

• World Health Organization (WHO). Infant and Young Child Feeding: Model Chapter for Textbooks for Medical Students and Allied Health Professionals. Geneva: WHO; 2009.

• World Health Organization (WHO). Global Strategy for Infant and Young Child Feeding. Geneva: WHO; 2003.

• Health Service Executive (HSE). Starting to spoon feed your baby. Dublin: HSE; updated 2023. www2.hse.ie

• Health Service Executive (HSE). Breastfeeding and Weaning: Information for Parents. Dublin: HSE; 2022.

• National Health Service (NHS). When to wean your baby. London: NHS; updated 2023. www.nhs.uk

• European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition. Fewtrell M, et al. Complementary Feeding: A Position Paper by the ESPGHAN Committee on Nutrition. Journal of Pediatric Gastroenterology and Nutrition. 2017;64(1):119-132.

• Scientific Advisory Committee on Nutrition (SACN). Feeding in the First Year of Life. London: Public Health England; 2018.

• Irish Nutrition and Dietetic Institute (INDI). Introducing Solids to Your Baby. Dublin: INDI; 2023.

• Agostoni C, et al. Complementary Feeding: A Commentary by the ESPGHAN Committee on Nutrition. Journal of Pediatric Gastroenterology and Nutrition. 2008;46(1):99-110.

• Fewtrell MS, Bronsky J, Campoy C, et al. Complementary Feeding: A Position Paper by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition. JPGN. 2017;64(1):119-132.

• EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA). Appropriateness of the 6-month Exclusive Breastfeeding Duration for the European Population. EFSA Journal. 2024;22(3):e08345.

• Irish Department of Health. National Breastfeeding Action Plan 2023–2028. Dublin: DoH; 2023.

• Perkin MR, et al. Randomized Trial of Introduction of Allergenic Foods in Breast-Fed Infants. New England Journal of Medicine. 2016;374:1733-1743.

• Venter C, et al. Timing of Introduction of Complementary Foods in Infancy: A Systematic Review. Allergy. 2020;75(6):1356-1381.

• Horta BL, Victora CG. Short-Term Effects of Breastfeeding: A Systematic Review on the Benefits of Breastfeeding in the First Year of Life. WHO; 2013.