Weaning your baby and food allergies

Weaning your baby onto solid food is exciting but can also be daunting. Worrying about food allergy is a real concern for most parents when you start weaning your baby. How will you know if your baby is going to be allergic to a food? Could they have a life threatening reaction? Its scary stuff!

However, the vast majority of babies will be absolutely fine. Food allergy – although well known about – is extremely rare. Having said that a child is more likely to develop an allergy (during weaning or at anytime during their life) if they have a parent or sibling who has an allergic condition whether that be asthma, eczema, hay-fever or a food allergy.

There is medical evidence that suggests breastfeeding exclusively for the first 4-6 months (which means no bottles of infant formula at all) has a protective effect against your baby developing an allergy. Avoiding eating certain foods while breastfeeding won’t make a difference, so there’s no need to restrict your diet.

So what should you do?

For babies who don’t have parents or siblings with allergies, eczema or hay-fever

Start introducing solid food to your baby in the normal way. You should be starting at around 6 months when your baby is developmentally ready click here for a FREE download on three tests you can do to check if your baby is ready.  There’s no need to introduce foods singly, mix things up a bit you can create some wonderful flavour combinations. Nutrition is critical at this stage in your baby’s development so avoid sticking to just fruit and vegetables for weeks on end. They need protein, energy dense foods and lots of iron. Click here for more information on the critical nutrients for babies and the best weaning foods.

For babies who have severe eczema or have a parent or sibling with asthma, eczema, allergy or hay-fever

Start when your baby is developmentally ready which is usually around 6 months (26 weeks). You can feed them all the usual fruit and vegetable foods at the start of weaning and don’t forget the importance of other foods in order for them to be properly nourished with those critical nutrients.

The up to date advice is to continue weaning your baby in the usual way, giving the allergenic foods alongside a normal weaning diet, but it makes sense to keep a food diary and note any unusual signs and symptoms when offering new foods.

The advice is to introduce the other allergenic foods, one at a time between 4 months and 12 months of age. Delaying introduction of these foods beyond 12 months can actually make the likelihood of having an allergy greater.

It is advisable to start with egg and then peanut, after that the other allergens detailed on the list below can be offered. 


Choose british red lion stamped eggs and offer both the white and the yolk together. Something like scrambled egg or omelette strips work well.


You mustn’t give your baby whole nuts due to the risk of choking, and peanut butter on a spoon can also pose the same risk. Puffed peanut snacks, peanut powder mixed into food or a small amount of smooth peanut butter warmed and thinned down with some of your baby’s usual milk or hot water are better options. You can add this thinned peanut butter to pureed fruits or vegetables. 

If your baby tolerates these foods without a reaction, continue offering them regularly as part of their normal diet. This repeated exposure has a protective effect.


You can then start to offer the other common allergenic foods alongside other tolerated foods. Just offer one at a time (no more frequently than one new food per day) and just ¼ to ½ teaspoons worth, so that if your baby does react you know which one was the culprit.

  • Tree-nuts - almond, cashew, walnuts, brazil nuts, pecans, hazelnuts etc prepared in the same way as peanuts above.

  • Wheat - breakfast cereals, pasta, bread, couscous, breadsticks

  • Sesame - such as houmous which contains tahini (sesame paste)

  • Fish & seafood - cod, haddock, salmon, trout, tuna, prawns, crab, mussels

Again if your baby tolerates them continue offering them regularly as part of their normal diet to capitalise on the protective effect of repeated exposure.

If you are very worried you may want to seek advice from an allergy specialist doctor before starting, you can see your GP to arrange a referral. An allergy specialist doctor may suggest carrying out allergy testing first.

Allergies can be immediate or delayed. The symptoms you might see immediately are vomiting, hives or a red rash, swelling in the mouth or throat, wheezing, shortness of breath, and difficulty breathing.  Delayed reactions are more likely to be colic-like symptoms, eczema, vomiting, diarrhoea, constipation, a stuffy, itchy nose and poor weight gain and growth. If your baby experiences breathing difficulties this is a medical emergency so dial 999 for help.

Food allergies are managed by avoiding the food that’s caused the reaction. If this is milk, wheat, soya or egg or a combination of several foods please ask to see an NHS dietitian who specialises in children or find one privately via freelancedietitians.org. This is extremely important as getting the right balance of critical nutrients needed for growth and brain development in the first 2 years of life can be a challenge. A dietitian will also help you avoid all traces of the offending food and advise on how and when to reintroduce it safely.

Further Information

If you’ve found this post useful and want to know more about your baby’s nutrition and growth during their first year of life, I host an Online Baby Nutrition & Weaning Course. Follow the link to find out more.


Sarah Almond Bushell MPhil, BSc (Hons) RD MBDA - Registered Dietitian & Children’s Nutritionist

Sarah Almond Bushell MPhil, BSc (Hons) RD MBDA - Registered Dietitian & Children’s Nutritionist