Introducing solid food to babies before they reach six months might offer a small improvement to their sleep, new research suggests.

Researchers from the UK and US looked at data collected as part of a clinical trial exploring whether early introduction of certain foods could reduce the chance of an infant developing an allergy to them. As part of the study the team also looked the impact on other measures, including growth and sleep.

“An added benefit (of early introduction of solids) is that it seems to confer better sleep for the children,” said Gideon Lack, professor of paediatric allergy at King’s College London, and a co-author of the research.

Writing in the journal Jama Pediatrics, Lack and a team of researchers behind the study say while there is a common belief that eating solid food helps a baby to sleep better – with one NHS survey suggesting most mothers give their child food before five months – many sources of advice for new parents, including the NHS and the National Childbirth Trust, recommend that parents should wait until six months before introducing solids.

“We believe the most likely explanation for our findings of improved sleep is that that these babies are less hungry” said Lack, adding that solid foods might mean less regurgitation or greater feelings of being full.

More than 1300 healthy breastfed three-month-olds were split randomly into two groups in one the babies were exclusively breastfed until they were six months old – as current guidelines recommend – while children in the other group were breastfed and given solid foods, including peanuts, eggs and wheat, from the age of three months, in addition to breastfeeding. After six months babies in both groups were eating a range of solids.

The children’s health and behaviour was followed for three years, with their sleep and consumption of solid food tracked by families through questionnaires.



While not all babies were kept to their allotted regime, on average, babies who were in the breastfeeding only group were first introduced to solids at around 23 weeks, while those in the other group encountered the foods at around 16 weeks

The results, based on data from 1,162 infants and taking into account factors such birth weight and whether children had eczema, reveal babies introduced to solids from three months slept, on average, two hours more a week at the age of six months, than the babies who were only breastfed. They also woke around two fewer times at night per week at six months and had just over 9% fewer incidents of waking up during the night over the course of the study.

The team found that the more closely parents stuck to the early introduction programme, the stronger the effect.

Lack said a crucial finding is that parents who were asked to exclusively breastfeed had almost twice the odds of reporting a serious problem with their child’s sleep than those who were asked to introduce their babies to solid food early.

The team did note that the study did not use sensors to monitor infants’ sleep and that parents might have misreported sleeping behaviour because they had previously encountered the idea that babies fed solid foods earlier sleep better.

However Professor Amy Brown of Swansea University, whose research includes weaning of babies, said the benefits revealed by the study were “minimal” in real-world terms, and that other research showed no rewards for early introduction of solids.



“There is no clear physiological reason why introducing solids foods early would help a baby sleep, especially not for the very small amounts parents were instructed to give in this trial,” she said.

Brown urged caution, noting that no difference in waking was seen until after five months, despite one group being introduced to solids from three months, and that self-report of infant sleep by tired parents was unlikely to be precise.

Prof Mary Fewtrell, nutrition lead for the Royal College of Paediatrics and Child Health welcomed the study, noting the RCPCH currently recommends solid foods are not introduced before four months, but that the evidence base for current advise is more than 10 years old and is currently under review in the UK and EU. “We expect to see updated recommendations on infant feeding in the not too distant future,” she said.

Erin Leichman, a senior research psychologist at St Joseph’s University, Philadelphia, and executive director of the Pediatric Sleep Council said while the impact of early introduction of solid foods likely varied across babies, the findings are important. “Results of this study certainly warrant further research on the topic, particularly addressing how long babies continue to breastfeed despite introduction of solids and how parents interact with their babies at bedtime and during the night after a night waking, which can be related to sleep and night wakings,” she said. “At this point, results of this study do not indicate that solids should be introduced early for all babies.” Making the decision about when to introduce solid foods should be one that is family-based, and made with a trusted health-care provider.”