Babies Weaned Onto Solid Foods Sooner Sleep Longer and Wake Less Often, Study Suggests

Babies who are weaned onto solid foods sooner sleep longer and wake less, a study has suggested.

Researchers wanted to understand whether a baby's diet could affect their sleeping pattern. They found children who progressed to solid foods had fewer issues with sleep than babies who were only breastfed for the first six months of their lives.

The findings contradict current recommendations by the Center for Disease Control and Prevention, which advises parents to move babies on to solid food at 6 months old.

In the randomized clinical trial, the parents of around 1,300 3-month-old babies from England and Wales were either asked to follow standard feeding advice and to breastfeed for around 6 months or introduce solid foods to their baby's diet from the age of 3 months.

The parents completed online questionnaires monthly until their baby was 12 months old, and then every three months until the babies were 3 years old. Questions included how often the babies were fed, how often and how long they were breastfed and how much they slept. Mothers also reported on their individual physical and psychological health, as well as social relationships and their environment.

The results suggested infants who moved on to solids earlier slept longer and woke less often than those who were breastfed until 6 months of age.

The difference between the two groups was most stark six months into the test, the researchers found. The infants who ate solids sooner slept for 16.6 minutes longer per night than those who were exclusively breastfed—almost two hours a week on average. At night, the amount they woke up dropped from twice to 1.74 times on average.

Mothers appeared to benefit, too, as sleep problems defined by the parents were reported less frequently in the solids group.

Dr. Michael Perkin, co-lead author of the study and senior lecturer in clinical epidemiology St. George's, University of London, told Newsweek: "We show for the first time in a randomized clinical trial setting that, consistent with the belief of many parents, the early introduction of solids does have a small but significant effect on sleep characteristics."

The take-home message for parents was "an infant introduced to solids before 6 months may experience a small but significant improvement in sleep characteristics," said Perkin.

However, the doctor stressed parents should not try to rush their child into eating solids. "Parents should introduce solids at the pace their infant is comfortable with," he said.

Mary Fewtrell, a professor and a nutrition lead at the U.K.-based Royal College of Pediatrics and Child Health (RCPCH) who was not involved in the study, commented: "These are interesting findings from a large randomized controlled trial. At the RCPCH, we recommend that mothers should be supported to breastfeed their healthy term infant exclusively for up to six months, with solid foods not introduced before four months."

However, she said the evidence used for existing advisory on breastfeeding is over 10 years old, and is being reviewed by scientific bodies in the U.K. and the E.U.

"We expect to see updated recommendations on infant feeding in the not too distant future," she said.

Dr. Clare Llewellyn, a lecturer in behavioral science and health at the U.K.-based University College London, who did not work on the research, told Newsweek that because mothers reported how long their babies slept, "we can't be certain if the mothers who introduced solids earlier were biased by the commonly held view that infants who are given solids earlier sleep for longer.

"However, the longer sleep duration of the infants was evident well beyond 6 months of age [when all the infants were eating solids], so this seems unlikely," said Llewellyn, the author of infant nutrition book Baby Food Matters.

"This is the first study of its kind, and far more research is needed to establish the link between timing of introduction to solid foods and sleep," she said. Llewellyn warned introducing solids before 17 weeks has been linked with an increased risk of obesity and other problems.

"Breast milk boosts an infant's immune system and contributes to brain development, so there are also benefits to exclusive breastfeeding for six months," she explained. "The well-established benefits of breast milk need to be weighed up against the potential benefits of early introduction of solid food which displaces breast milk."