The advice on when to first feed a baby solid food seems to go back and forth every few years. Now, a new study claims that feeding an infant solid foods early may improve their sleep.

The authors say that solids improve the sleep because the infants are not hungry and therefore do not wake, or wake as much, compared to those who are exclusively breastfed.

About 1,300 infants were put into two groups as part of the study. One group was exclusively breastfed for about six months; the second group was breastfed but introduced to solids in their diets at about three months.

Parents reported that babies who had solids slept for about 15 minutes longer per night and had lower incidences of night waking from just over twice per night to 1.74 times per night. The peak of differences happened around six months.

Gideon Lack, a co-author and professor of pediatric allergy at King’s College London said solids may have the added benefit of improving sleep. The authors say that about 75 percent of British mothers introduce solids before five months, and 26 percent say it’s an effort to reduce night waking.

When to start solids

In the United States, the American Academy of Pediatrics recommends breastfeeding for six months and starting solids around that time. The American Academy of Allergy, Asthma, and Immunology state that infants can handle solids beginning at four months.

“I am a firm believer that solid foods should be introduced when infants are developmentally ready, which occurs sometime between four and six months for the vast majority of infants,” noted Dr. Frank R. Greer, an infant nutrition researcher at the University of Wisconsin.

Greer said the only infants who should not be introduced to solid food until after six months are those few who are not developmentally ready.

He said there is no evidence that thickening bottles improves sleep, so he doesn’t recommend it.

Greer said the large number of infants involved in the study inclines him to believe the results, but would not comment on introducing solids before four months based on the data.

“Most infants are ready to eat solids by four to six months,” said Dr. Anthony F. Porto, a pediatric gastroenterologist at Yale-New Haven Health in Connecticut.

If solids are introduced earlier than four months, there is a risk for childhood obesity, he added.

Natalia Stasenko, a registered dietitian from New York City specializing in children’s nutrition, said she doesn’t recommend starting solids until babies can sit up straight without support, start losing the “thrust” reflex and can hold up their heads.

“Starting solids before babies are ready may lead to an increased choking risk since they are not able to sit straight and manipulate the solids in their mouth safely,” she said.

Not all babies have to start solids at six months, either, Stasenko said. Some babies are ready for solids only at seven months or so, especially those born prematurely or with developmental delays.

“All babies are different when it comes to development. The most important thing is to watch for the signs of readiness for solids,” she said.

“The study showed a self-reported increase in sleep duration of only a few minutes. For me, it’s not strong evidence enough to change the current guidelines,” she added.

Stasenko said she works regularly with parents whose infants have feeding problems. She is concerned that they may hear about the study and try to push solids in order to improve infant sleep.

“At the same time, a child-parent relationship around food is instrumental in helping kids develop a healthy relationship with food and staying attuned to their hunger and satiety,” she said.

Stasenko noted that babies go through a growth spurt at three months and may require more calories.

“But to me, it’s not necessarily a sign that they need solids,” she said. “They may need more nutrition from the sources that are developmentally and nutritionally appropriate for them: breastmilk and formula.”

She said she wished that the authors emphasized that night waking is a developmentally normal behavior in babies and not something parents need to fix.

“Interestingly, the supplementary online content of the study discusses other factors affecting infants’ sleep, such as soothing methods and sleep location, which seem to be much more effective in helping babies sleep better than the early introduction of solids,” she added.

Advice on starting solid foods

When a parent is ready to start solids, they should try smooth purees and soft finger foods, Stasenko said.

“I suggest introducing new foods in the morning, to be able to observe babies for signs of an allergic reaction,” she said. If babies appear to be hungrier than usual before they are developmentally ready for solids, it is best to increase breastmilk or formula feeds.

Porto said to add a new food every three to five days to pinpoint any reactions.

Unless recommended by a doctor, it’s not a good idea to add cereal to bottles. It’s commonly done to aid children dealing with reflux.

“The role of [feeding] solids is not purely nutrition or calories. It is also about developing eating skills,” Stasenko said. “Eating is a very complex process involving numerous muscles and all senses. Babies need to be able to fully participate in feeding in order to start developing their eating skills.”