“Be sure you chew that well.” It’s a phrase I’m sure I’ve uttered hundreds – if not thousands – of times. But it’s not something that I’ve ever really thought about. Do kids have to learn to chew or does it come naturally? Can I teach my kids how to chew more efficiently or effectively? Do the foods I feed them have any influence on their ability to chew?
While planning for the Introducing Food to Baby series, I came across a recent review article which looks at the science of mastication – or chewing. It describes the physical mechanics of chewing (what abilities develop and when), as well the behavioral aspects of feeding and food acceptance and the influence that chewing has on these. Each of these has important implications for the timing of introduction and the selection of first foods. Here’s what I’ve learned.
Form and Structure
There are four major components of the “mastication apparatus” including bones, muscles, teeth and soft tissue (tongue, lips and cheeks), all of which play very important roles in a person’s ability to chew.
Not surprisingly, these components are not static over the course of a child’s development. Bone dimensions, for example, change as much in the first year of life as they do between age one and puberty! The number of teeth increases as children grow, providing greater stabilization of the jaw, and the tongue and lips change from undifferentiated to refined movements, which help improve chewing effectiveness.
Learning to Chew
Researchers have used a variety of methods and measures to understand when and how children become efficient chewers and these findings have important implications for informing the type (texture and consistency) and size of food particles that are idea to offer children during the introduction of solid foods. Let’s review a few:
- By 6 and 8 months children have reached maturity for handling pureed and semi-solid foods, respectively. The ability to fully handle solid textures, however, continues to increase through 24 months, suggesting that harder, cereal-like textures continue to promote healthy chewing abilities at that age (in other words, at 24 months kids still haven’t fully developed their ability to chew harder textures and practice helps them to do so).
- Between 4-6 months of age, the tongue mashes food in an upward/downward motion which is less efficient. Around 10 months of age, the tongue begins moving food from side-to-side within the mouth and becomes large enough to create a central grove. These are necessary developments for proper chewing and swallowing.
- Between 4 and 6 months of age, jaw movements are simple elevations, rather than rotational movements, which are the hallmark of mature mastication. Several studies reported that these rotary movements don’t appear until 24-30 months of age, but food form seems to play an important role: at least one study reported that fully mature jaw movements were not observed in children as old as 11 years unless they were eating hard jelly.
Taken together, this body of research suggests that although toddlers are still learning to fully master chewing, the development of mature mastication depends on the introduction and frequent interaction with foods of differing textures over the course of their early exposure to solid food.
Can Food Texture Impact a Child’s Future “Pickiness?”
Appropriate texture introduction also appears to increase food acceptance. While some studies have shown that babies prefer pureed textures to lumpy or diced ones, they became increasingly interested in complex textures as the number of teeth increased. Early exposure (before 10 months) to solid foods has also been associated with a reduction in “picky eating,” the effects lasting anywhere from 15 months to 7 years of age. Similar findings have been reported for exposure to a variety of tastes and flavors, suggesting that this early exposure during complimentary feeding may ultimately help your child become a more adventurous, and more accepting eater.
Putting It All Together
So what does this mean for you? There are several key take-away messages from this review article which are pertinent as you think about introducing foods to your child.
- Don’t be afraid. As long as the foods you’re putting in front of your kids aren’t choking hazards, pieces of food are okay for your 7 month old. Purees and semi-solids are okay too, but they aren’t for every child (my second refused these textures entirely), and they should not be the only experience with solid food that your infant has. Help them safely explore food.
- Practice makes perfect. Abilities develop over time. More teeth, a larger mouth, stronger muscles: these will all help make eating easier. And many of these aspects will develop more fully if your child has a chance to use them. So give your kids a lot of opportunity to practice and develop their chewing, swallowing, and feeding skills.
- Try, try, and try again. Children’s taste preferences and their abilities to handle different textures are constantly evolving so give them an opportunity experience a particular aspect of food – lumpy texture, new flavor – then give it to them again and again. Acceptance comes through repeated exposure (and practice. Have we said practice?)
- Choose a variety. Although it usually recommended that parents give their infants entirely pureed foods, providing a variety of textures, consistencies, forms, and sizes (safely, of course!) will benefit them.