Chewing transforms food into a mass that is safe for swallowing, and it is the first stage of digestion. With the help of saliva, food is broken down into smaller particles. This increases the surface area for amylase, a digestive enzyme, to act on. In fact, according to Richard Mattes, M.P.H., Ph.D., a food and nutrition researcher at Purdue University, much of a food’s energy and nutrients are locked away until its cell walls are broken down by chewing. Chewing also releases the flavors of food.
No. Different foods require different amounts of chewing: hard and dry foods (such as nuts and carrots) need more than soft foods; many meats and vegetables are also “chewier.” People also vary in chewing efficiency. Some slam their teeth together and so need more time to break a food down to swallowable size; others use a more efficient shearing motion. People also vary in jaw anatomy and strength, saliva flow and other factors. And some simply eat faster and swallow bigger food particles. It can take one person nine chews to swallow a piece of carrot, another 65.
Older people tend to have a weaker and less efficient bite, but adapt by working harder and/or chewing longer. If you have lost teeth or wear dentures, however, this can significantly compromise your chewing, and possibly even your nutritional status. People who have trouble chewing are less likely to eat fresh fruits, vegetables and meats, which require more vigorous chewing, and they’re also more likely to swallow larger food particles, which may not be absorbed as well as smaller ones.
When you chew food slowly, it allows satiety signals time to reach the brain (it takes about 20 minutes) and that may help you eat less at one sitting. Over time, more mindful eating habits like this one can aid weight control.
Get regular dental checkups to keep your teeth healthy. If you wear dentures, make sure they fit well. If you have trouble chewing due to reduced saliva (dry mouth), try sipping a little water while you eat solid foods (especially dry foods, like crackers). If you have chronic dry mouth, talk to your doctor—it may be due to illness or a drug you are taking. You may be able to switch medications; there are also over-the-counter and prescription drugs that can help reduce dry mouth.