NUTRITION AND APPETITE

The chemical senses are the gatekeepers of the body. They provide information about substances in the outside world and thus influence our decisions of what to eat and drink. Our responses to many flavors appear to be hard-wired, but they can also be modified by experience. Much of what we like and dislike about flavors is learned.

Scientists at Monell explore factors related to food choice and intake across the human lifespan. The Center’s research program with human infants examines the role of early experience on development of flavor preferences later in life. The late-term fetus has functional chemosensory systems that can detect tastes and odors, and research at Monell has shown that flavors associated with the mother’s diet are passed into the amniotic fluid. Such transmission of flavor may provide the fetus with an early introduction to elements of the mother’s cuisine. Following birth, flavors from foods and beverages, including alcohol, ingested by the mother pass into breast milk, and can influence feeding and other behaviors of the breast-fed infant.

At the other end of the lifespan, research at the Center has shown that loss of olfactory sensitivity in the elderly affects food perception by these individuals. Current studies at Monell are exploring food preferences and nutritional status of the elderly population. Changes of chemosensory function can profoundly influence food choice and nutritional status of this rapidly-growing segment of the population. For example, olfactory loss can diminish food cravings and also aversions.

Other studies at Monell are examining how flavor activates hormonal and neural responses that affect how we digest and utilize nutrients. In related experiments, scientists are learning how changes in the body’s metabolism can influence how we respond to the flavor of food.

Many ongoing areas of study at Monell are related to nutrition and appetite. These include studies intended to advance the understanding of:

• How chemosensory changes affect food preferences and nutritional status in elderly humans
• Physiologic and learned controls of calcium and sodium intake
• Influence of early flavor experiences on development of food preferences and behavior in infants and children
• How abnormal hormonal and neural responses, initiated during food ingestion by chemosensory receptors in the mouth and nose, contribute to impairment of blood glucose control in obesity and diabetes.
• How alterations in nutritional status affect the ability of the olfactory epithelium to regenerate after injury
• How changes in the body’s energy status are sensed by the liver and relayed to the brain to influence eating behavior
• Genetic determinants of preferences for sweet taste, bitter taste, and for alcohol
• The effect of diet palatability on food intake and body weight gain
• The contributions of calories, individual macronutrients, artificial sweeteners, and fat replacers to food choice and satiety
• The roles of the chemical senses and nutritional need in triggering food cravings
• Chemosensory influences on willingness to try novel foods