Are Brain and Taste 'Branded' for Food?

Most of us have heard that the prevalence of childhood obesity has increased dramatically. The rate has tripled in the past 30 years. The consequences of obesity are grim for children and adults, including health problems such as Type 2 diabetes, high blood pressure, heart disease and cancer. Obesity is also associated with psychosocial difficulties like bullying, discrimination, anxiety and depression. Experts say that because of the consequences of obesity, our current generation of children will be the first in many to live shorter lives than their parents. From an economic perspective, obesity is expensive, with a cost of $147 billion each year in the United States alone.

What causes obesity? At the most basic level, obesity results from a chronic imbalance such that energy intake is greater than energy expenditure. But the reasons for this seemingly simple equation, that calories consumed are greater than calories burned, are quite complicated. The reasons for a chronic energy imbalance range from brain activation differences to genetic predispositions, from the sense of taste to societal influences.

Food marketing is one factor believed to contribute to the increasing obesity epidemic. Each year, companies spend $10 billion advertising their products to children. And an overwhelming majority, 98 percent, of the food products advertised to children on television are high in fat, sugar or sodium.

Many factors affect eating habits, but one of the most important is taste. Individuals who have lost their sense of taste are no longer motivated to eat. On the other hand, researchers have shown that consumption of sweet-tasting foods can activate the same parts of the brain that are involved in drug addiction, leading to the idea that people may actually develop "food addictions." Overconsumption of sugar and carbohydrate-rich foods during childhood may lead to lasting changes in these brain "reward" systems, and contribute to the development of lifelong poor dietary habits.

In recent years, researchers have used brain imaging to gain a better understanding of food motivation and how the brain is involved in eating behaviors and obesity. Studies show that brain activation patterns in obese and healthy-weight individuals differ in response to food. We are only beginning to understand whether this is a cause or effect, however. Early evidence suggests that after healthy weight loss, a person's brain activation patterns change.

Children are bombarded with advertisements every day, yet little research has investigated how this affects children at the neural level. Using neuroimaging, we can study the effects of food logos on obese and healthy-weight children. A recent study showed children's brains "light up" in response to familiar logos. But healthy-weight children showed greater brain activation in regions of the brain associated with self-control, when shown food versus nonfood logos. In addition, the group of healthy-weight children said they had more self-control than the obese children.

These findings add to the body of research showing that in certain situations, healthy-weight individuals experience greater activation of control regions of the brain than obese individuals. It is possible obese children may be more vulnerable to the effects of food advertising. This raises questions about the ethics of advertising unhealthy foods to children, particularly children who are overweight or obese.

Amanda Bruce is a clinical psychologist and researcher at the University of Missouri-Kansas City. John Boughter is a neuroscientist at the University of Tennessee Health Science Center. They will speak at a public symposium on eating behaviors and the brain, called "Train Your Brain: How Early Eating Habits Affect Brain Development and Childhood Obesity," from 6:30 p.m. to 8:30 p.m. on March 21 at The Urban Child Institute, 600 Jefferson Ave. Bruce will discuss the relationship between food marketing, the brain and childhood obesity; Boughter will talk about taste and the brain.

This article was originally published online by The Commercial Appeal: