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Why Do We Eat?

Why we continue to eat when we are no longer hungry.

The answer to the question “Why do we eat?” seems an obvious one—to obtain the energy we need to support our everyday activities and, ultimately, promote our survival. However, many of our modern day food choices suggest another answer—one that actually stands to threaten our health and well being.

Many times, the reason we eat has less to do with sustenance and more to do with taste. Moreover, our daily food choices are influenced by a variety of other factors including the social situations we find ourselves in, our budgets, sleep schedules, and stress levels, as well as the amount of time we have to prepare and eat a meal.

A quick comparison between the food landscape of our ancestors and the current environment shows dramatic changes on both sides of the energy balance equation (energy expended vs. energy consumed). In more primitive times, hunters and gatherers foraged for vegetation and hunted animals to eat. They worked hard and expended energy to obtain foods that were not typically calorically dense. As a result, their energy expenditure was more closely balanced with their energy intake.

Advances in agriculture and modern farming techniques have provided the opportunity to grow massive quantities of food with far less effort than before. On the other side of the equation, there has also been a dramatic change in our food sources. Today, many food items are highly processed combinations of several palatable ingredients and chemicals. The food industry creates and markets food and beverage products that are engineered to be both desirable and inexpensive. For instance, foods such as corn and wheat are transformed from their original form and combined with salt, fat, sugars, and other ingredients to produce the low cost, high energy food and beverage items that line our grocery store shelves.

Even though food is essential for survival, not all foods are created equal. Eating certain foods, especially in excess, can produce the opposite effect of sustaining life by compromising our health. Overeating and obesity are on the rise in both the United States and around the world.

Despite warnings of the physical health risks associated with increased body weight, the plethora of diet books and programs available, and the stigma associated with excess weight, many people find it difficult to achieve and maintain a healthy body weight. Thus, it is important to consider what other factors are driving weight gain or sabotaging weight loss efforts. It is impossible to avoid the fact that the pleasurable aspects of foods are powerful motivators of our choices.

The basic biology underlying food intake is closely linked to pleasure. Since food is necessary for survival, eating, especially when hungry, is inherently reinforcing. However, eating can be reinforcing even when it is not driven by a caloric deficit. This is why we continue to eat past the point of satiation and eat highly palatable foods like cupcakes and candy bars that aren’t filling. Unfortunately, our natural inclination to consume these types of foods collides with the many influences in our modern food environment—such as convenience, cost, and social influences—to ultimately encourage the overconsumption of highly palatable foods.

In my new book, Hedonic Eating, I examine the various behavioral, biological, and social factors associated with highly palatable food consumption in an effort to offer greater insight into what promotes this behavior and shed light on the different factors that may be involved in perpetuating current obesity epidemic.

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