Why do we eat?

At first pass, the answer is obvious—to obtain energy to support our everyday activities and ultimately, to promote our survival. However, many of our modern day food choices suggest another answer, one that actually stands to threaten our health and functioning. Increasingly, the reason we eat has less to do with sustenance and more to do with how certain foods and drinks taste. Moreover, our food choices are influenced by a multitude of other factors including the social situations we find ourselves in, our budgets, our sleep schedules, our stress levels, and the amount of time we have to prepare and eat a meal.

In more primitive times, hunters and gatherers foraged for vegetation and hunted animals to eat. Our ancestors expended energy to obtain foods that were typically not dense with calories, and as a result, their energy expenditure was more closely balanced with their energy consumption. A comparison between the food landscape of our ancestors and our current environment shows changes in the energy balance equation (energy expended vs. energy consumed). 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. In the process, foods such as corn and wheat are transformed from their original form and combined with salt, fat, sugars, and other ingredients to yield the low-cost, high-energy food and beverage items that line grocery store shelves.

Thus, although food is essential for life, not all foods are created equal. Eating excess quantities of certain foods can actually harm health rather than sustaining life and promoting well-being. Overeating and obesity are on the rise, not only in the United States but 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. This prompts a close consideration of the factors involved in promoting weight gain or thwarting weight loss. In this discussion, 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 calorie deficit. This is why we continue to eat certain foods past the point of satiation, and consume foods like cupcakes and candy that are highly palatable yet not necessarily satiating. Unfortunately, our natural inclination to consume these types of foods collides with the many influences in our modern food environment to ultimately encourage the overconsumption of palatable foods.

Image Credit: “Burgers and Fries from In and Out Burger” by m01229. CC BY NC 2.0 via Flickr.