Why Are You Eating That?


Eating behavior is determined by numerous factors: ideational values, social gatherings, pleasure systems, habit, convenience and so on. Understanding why we eat what we eat can have a positive impact on controlling eating behavior. Eating behavior is an important factor involved with bodyweight and health issues. In this review a variety of factors that influence eating behavior will be discussed. However, the intent here is not an exhaustive look at the myriad of factors that influence eating behavior. But, rather a brief look how environmental factors influence eating behavior, factors involved with development of food preferences and whether or not we are aware of the influence these environmental factors have on eating behavior. In addition, suggestions will be provided regarding the development of a comprehensive model for the treatment of obesity. Conceivably people do not need more information about food’s energy and nutrient contents, but more information about their own behavioral tendencies and how they may be more easily managed in an effort to adhere to appropriate eating strategies.

This article is concise version of the review paper- Why Are You Eating That: Food likes, environmental factors and awareness of eating behavior (47 pages- double spaced). With purchase of any product receive a free PDF copy, upon request, of the full review.

The importance of food and its relation to our everyday functioning cannot be overstated. Eating behavior is determined by numerous factors: ideational values, social gatherings, pleasure systems, habit, convenience and so on. Food progresses from being a source of nutrition, to a sensory pleasure, an aesthetic experience, a source of meaning, and often a moral entity (Rozin, 1996). Understanding why we eat what we eat can have a positive impact on controlling eating behavior.

There are a plethora of factors that contribute to eating behavior. These factors are often categorized as internal (biological, physiological) or external (environmental) factors or cues (Vartanian, Herman, & Wansink, 2008; Eertmans, Baeyens, & Van den Bergh, 2001; Levitsky, 2005; Wansink, 2004; Wansink, 2009). In this paper a variety of factors that influence eating behavior will be discussed.

It has been suggested that we are often unaware of some of the external factors that influence eating behavior (Wansink, 2006; Vartaninan et al., 2008). There is a moderate amount of research that shows environmental factors have a robust influence on eating behavior (Epstein et al., 2009; Remick, Polivy, & Pliner, 2009; Rozin, Kabnick, Fischler, & Shields, 2003). Some researchers have suggested that environmental factors may play a larger role in eating behavior than internal factors- hunger, satiety, flavor, macronutrient content, etc.- (Wansink, Payne, & Chandon, 2007; Levitsky, 2005; Wansink & Junyong, 2005). Are these factors below our awareness or do we fail to acknowledge these factors?

Nisbett and Wilson suggested that many of our behaviors and cognitions are influenced by unconscious factors (Nisbett & Wilson, 1977). Through a review of the existing literature and set of their own experiments they found that people often fail to accurately report the presence of various stimuli that affect their behavior and thinking.

Food Likes / Dislikes

Food likes and dislikes are often thought to play a big role in eating behaviors. The pleasure we derive from food may be one of the most important factors contributing to food intake (Eertmans, et al., 2001; Rozin & Zellner, 1985; Rozin, 1990). Interviews with customers in supermarkets and restaurants have shown that people consider the sensory properties of food an important value influencing their choice of food purchased (Furst, Connors, Bisogni, Sobal, & Winter Falk, 1996). The influence of food liking on eating behavior has been demonstrated in several areas, including meal duration, rate of eating, amount eaten, (Spitzer & Rodin, 1981) and frequency of eating (Woodward et al., 1996). In children facial cues are often used as markers of food likes / dislikes (Beauchamp & Mennella, 2009). Discrepancies have been reported between food liking and food consumption (Eertmans et al., 2001).

The evidence concerning the impact of food likes on eating behavior is not completely decisive, but the preponderance of evidence suggests that food likes play a major role in eating behavior (Eertmans et al., 2001; Beauchamp & Mennella, 2009; Rozin, 1990). It is important to note, food liking is relatively unstable and is one of many factors that influence eating behaviors (Donaldson, Bennett, Baic, & Melichair, 2009). But, this doesn’t negate the importance of liking and its contribution to eating behavior.

External (environmental) Factors

At one time it was widely assumed people ate when they were hungry and stopped when they were full- via physiological signals. More recently, a variety of factors have been shown to influence food intake, e.g. cultural, influences of the food industry, environmental factors and so on (Vartanian et al., 2008; Rozin, 1996; Wansink et al., 2009). Of those factors, external factors appear to be one of the most important influences on eating behavior. There is a substantial amount of evidence showing that external factors can influence people’s eating behavior (Remick et al., 2009; Herman, Koenig-Nobert, Peterson, & Polivy, 2005) Some of these external factors affecting eating behavior include portion size, socializing, variety, labeling and plate shape (Wansink, 2004). These factors often work together or with other factors to influence food intake. Primarily, external factors affect our eating behaviors by influencing consumption norms or they interfere with our ability to monitor how much we have eaten (Wansink et al., 2009).

Evidence indicates that the size of a package, the size of portion servings in kitchens, and in restaurants can lead to increased consumption (Wansink, 1996; Sobal & Wansink, 2007; Diliberti, Bordi, Conklin, Roe, & Rolls, 2004). The larger the variety of food the more food consumed (Rolls, Rolls, Rowe, Sweeney, 1981a.). The premise that increasing the variety of food can increase consumption has been found in bother genders and across a wide range of ages (Wansink, 2004). People tend to eat a similar amount as the person or persons eating with them (Herman et al., 2005; Wansink, 2004). That is, the presence and behavior of others has a strong influence on people’s eating behaviors. People often approximate the intake level of their eating partner. Snack food advertising has been shown to affect eating behavior. Seeing or smelling a food can lead to consumption (Rothman et al., 2009; Wansink, 2004). As an example, workers ate over five more chocolate kisses per day when a container full of candy was on their desks rather when it was further away and less noticeable (Painter, Wanskink, & Hieggelke, 2002).

Other Factors

Evidence indicates the hormones leptin, ghrelin, peptide YY, and cholecystokinins have a role in the regulation of appetite, which influences eating behavior (Orr & Davy, 2005). These hormones affect important regions of the brain that are involved with the regulation of food intake and energy balance. Macronutrient content has also been shown to be influential; protein is generally found to be more satiating than fat or carbohydrate. Factors that have been shown to influence eating behavior in addition to the ones discussed in this paper include gastric signals, cost, cultural norms, food availability, emotional factors, additional neurochemical factors (Freedman, King, & Kennedy, 2001) energy deficit (Levitsky, 2005), nutrient deficiencies (Rozin, 1990) and ideologies (Rozin et al., 2004).

Awareness of factors influencing eating behaviors

Vartanian et al (2008) point out that it is not clear as to whether or not studies that supposedly demonstrate a lack of awareness actually demonstrate awareness or demonstrate a reluctance to acknowledge these external factors. This distinction is important and has important implications. If we are not aware of factors influencing eating behaviors then it will be difficult to control those behaviors. In order to make the distinction between awareness and acknowledgement further research and the development of more stringent procedures for measuring awareness are necessary.

In some studies self-report measures have been used to investigate awareness. However, in many studies looking at external factors no specific approach to measure awareness was made, rather, unawareness was suggested post-hoc. It is a compilation of evidence that has led to the suggestion we are unaware of external factors influencing food intake. It is likely that some of the evidence from this line of research may be indicative of absence of awareness.


A wide array of factors influences eating behavior, and some of them has been mentioned here. It appears that food likes / dislikes play an important role in eating behavior. External factors also influence eating behavior.

It is often suggested that we are not aware of many factors that influence eating behavior. Research in other areas has demonstrated that behaviors can be influenced by factors that are below awareness. Research on awareness & eating behavior is lacking. Research that is cited as evidence for lack of awareness is often research that was conducted to investigate another topic (e.g. external factors and influence on eating behavior). I am in agreement with what Brunstrom (2004) said in regards to awareness and eating behavior, “in the majority of studies, awareness has not been explored systematically, and in some cases, it has been ignored.”

References are available upon request

Post- Why Are You Eating That? Food likes, environmental factors and awareness of eating behavior:

In a recent study conducted at Eastern Kentucky University (Hale & Varakin, In Press) researchers investigated whether or not participants would eat more M&M’s from a bowl containing a single color versus a bowl containing a variety of colors. We were also interested in whether or not people who eat more M&M’s from the multi-color bowl would indicate they ate more due to variety. The results showed participants ate more M&M’s from the multi-color bowl than the single-color bowl. Importantly, participants who ate more from the multi-color bowl were more likely to mention variety as a reason for the increased consumption than those who did not eat more from the multi-color bowl. The results suggest there is a relationship between actual consumption and people’s reports of consumption.

Jamie Hale