Does dieting contribute to eating disorders?

                                        Does dieting contribute to eating disorders?
                                        by Leigh Brosof, B.A.

​            When was the last time you were on a diet? Most women (and men) have been on a diet at some point in their lives. When we think about dieting in mainstream culture, we often think about celebrities, about fad diets (such as Atkins or paleo), and about counting calories to lose weight leading up to a big event, like a wedding or prom. But is dieting unhealthy? How long do we have to stay on a diet for it to be “bad” for us? And what do we really know about how dieting impacts eating disorders? The truth is that the link between dieting and eating disorders is a lot more complex than we might think. Fortunately, recent research has gone a long way in trying to clear up exactly what dieting is and how it contributes to eating disorders.
 
            Dieting has commonly been regarded as an important factor that may lead to eating disorders (Stice, 2002). Theoretically, dieting can lead to disordered eating behaviors in two ways: physiologically and psychologically (Polivy & Herman, 1985).

•   Physiologically, or on a bodily level, dieting decreases the amount of tryptophan, an amino acid, in our bodies (we tend to think about tryptophan as the thing in turkey that makes us tired after Thanksgiving) (Kaye, Gendall, & Strober, 1998). When we don’t have enough tryptophan, our bodies crave food in order to restore our natural level of tryptophan and can lead to binge eating. Binge eating is when a person eats an unusually large amount of food within a two-hour period accompanied by a feeling of loss of control (American Psychological Association, 2013).

• Psychologically, dieting requires a lot of mental effort in order to restrict how much you are eating, and when this effort is interrupted, eating can then become out of control (Stice, 2002). The question then becomes whether these theoretical pathways actually lead from dieting to an eating disorder.

            In order to really break down why dieting may be harmful, it is necessary to define dieting. Although the definition of dieting seems straightforward, there are actually a lot of different things that are often all called “dieting.” Here, we will define:

• dieting as the real restriction of how many calories you eat a day (i.e., you actually eat less calories per day than needed to maintain current body weight).

• Something else that is related, but different, is dietary restraint: the intent to restrict how many calories you eat per day (i.e., you try to eat less calories than you need per day, but you may or may not actually succeed). This distinction is pertinent because a lot of people say that they are dieting, but not actually succeeding in lowering the amount of calories they are eating.

 
            Research shows that this difference in definition is important. When people report that they are trying to lower the amount of calories they eat (i.e., engaging in dietary restraint), there is a relationship between dieting and disordered eating (Stice, 2002). However, when caloric intake is actually measured, dieting does not predict disordered eating. This indicates that dietary restraint, but not dieting, is what may be important in contributing to disordered eating.
 
           Further studies have supported the idea that dieting might not necessarily be harmful. Some studies even show that dieting can actually lead to less eating disorder symptoms in some instances (Presnell & Stice, 2003; Stice, Martinez, Presnell, &Groesz, 2006; Stice, Presnell, Groesz, & Shaw, 2005). Additionally, other research has suggested that the relationship between dietary restraint and eating disorders may not be completely straightforward either. Many studies have found conflicting results, some indicating that dietary restraint may lead to disordered eating and others showing no relationship between dietary restraint and disordered eating (Stice, 2002). One study investigated these differences by reviewing many of the studies on dietary restraint and eating disorders and concluded that dietary restraint may not actually be harmful either (Schaumberg, Anderson, Anderson, Reilly, & Gorrell, 2016). Obviously, all of these mixed findings can be pretty confusing.
 
           So, if this is the case, can we say anything about dieting and eating disorders? Why do some studies find that dieting (or dietary restraint) is harmful, whereas others do not? Some of the most recent research may have the answer: one study found that it is the type of dieting that may help to untangle the relationship between dieting and disordered eating (Elran-Barak et al., 2015). Extreme dieting, such as fasting, may tend to lead to disordered eating behavior, whereas less intense dieting, such as eating low calories meals, may not tend to lead to disordered eating.
 
          Therefore, when thinking about dieting, it seems important to think about what kind of restriction is occurring. If a person is eating a smaller amount of calories but not overly restricting his or her food intake, it appears that it may not necessarily lead to harmful outcomes. On the other hand, if a person is not eating for many hours at a time and engaging in extreme behavior, then it may be a better indicator that it will lead to bigger problems with eating.
 
           Of course, as discussed, there are a lot of different findings regarding dieting and eating disorders, and researchers will continue to try to investigate the link between the two. At the end of the day, what is most important is that we all eat to fuel ourselves for what our bodies need and to follow a balanced lifestyle. If you are ever worried about your own or a friend’s eating habits, please reach out and talk to someone. Help can be found through the National Eating Disorders Association’s confidential hotline 1-800-931-2237.