The Psychology of Eating: From Healthy to Disordered Behavior

Dieting 141

hope syndrome.” They suggested that making a commitment to change,
regardless of the outcome of this commitment, results in temporary and
immediate rewards. To test this suggestion, subjects either made a com-
mitment to change their weight, a commitment to study more, or no com-
mitment to change. The results showed that for the nondieters making a
commitment resulted in improved mood and self-image. For the dieters,
however, there was a mixed response. The dieters showed an immediate
deterioration in mood which supported the previous research outlined above.
However, they also reported being more hopeful of success. The authors
concluded that this provided some support for the “false hope syndrome”
but suggested that this positive effect on mood varies according to the dietary
history of the individual concerned.

Dieting and weight

Dieting leads to changes in eating behavior, with episodes of both under- and
overeating. It also results in changes in mood and cognitive state. As a con-
sequence of such changes it would also seem likely that dieting would result
in changes in weight. Some research has explored the impact of dieting on
weight fluctuation and weight variability. For example, Heatherton, Polivy,
and Herman (1991) indicated that higher levels of dietary restraint were
related to greater weight fluctuation. This is discussed further in chapter
9, in the context of dieting and obesity treatment. Some research has pointed
to dieting as a contributory factor in the etiology of eating disorders, as
the overeating found in dieters is considered analogous to the binge eating
shown by some anorexics and bulimics (Herman and Polivy, 1988). This
is considered in chapter 10. In addition, dieting is intricately linked with
obesity, both as an attempt to lose weight but also as a possible cause of
weight problems. In particular, dieting behavior at baseline has been
shown to predict greater weight gain in women at follow-up (Klesges, Isbell,
and Klesges, 1992; French et al., 1994). The causes of obesity are discussed
in chapter 8, and the effectiveness of dietary interventions for obesity is
described in chapter 9.
Restraint theory, therefore, suggests the following:

• Dieters aim to eat less as a means to lose weight and change their body
  shape. At times this aim is achieved and they successfully manage to
  restrict their food intake. Dieters therefore sometimes show undereat-
  ing. Sometimes they eat the same as nondieters.