The role of dieting in mood and cognitive changes

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EATING BEHAVIOUR 163
this behaviour results in weight fluctuations but not actual weight loss. Thus, actual
weight loss is limited by compensatory overeating. Heatherton et al. (1988: 20) argued
that ‘the restrained eater who is exclusively restrained . . . is not representative of
restrained eaters in general, whereas the restrained eater who occasionally splurges is’.
Ogden (1993) examined the concept of restraint as assessed by a variety of measures
and found that high scorers on measures of restraint were characterized by both successful and failed restriction, suggesting that restrained eating is best characterized as an
intention which is only sporadically realized. Therefore, ‘to diet’ is probably best understood as ‘attempting to lose weight but not doing so’ and ‘attempting to eat less which
often results in eating more’.
The role of dieting in mood and cognitive changes
A classic study by Keys et al. (1950) suggested that overeating is not the only possible
consequence of restricting food intake. The study involved 36 healthy non-dieting men
who were conscientious objectors from the Korean War. They received a carefully controlled daily food intake of approximately half their normal intake for a period of 12
weeks, and consequently lost 25 per cent of their original body weight. Keys stated that
they developed a preoccupation with food, often resulting in hoarding or stealing it. They
showed an inability to concentrate and mood changes, with depression and apathy being
common. At the end of the period of dieting, the men were allowed to eat freely. They
often ate continuously and reported loss of control over their eating behaviour sometimes resulting in binge eating. The authors concluded that these effects were probably
due to the restriction of their diet. To examine the effects of dieting without extreme
weight loss, Warren and Cooper (1988) carried out a controlled study for a two-week
period and found that food restriction resulted in increased preoccupation with food. In
a further study, Ogden (1995a) monitored the effects of self-imposed dieting over a
six-week period and reported increased depression and preoccupation with food. These
results suggest that dieting can have several negative consequences and that these
changes are possibly involved in causing overeating.
Restraint theory therefore suggests that:
I 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 undereating. Sometimes they eat the same as non
dieters.
I Dieters, however, also show episodes of overeating, particularly in response to triggers
such as high calorie preloads, anxiety or smoking abstinence.
I This overeating can be understood in terms of the transgression of boundaries, shifts
in cognitive set, mood modification, a response to denial, an escape from awareness,
a lapse or changes in self-control. Increasing or promoting dieting can result in an
increased preoccupation with food, increased depression and paradoxically, increased
eating behaviour.
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