Health Psychology : a Textbook

of the satiety boundary are activated. The boundary model proposes a form of dual

regulation, with food intake limited either by the diet boundary or the satiety boundary.

The boundary model has also been used to examine differences between dieters, binge

eaters, anorexics and normal eaters. This comparison is shown in Figure 6.7.

iii) Cognitive shifts The overeating found in dieters has also been understood in

terms of shifts in the individual’s cognitive set. Primarily this has been described in

terms of a breakdown in the dieter’s self control reflecting a ‘motivational collapse’ and

a state of giving in to the overpowering drives to eat (Polivy and Herman

1983). Ogden and Wardle (1991) analysed the cognitive set of the disinhibited dieter

and suggested that such a collapse in self control reflected a passive model of overeating

and that the ‘what the hell effect’ as described by Herman and Polivy (1984) contained

elements of passivity in terms of factors such as ‘giving in’, ‘resignation’ and ‘passivity’.

In particular, interviews with restrained and unrestrained eaters revealed that many

restrained eaters reported passive cognitions after a high calorie preload including

thoughts such as ‘I’m going to give into any urges I’ve got’ and ‘I can’t be bothered,

it’s too much effort to stop eating’ (Ogden and Wardle 1991). In line with this

model of overeating, Glynn and Ruderman (1986) developed the eating self-efficacy

Fig. 6-7 A comparison of the boundaries for different types of eaters

156 HEALTH PSYCHOLOGY