to assess changes in food intake over the past 50 years. The results from this data-
base illustrate that, although overall calorie consumption increased between 1950
and 1970, since 1970 there has been a distinct decrease in the amount we eat (see
Figure 15.5).
Prentice and Jebb (1995) examined the association between changes in food intake in
terms of energy intake and fat intake and changes in obesity. Their results indicated no
obvious association between the increase in obesity and the changes in food intake (see
Figure 15.6).
Therefore, using population data there appears to be no relationship between
changes in food intake and changes in obesity.Do the obese eat for different reasons than the non-obese? Throughout the
1960s and 1970s theories of eating behaviour emphasized the role of food intake in
predicting weight. Original studies of obesity were based on the assumption that the
obese ate for different reasons than people of normal weight (Ferster et al. 1962).
Schachter’s externality theory suggested that, although all people were responsive to
environmental stimuli such as the sight, taste and smell of food, and that such stimuli
might cause overeating, the obese were highly and sometimes uncontrollably responsive
to external cues. It was argued that normal weight individuals mainly ate as a response
to internal cues (e.g. hunger, satiety) and obese individuals tended to be under-
responsive to their internal cues and over-responsive to external cues. Within this per-
spective, research examined the eating behaviour and eating style of the obese and non-
obese in response to external cues such as the time of day, the sight of food, the taste of
food and the number and salience of food cues (e.g. Schachter 1968; Schachter and
Gross 1968; Schachter and Rodin 1974). The results from these studies produced fairly
inconsistent results. Therefore, research also examined whether the obese ate more than
the non-obese.Do the obese eat more than the non-obese? Research exploring the amount
eaten by the obese has either focused on the amount consumed per se or on the type of
food consumed.
Because it was believed that the obese ate for different reasons than the non-obese it
was also believed that they ate more. Research therefore explored the food intake of the
obese in restaurants and at home, and examined what food they bought. For example,
Coates et al. (1978) suggested that perhaps the obese were overeating at home and went
into the homes of 60 middle-class families to examine what was stored in their
cupboards. They weighed all members of the families and found no relationship between
body size and the mass and type of food they consumed at home. In an attempt to clarify
the problem of whether the obese eat more than the non-obese, Spitzer and Rodin (1981)
examined the research into eating behaviour and suggested that ‘of twenty nine studies
examining the effects of body weight on amount eaten in laboratory studies... only nine
reported that overweight subjects ate significantly more than their lean counterparts’.
Therefore, the answer to the question ‘do the obese eat more/differently to the non-
obese?’ appears to be ‘no’; the obese do not necessarily overeat (compared with others). If
overeating is defined as ‘compared with what the body needs’, it could be argued that the362 HEALTH PSYCHOLOGY