What does all this research mean?
The evidence for the causes of obesity is therefore complex and can be summarized as
follows:
There is good evidence for a genetic basis to obesity. The evidence for how this is
expressed is weak.
The prevalence of obesity has increased at a similar rate to decreases in physical
activity.
There is some evidence that the obese exercise less than the non-obese.
The prevalence of obesity has increased at a rate unrelated to the overall decrease in
calorie consumption.
There is no evidence that the obese eat more calories than the non-obese.
The relative increase in fat is parallel to the increase in obesity.
The obese may eat proportionally more fat than the non-obese.
Therefore, the following points would seem likely.
Some individuals have a genetic tendency to be obese.
Obesity is related to under-exercise.
Obesity is related to consuming relatively more fat and relatively less carbohydrates.
Therefore, the causes of obesity remain complex and unclear. Perhaps an integration of
all theories is needed before proper conclusions can be drawn.
OBESITY TREATMENT
Traditional treatment approaches
The traditional treatment approach to obesity was a corrective one, the assumption
being that obesity was a product of overeating and under-activity. Treatment approaches
therefore focused on encouraging the obese to eat ‘normally’ and this consistently
involved putting them on a diet. Stuart (1967) and Stuart and Davis (1972) developed a
behavioural programme for obesity involving monitoring food intake, modifying cues for
inappropriate eating and encouraging self-reward for appropriate behaviour, which was
widely adopted by hospitals and clinics. The programme aimed to encourage eating in
response to physiological hunger and not in response to mood cues such as boredom or
depression, or in response to external cues such as the sight and smell of food or the sight
of other people eating. In 1958, Stunkard concluded his review of the past 30 years’
attempts to promote weight loss in the obese with the statement, ‘Most obese persons will
not stay in treatment for obesity. Of those who stay in treatment, most will not lose
weight, and of those who do lose weight, most will regain it’ (Stunkard 1958). More
recent evaluations of their effectiveness indicate that although traditional behavioural
therapies may lead to initial weight losses of on average 0.5 kg per week (Brownell and
Wadden 1992), ‘weight losses achieved by behavioural treatments for obesity are not
well maintained’.
OBESITY AND CORONARY HEART DISEASE 365