The Psychology of Eating: From Healthy to Disordered Behavior

Obesity Treatment 191

benefits. Alternative treatment approaches have therefore been developed,
including exercise, drugs, and surgery. Drugs and surgery represent non-
psychological approaches to managing obesity. Yet evaluations of their effec-
tiveness indicate that they have psychological implications for the individual.
These implications will be explored as a means to understand how
behaviorally orientated interventions can be improved.

Exercise-based treatments of obesity

Over the past few years exercise has played an increasingly important role
in the treatment of obesity, either as an adjunct to dieting or as a stand-
alone approach. For example, Brownell (1995, 1998) argued that exercise
should be central to any intervention and that “it would be difficult to argue
that any factor is more important than exercise” (1995). The impact of
exercise has been explored in terms of its effects on weight loss, weight
maintenance, and overall physical and psychological health.

Exercise and weight loss
Exercise can take many forms, including structured sports such as tennis
or aerobics, and incidental physical activity such as stair-climbing. As a result
of this variability, assessments of the effectiveness of exercise as a treatment
for obesity are problematic. Several reviews and meta-analyses, however,
have been carried out. Ballor and Poehlman (1994) examined 46 diet-based
weight loss programs published between 1964 and 1991 and concluded that
adding exercise to diet-based treatments had no impact on changes in body
weight or fat mass. Garrow and Summerbell (1995) conducted a meta-
analysis and calculated that over 30 weeks, exercise added 3 kg extra weight
loss in men, and over 12 weeks exercise added 1.4 kg weight loss for women.
They also concluded that exercise resulted in greater loss of fat mass and
improved preservation of fat-free mass, although Kopelman (1997) has argued
that the impact of exercise on fat reduction remains unsupported by a
substantial evidence base. Fox (1999) reviewed the literature exploring
exercise and weight loss and concluded that “aerobic exercise cannot com-
pete with dietary methods for rapid weight loss” but that it should be
“considered as an accompaniment to a moderate dietary regime” (p. 166).

Exercise and weight maintenance
Exercise seems to have a more important role to play in weight mainte-
nance. For example, Pavlou, Krey, and Steffee (1989) randomly allocated
male participants to receive either a dietary intervention or diet plus exercise,