166 Obesity
(i.e., some people who become obese could be active and those who are
thin could be inactive).
In an alternative approach to assessing the relationship between activity
and obesity, research has used prospective designs to explore the impact
of changes in activity levels on changes in body weight. A large Finnish
study of 12,000 adults examined the association between levels of physical
activity and excess weight gain over a 5-year follow-up (Rissanen et al., 1991).
The results showed that lower levels of activity were a greater risk factor
for weight gain than any other baseline measures. Similarly, Haapenen et al.
(1997) monitored 5,000 working adults in Finland over a 10-year period
and examined their leisure time physical activity and subsequent weight
Figure 8.4 Changes in physical activity and obesity. (Source: A.M. Prentice
and S.A. Jebb, Obesity in Britain: Gluttony or sloth? British Medical Journal,
311 (1995), pp. 437–9, reprinted by permission of The British Medical Journal
Publishing Group.)
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