Behavioral Changes in Physical Activity

It has frequently been assumed that a behavioral reduction in the energy expended on physical activity helps to counteract the increases in expenditure due to increased body weight, and in some women this leads to saving of energy that largely meets the costs of pregnancy. However, although relatively small changes in activity patterns can potentially result in significant energy savings, there is little evidence that this occurs to a large extent. A possible reason for this is that affluent women are habitually so sedentary that there is little scope for further reduction. In contrast, in developing countries habitual levels of physical activity are high and there is therefore more potential for behavioral reductions. However, many women are likely to be unable to reduce their physical activity because of the constraints imposed by a subsistence livelihood, where farm work is obligatory for survival.

This topic has been one of considerable debate in recent years, particularly since longitudinal studies that have measured total energy expenditure with doubly labeled water have shown that many women increase the energy expended on physical activity during pregnancy, and that any decreases are not sufficient to counterbalance the energy costs of pregnancy due to tissue (fat) deposition and maintenance energy metabolism. It has been recommended that the data used by the World Health Organization should be revised to take account of changes in energy expended on physical activity and to separate these energy costs from those of maintenance and tissue deposition. The Dietary Reference Intakes for the United States and Canada have already incorporated these changes (Table 3).

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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