The future catches up: a medical school curriculum in health economics.

Medical school curricula for too long have ignored the obvious and important changes in the economics and delivery of health care in the United States. Medical students, who become the practicing physicians of the future, and their patients have suffered because of this academic malaise. Most new physicians are even more confused than their patients about how to navigate outpatient managed care, how to practice efficiently (after being taught that more is better), and how to uphold their sacred trust with their patients in the context of institutionally based medicine. After summarizing relevant historical events, we discuss how we hope to begin making up for lost time by tackling the issue of necessary curriculum change at the University of Pennsylvania Health System.

Effects of weight cycling on the resting energy expenditure and body composition of obese women.

OBJECTIVE: Numerous reports have suggested that cycles of weight loss and regain (i.e., weight cycling) are associated with adverse health consequences, a concern that may lead some obese individuals to forgo weight control efforts. The present study examined whether weight cycling was associated with a reduction in resting energy expenditure (REE) and with increases in both total and upper body fat. METHOD: REE, body composition, and body fat distribution were measured before and after weight loss, and following full weight regain, in 12 women who before treatment had a mean (+/- SEM) age of 38.8 +/- 3.4 years and weight of 98.0 +/- 3.2 kg. RESULTS: At the end of treatment, patients lost 18.9 +/- 2.6 kg which was comprised of significant decreases in body fat and fat-free mass of 15.2 +/- 2.2 and 3.7 +/- 0.8 kg, respectively (both ps < .001). REE also fell during this time from 1,631 +/- 82 to 1,501 +/- 51 kcal/d (p < .03). All of these measures, however, returned to their baseline values when patients regained their lost weight. Body fat distribution was unchanged throughout the study. DISCUSSION: These results do not support claims that weight cycling adversely affects REE, body composition, or body fat distribution.

The energy cost of walking before and after significant weight loss.

The purpose of this study was to determine whether significant weight loss reduced the energy cost of activity more than that expected based on decreased body weight. Standing energy expenditure was measured and subtracted from the total energy cost of walking to determine ambulatory energy expenditure (AEE). The energy cost of walking was determined in 11 obese women at baseline, week 9 [after 8 wk of a 1758-3349 kJ.d-1 diet], and week 22 (after 2 wk of weight stability). AEE accounted for 80% of the energy cost of walking. Body weight was the principal determinant of AEE, but the relationship was not 1:1. Subjects reduced body weight by 13% at week 9 and 21% at week 22. Analyses which controlled for the relationship between AEE and weight at baseline, showed no change in AEE at week 9. By contrast, at week 22, AEE was reduced more than expected based on a lower body weight. These findings suggest that after significant weight loss, reduced-obese persons will expend less energy for the same activity, even after accounting for the decrease in body weight. These data also suggest that weight-based estimates of exercise energy expenditure may be inappropriate after significant weight loss.

Relationship of dieting history to resting metabolic rate, body composition, eating behavior, and subsequent weight loss.

This study examined the relationship of dieting history to resting metabolic rate, body composition, and subsequent weight loss in 50 obese women. A preliminary study showed that the women were able to report with satisfactory reliability the number of diets in which they had engaged (mean = 4.9 +/- 0.5), as well as the total weight loss resulting from these diets (mean = 55.9 +/- 6.0 kg). We found no evidence that weight cycling, as measured by either of these variables, was associated at baseline with a reduced resting metabolic rate or an increased percentage of body fat. Nor did we find that weight cycling was associated with smaller weight losses in a prospective trial in which subjects were treated by very-low-calorie diet and behavior therapy. The clinical implications of these findings are discussed, as are the methodological problems encountered in conducting research on this topic.

A controlled comparison of three very-low-calorie diets: effects on weight, body composition, and symptoms.

To determine the optimal energy intake of very-low-calorie diets (VLCDs), 76 obese women were randomly assigned, in a double-blind fashion, to one of three liquid-formula diets: 1758 kJ/d (420 kcal/d), 2763 kJ/d (660 kcal/d), or 3349 kJ/d (800 kcal/d). Weight, body composition, symptoms, mood, and acceptability of the diet were assessed throughout the 6-mo study. There were no significant differences in weight losses or changes in body composition among the three dietary conditions at the end of treatment, nor were there significant differences among conditions in acceptability of the diet, symptoms, or mood. These results suggest that there is no clinical advantage to using VLCDs that provide less than 3349 kJ/d (800 kcal/d).