The effects on plasma lipoproteins of a prudent weight-reducing diet, with or without exercise, in overweight men and women.
BACKGROUND
The National Cholesterol Education Program (NCEP) recommends a low-saturated-fat, low-cholesterol diet, with weight loss if indicated, to correct elevated plasma cholesterol levels. Weight loss accomplished by simple caloric restriction or increased exercise typically increases the level of high-density lipoprotein (HDL) cholesterol. Little is known about the effects on plasma lipoproteins of a hypocaloric NCEP diet with or without exercise in overweight people.


METHODS
We tested the hypothesis that exercise (walking or jogging) will increase HDL cholesterol levels in moderately overweight, sedentary people who adopt a hypocaloric NCEP diet. We randomly assigned 132 men and 132 women 25 to 49 years old to one of three groups: control, hypocaloric NCEP diet, or hypocaloric NCEP diet with exercise. One hundred nineteen of the men and 112 of the women returned for testing after one year.


RESULTS
After one year, the subjects in both intervention groups had reached or closely approached NCEP Step 1 dietary goals and reduced their mean body fat significantly (range of reduction in mean fat weight, 4.0 to 7.8 kg). Weight loss on the NCEP diet alone did not significantly change HDL cholesterol levels in either the men or the women as compared with the subjects in the control group. Plasma levels of HDL cholesterol increased significantly more in the men who exercised and dieted (mean [+/- SE] change, +13 +/- 3 percent) than in the men who only dieted (+2 +/- 3 percent, P less than 0.01) or the men who acted as controls (-4 +/- 2 percent, P less than 0.001). HDL cholesterol levels remained about the same in the women who exercised and dieted (+1 +/- 2 percent); they were higher than in the women who only dieted (-10 +/- 3 percent, P less than 0.01), but not higher than in the controls (-3 +/- 3 percent).


CONCLUSIONS
Regular exercise in overweight men and women enhances the improvement in plasma lipoprotein levels that results from the adoption of a low-saturated-fat, low-cholesterol diet.
Wood
P D
PD
Stanford Center for Research in Disease Prevention, Stanford University School of Medicine, Calif 94304-1583.
Stefanick
M L
ML
Williams
P T
PT
Haskell
W L
WL
D000328:Adult; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D008076:Cholesterol, HDL / Q000097:blood; D003327:Coronary Disease / Q000517:prevention & control; D004038:Diet, Reducing; D004041:Dietary Fats / Q000008:administration & dosage; D002149:Energy Intake; D015444:Exercise; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D014280:Triglycerides / Q000097:blood
D002791:Cholesterol, Dietary; D008076:Cholesterol, HDL; D004041:Dietary Fats; D008074:Lipoproteins; D014280:Triglycerides