Classes of fatty acids
The number of diet data points included in the calculations varied
from 102 for total:HDL cholesterol to 114 for total cholesterol
concentration (Table 1). In these diets, the mean intakes of fat,
SFAs, MUFAs, and PUFAs were 34.3% of total daily energy
(range: 4.5–53.0%), 10.2% of energy (2.2–24.4%), 13.5% of
energy (1.5–39.8%), and 8.8% of energy (0.6–28.8%), respectively.
The regression coefficients (Table 1 and Figure 1) showed that
total:HDL cholesterol did not change if SFAs were replaced with
carbohydrates, because total and HDL cholesterol decreased to a
similar extent. The ratio decreased if SFAs or carbohydrates were
replaced with cis unsaturated fatty acids. As shown in
Figure 2, the observed and predicted values for total:HDL cholesterol
were in excellent agreement.
The effects of the classes of fatty acids on serum total, LDL,
and HDL cholesterol concentrations and on serum triacylglycerol
concentrations agreed well with the results of our earlier metaanalysis
(16). The cis MUFAs had a modest but significant LDL
cholesterol–lowering effect relative to carbohydrates. All 3 classes
of fatty acids increased HDL cholesterol relative to carbohydrates.
Unsaturated fatty acids increased HDL cholesterol less than did