Purpose. To use the meta-analytic approach to examine the effects of diet (D), aerobic exercise (E), or both (DE) on non-high-density lipoprotein cholesterol (non-HDL-C) in adults. Methods. Randomized controlled trials in adults ≥18 years of age were included. A mixed-effect model was used to combine effect size (ES) results within each subgroup and to compare subgroups (). Heterogeneity was examined using the and statistics, and 95% confidence intervals (CI) were also calculated. Statistical significance was set at , while a trend for statistical significance was set between , and ≤0.10. Results. A statistically significant exercise minus control group decrease in non-HDL-C was found for DE (7 ESs, 389 participants, mg/dL, 95% to −0.6, , , , %), a trend for the D group (7 ESs, 402 participants, mg/dL, 95% to 1.6, , , , %), and no change for the E group (7 ESs, 387 participants, mg/dL, 95% to 13.1, , , , %). Overall, no statistically significant between-group differences were found (, ). Conclusions. Diet combined with aerobic exercise may reduce non-HDL-C among adults in some settings.