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 (Q(b)). Heterogeneity was examined using the Q and I(2) statistics, and 95% confidence intervals (CI) were also calculated. Statistical significance was set at P ≤ 0.05, while a trend for statistical significance was set between P > 0.05, and ≤0.10. Results. A statistically significant exercise minus control group decrease in non-HDL-C was found for DE (7 ESs, 389 participants, [Formula: see text] mg/dL, 95% CI = -21.7 to -0.6, P = 0.04, Q = 2.4, P = 0.88, I(2) = 0%), a trend for the D group (7 ESs, 402 participants, [Formula: see text] mg/dL, 95% CI = -18.6 to 1.6, P = 0.10, Q = 0.76, P = 0.99, I(2) = 0%), and no change for the E group (7 ESs, 387 participants, [Formula: see text] mg/dL, 95% CI = -7.1 to 13.1, P = 0.56, Q = 0.78, P = 0.99, I(2) = 0%). Overall, no statistically significant between-group differences were found (Q(b) = 4.1, P = 0.12). Conclusions. Diet combined with aerobic exercise may reduce non-HDL-C among adults in some settings.