Efficacy of aerobic exercise and a prudent diet for improving selected lipids and lipoproteins in adults: a meta-analysis of randomized controlled trials.
Study Goal
The researchers aimed to determine the effects of aerobic exercise combined with a prudent diet on lipid and lipoprotein concentrations (TC, HDL-C, LDL-C, TG) in adults.
Results Summary
The study found statistically significant reductions in TC, TC:HDL-C, LDL-C, and TG, but not HDL-C. Limitations included missing variance statistics for non-HDL-C and a need for additional studies with intention-to-treat analysis.
Population
Adults ≥ 18 years of age (559 participants: 282 intervention, 277 control).
Effective Dosage
Diet recommendations: saturated/trans fat intake <10% of total calories, cholesterol <300 mg/day, fiber ≥25 g/day (women) or ≥35 g/day (men).
Duration
Intervention ≥4 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
aerobic exercise combined with a prudent diet | decrease | total cholesterol (TC) | adults | -15.5 mg/dl | Statistically significant intervention minus control reductions were found | #1 |
aerobic exercise combined with a prudent diet | decrease | ratio of TC to HDL-C (TC:HDL-C) | adults | -0.4 mg/dl | Statistically significant intervention minus control reductions were found | #2 |
aerobic exercise combined with a prudent diet | decrease | low-density lipoprotein cholesterol (LDL-C) | adults | -9.2 mg/dl | Statistically significant intervention minus control reductions were found | #3 |
aerobic exercise combined with a prudent diet | decrease | triglycerides (TG) | adults | -10.6 mg/dl | Statistically significant intervention minus control reductions were found | #4 |
aerobic exercise combined with a prudent diet | no change | high-density lipoprotein cholesterol (HDL-C) | adults | -0.5 mg/dl | not | #5 |
aerobic exercise combined with a prudent diet | decrease | total cholesterol (TC) | adults | 7.5% | Changes were equivalent to reductions of | #6 |
aerobic exercise combined with a prudent diet | decrease | ratio of TC to HDL-C (TC:HDL-C) | adults | 6.6% | Changes were equivalent to reductions of | #7 |
aerobic exercise combined with a prudent diet | decrease | low-density lipoprotein cholesterol (LDL-C) | adults | 7.2% | Changes were equivalent to reductions of | #8 |
aerobic exercise combined with a prudent diet | decrease | triglycerides (TG) | adults | 18.2% | Changes were equivalent to reductions of | #9 |
aerobic exercise combined with a prudent diet | decrease | TC, TC:HDL-C, LDL-C and TG | adults | - | is highly efficacious for improving | #10 |
aerobic exercise combined with a prudent diet | no change | HDL-C concentrations | adults | - | not | #11 |
BACKGROUND: Studies addressing the effects of aerobic exercise and a prudent diet on lipid and lipoprotein concentrations in adults have reached conflicting conclusions. The purpose of this study was to determine the effects of aerobic exercise combined with a prudent diet on lipid and lipoprotein concentrations in adults. METHODS: Studies were located by searching nine electronic databases, cross-referencing, and expert review. Two independent reviewers selected studies that met the following criteria: (1) randomized controlled trials, (2) aerobic exercise combined with diet recommendations (saturated/trans fat intake less than 10% of total calories and cholesterol less than 300 mg/day and/or fiber intake ≥ 25 g/day in women and ≥ 35 grams per day in men), (3) intervention ≥ 4 weeks, (4) humans ≥ 18 years of age, (5) published studies, including dissertations and Master's theses, (6) studies published in any language, (7) studies published between January 1, 1955 and May 1, 2009, (8) assessment of one or more of the following lipid and lipoprotein concentrations: total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), ratio of TC to HDL-C, non-HDL-C, low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG). Two reviewers independently extracted all data. Random-effects models that account for heterogeneity and 95% confidence intervals were used to pool findings. RESULTS: Of the 1,401 citations reviewed, six studies representing 16 groups (8 intervention, 8 control) and up to 559 men and women (282 intervention, 277 control) met the criteria for analysis. Statistically significant intervention minus control reductions were found for TC (-15.5 mg/dl, 95% CI, -20.3 to -10.7), TC:HDL-C (-0.4 mg/dl, 95% CI, -0.7 to -0.2), LDL-C (-9.2 mg/dl, 95% CI, -12.7 to -5.8) and TG (-10.6 mg/dl, 95% CI, -17.2 to -4.0) but not HDL-C (-0.5 mg/dl, 95% CI, -4.0 to 3.1). Changes were equivalent to reductions of 7.5%, 6.6%, 7.2% and 18.2% respectively, for TC, TC:HDL-C, LDL-C and TG. Because of missing variance statistics, non-HDL-C was excluded. CONCLUSIONS: Aerobic exercise combined with a prudent diet is highly efficacious for improving TC, TC:HDL-C, LDL-C and TG, but not HDL-C concentrations, in adults. However, additional studies are needed, including effectiveness studies using intention-to-treat analysis.