Ratings for the strength of the recommendations (Strong, Fair, Weak, Consensus, Insufficient Evidence), conclusion grades (I-V), and statement labels (Conditional versus Imperative) are defined at the end of "Major Recommendations"
Recommendation 1. Referral to a Registered Dietitian for Medical Nutrition Therapy (MNT) and Disorders of Lipid Metabolism
(R1.1) Referral to a registered dietitian for MNT is recommended whenever an individual has an abnormal lipid profile, based on the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III Risk category and low-density lipoprotein cholesterol (LDL-C) goals, or has coronary heart disease (CHD). A planned initial visit lasting from 45 to 90 minutes and at least two to six planned follow-up visits (30 to 60 minutes each, with a registered dietitian [RD]) can lead to improved dietary pattern; improved lipid profile; reduced plasma total cholesterol, LDL-C, and triglycerides; and improved weight status.
Strong
Conditional
(R1.2) The number and duration of visits in the course of MNT will need to be greater if the client is in a higher risk category, if there is a large number of therapeutic lifestyle changes (TLC) that need to be made, and if the individual is not motivated to make TLC changes. Increasing the number of visits and length of time spent with a dietitian can improve serum lipid levels and cardiovascular disease (CVD) risk.
Fair
Conditional
(R1.3) Re-evaluate the dosage and necessity of lipid-lowering medications throughout the course of MNT. MNT may successfully improve the lipid levels to the point where medication doses can be lowered or discontinued.
Fair
Imperative
Recommendations were based on evidence conclusion statements with Grades I, III, and V
Recommendation 2. Body Mass Index (BMI), Waist Circumference or Waist-to-Hip Ratio (WHR) and Disorders of Lipid Metabolism
(R2.1) In addition to BMI, use waist circumference or WHR to assess obesity and CVD risk. BMI alone is not a good predictor of CVD risk in persons over 65 years old. Increases in waist circumference, WHR, and BMI are associated with CHD events and CVD mortality.
Strong
Imperative
Recommendations were based on evidence conclusion statements with Grades II and III
Recommendation 3. Major Dietary Fat Components and Lipid Metabolism Disorders
(R3.1) The cardioprotective dietary pattern should be tailored to the individual's needs to provide a fat intake of 25 to 35% of calories, <7% of calories from saturated fat and trans-fatty acids, and <200 mg cholesterol per day. This dietary pattern can lower LDL-cholesterol up to 16% and decrease risk of CHD.
Strong
Imperative
(R3.2) The cardioprotective dietary pattern should be as low as possible in saturated and trans fatty acids and less than 7% of calories. For individuals at their appropriate body weight without elevated LDL-cholesterol or triglyceride levels and with normal HDL-cholesterol levels, saturated fatty acid calories could be replaced by unsaturated fat and/or complex carbohydrate. Replacing saturated fats with mono- and polyunsaturated fat lowers LDL-cholesterol, without lowering HDL-cholesterol or increasing triglycerides, although the ideal replacement percentages are unclear. Research is needed on how best to titrate these recommendations.
Strong
Imperative
Recommendations were based on evidence conclusion statements with Grade I
Recommendation 4. Trans-Fatty Acid Intake and Disorders of Lipid Metabolism
(R4.1) Trans-fatty acids consumption should be as low as possible. A cardioprotective dietary pattern should contain less than 7% of calories from saturated fat and trans-fatty acids. Trans-fatty acids raise total cholesterol (TC) and LDL-C and may decrease HDL-C, thereby increasing the TC/HDL-C and LDL-C/HDL-C ratios. Increasing trans-fatty acid intake increases risk of CHD events.
Strong
Imperative
Recommendation was based on evidence conclusion statements with Grades I and II
Recommendation 5. Omega-3 Fatty Acids and Disorders of Lipid Metabolism
(R5.1) If consistent with patient preference and not contraindicated by risks or harms, omega-3 fatty acids, preferably from both marine and plant sources, should be included in a cardioprotective diet. Consuming dietary sources of omega-3 fatty acids from fish (two 4-oz servings of fish per week [preferably fatty fish such as mackerel, salmon, herring, trout, sardines, or tuna]) and plant-based foods of 1.5g alpha-linolenic acids (1 Tb canola or walnut oil, 0.5 Tb ground flax seed, <1 tsp flaxseed oil) are recommended. Consumption of increased omega-3 fatty acids is associated with a decreased risk of death from cardiac events and non-fatal myocardial infarctions (MIs). Some fatty fish can be high in methylmercury and should be limited, according to the US Food and Drug Administration (FDA).
Fair
Conditional
(R5.2) If an individual does not eat food sources of omega-3 fatty acids, then 1g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acid supplements may be recommended for secondary prevention.
Fair
Conditional
Recommendations were based on evidence conclusion statements with Grades II and III
Recommendation 6. Carbohydrates and Protein, Including Dietary Fiber, and Disorders of Lipid Metabolism
(R6.1) The cardioprotective dietary pattern should be as low as possible in saturated and trans fatty acids and less than 7% of calories. Saturated fatty acid and trans-fatty acid calories may be replaced by unsaturated fatty acids, complex carbohydrates and protein. However, studies to determine the ideal percentages of these macronutrients as replacements for saturated fat are needed.
Strong
Imperative
(R6.2) Include foods containing 25 to 30 grams of fiber per day, with special emphasis on soluble fiber sources (7 to 13 grams), as part of a cardioprotective diet. Foods rich in soluble fiber include: fruits, vegetables, and whole grains, especially high-fiber cereals, oatmeal, beans, and prunes. Risk factors associated with CHD (blood pressure, lipoprotein subclasses and particle sizes, insulin resistance, and post-prandial glucose) and CVD (fatal and non-fatal MI and stroke) are decreased as dietary fiber intake increases. Diets high in total and soluble fiber, as part of a cardioprotective diet, can further reduce TC by 2 to 3% and LDL up to 7%.
Strong
Imperative
Recommendations were based on evidence conclusion statements with Grades I, II, and III
Recommendation 7. Plant Stanols and Sterols and Disorders of Lipid Metabolism
(R7.1) If consistent with patient preference and not contraindicated by risks or harms, then plant sterol and stanol ester enriched foods consumed two or three times per day, for a total consumption of two or three grams per day, may be used in addition to a cardioprotective diet to further lower TC by 4 to 11% and LDL-C by 7 to 15%. For maximal effectiveness, foods containing plant sterols and stanols (spreads, juices, yogurts) should be eaten with other foods. To prevent weight gain, isocalorically substitute stanol- and sterol-enriched foods for other foods. Plant stanols and sterols are effective in people taking statin drugs.
Strong
Conditional
Recommendation was based on evidence conclusion statements with Grades I, II, and III
Recommendation 8. Soy Protein and Disorders of Lipid Metabolism
(R8.1) If consistent with patient preference and not contraindicated by risks/harms, then soy (e.g., isolated soy protein, textured soy, tofu) may be included as part of a cardioprotective diet. Consuming 26 to 50g of soy protein per day in place of animal protein can reduce TC by 0 to 20% and LDL-C by 4 to 24%. Evidence is insufficient to establish a beneficial role of isoflavones as an independent component.
Fair
Conditional
Recommendation was based on evidence conclusion statements with Grades II and III
Recommendation 9. Nuts, Disorders of Lipid Metabolism, and CHD
(R9.1) If consistent with patient preference and not contraindicated by risks or harms, then nuts (walnuts, almonds, peanuts, macadamia, pistachios, and pecans) may be isocalorically incorporated into a cardioprotective dietary pattern. Consuming five ounces of nuts per week is associated with a reduced risk of CHD. Because of their beneficial fatty acid profile as well as other nutritional components, nuts may be incorporated into a cardioprotective dietary pattern low in saturated fat and cholesterol to reduce TC by 4 to 21% and LDL-C by 6 to 29%.
Fair
Conditional
Recommendation was based on evidence conclusion statements with Grade II
Recommendation 10. Alcohol Intake and Disorders of Lipid Metabolism
(R10.1) Current evidence does not justify encouraging those who do not drink alcohol to start doing so. If a patient currently drinks alcohol, and if not contraindicated, then a maximum of one drink per day for women and up to two drinks per day for men may be incorporated into a cardioprotective dietary pattern with meals within recommended calorie levels. This level of alcohol consumption has been demonstrated to be associated with a reduced risk of CVD.
There is no evidence that one type of alcohol is better than another.
Fair
Conditional
Recommendations were based on evidence conclusion statements with Grades II and III
Recommendation 11. Antioxidants (Vitamin E, Vitamin C, and Beta-Carotene), Disorders of Lipid Metabolism, and CHD
(R11.1) Antioxidants such as vitamin E, vitamin C, and beta-carotene (or carotenoids) should be specifically planned into a cardioprotective dietary pattern. Antioxidant-rich fruits, vegetables, and whole grains have been shown to be associated with reduced disease risk.
Fair
Imperative
Recommendations were based on evidence conclusion statements with Grade III
(R11.2) Vitamin E, vitamin C, and beta-carotene supplements should not be recommended to reduce the risk of CVD. These supplements have shown no protection for CVD events or mortality.
Strong
Imperative
Recommendation was based on evidence conclusion statements with Grade I and II
(R11.3) Supplemental vitamin E, vitamin C, beta-carotene, and selenium should not be taken with a simvastatin/niacin drug combination. Supplemental beta-carotene cannot be recommended in individuals with a smoking habit. Research indicates that in these situations there is an increased risk.
Fair
Imperative
Recommendation was based on evidence conclusion statements with Grade II
Recommendation 12. Homocysteine, Folate, or Vitamin B6 or B12 and Prevention of CHD
(R12.1) Folate, vitamin B6, and vitamin B12 should be planned into the cardioprotective dietary pattern to meet the DRI. If an individual has high serum homocysteine levels (usually greater than 13 umol/L), these B vitamins may lower serum homocysteine levels by 17 to 34%.
Fair
Imperative
(R12.2) Supplemental folate, given alone or in combination with B6 and B12, may or may not be beneficial. If a patient with CVD is taking supplemental B vitamins to lower homocysteine, then dietetics professionals may decide to discuss the evidence for supplemental B vitamin and CVD events. Research has shown that after six months to two years, supplemental folate and B-vitamins did not reduce the risk for coronary events. Consultation with the patient's physician is warranted.
Weak
Conditional
Recommendations were based on evidence conclusion statements with Grade II
Recommendation 13. Coenzyme Q10 and Disorders of Lipid Metabolism
(R13.1) If a patient is taking coenzyme Q10 supplements, then the practitioner may discuss the lack of evidence for the association of Q10 and CHD events. Research is inconclusive regarding the relationship between co-Q10 and risk of disease.
Insufficient Evidence
Conditional
Recommendation was based on evidence conclusion statements with Grade III
Recommendation 14. Physical Activity and Lipid Metabolism Disorders and CHD
(R14.1) Moderate intensity physical activity (e.g., brisk walking, swimming laps, bicycling) should be incorporated for at least 30 minutes most, if not all, days of the week, if not contraindicated. Many individuals will have to start slowly and increase gradually to achieve goals. Moderately intense physical activity reduces the risk of CVD events, decreases LDL-C and triglycerides, and increases HDL-C.
Strong
Imperative
Recommendations were based on evidence conclusion statements with Grade II
Recommendation 15. Disorders of Lipid Metabolism and Hypertension
(R15.1) A cardioprotective dietary pattern should be planned to include 9 to 12 servings of fruits and vegetables, 2 to 3 servings of low-fat dairy products, <2.3 g sodium, weight loss if necessary, and increased physical activity (moderate intensity 3 times per week) if individuals also need to lower their blood pressure. Following this type of lifestyle change has been demonstrated to lower systolic blood pressure by at least 4 to 12 mmHg.
Strong
Imperative
Recommendation was based on evidence conclusion statements with Grade I
Recommendation 16. Disorders of Lipid Metabolism and Metabolic Syndrome
(R16.1) A calorie-controlled cardioprotective dietary pattern that avoids extremes in carbohydrate and fat intake, limits refined sugar, and includes physical activity at a moderate-intensity level for at least 30 minutes on most (preferably all) days of the week, should be used for individuals with metabolic syndrome. Weight loss of 7 to 10% of body weight should be encouraged if indicated. These lifestyle changes improve risk factors of metabolic syndrome.
Fair
Imperative
Recommendation was based on evidence conclusion statements with Grade II
Definitions:
Ratings of the Strength of the Recommendations
Strong
A Strong recommendation means that the workgroup believes that the benefits of the recommended approach clearly exceed the harms (or that the harms clearly exceed the benefits in the case of a strong negative recommendation), and that the quality of the supporting evidence is excellent/good (grade I or II). In some clearly identified circumstances, strong recommendations may be made based on lesser evidence when high-quality evidence is impossible to obtain and the anticipated benefits strongly outweigh the harms.
Fair
A Fair recommendation means that the workgroup believes that the benefits exceed the harms (or that the harms clearly exceed the benefits in the case of a negative recommendation), but the quality of evidence is not as strong (grade II or III). In some clearly identified circumstances, recommendations may be made based on lesser evidence when high-quality evidence is impossible to obtain and the anticipated benefits outweigh the harms.
Weak
A Weak recommendation means that the quality of evidence that exists is suspect or that well-done studies (grade I, II, or III) show little clear advantage to one approach versus another.
Consensus
A Consensus recommendation means that Expert opinion (grade IV) supports the guideline recommendation even though the available scientific evidence did not present consistent results, or controlled trials were lacking.
Insufficient Evidence
An Insufficient Evidence recommendation means that there is both a lack of pertinent evidence (grade V) and/or an unclear balance between benefits and harms.
Grading of Evidence Conclusion Statements
- Good/Strong
- Studies of strong design for question; free from design flaws, bias and execution problems.
- Findings generally consistent in direction and size of effect or degree of association, and statistical significance with minor exceptions at most.
- One to several good quality studies; large number of subjects studied. Studies with negative results have sufficiently large sample size for adequate statistical power.
- Studied outcome relates directly to the question. Size of effect is clinically meaningful. Significant (statistical) difference is large.
- Studied population, intervention and outcomes are free from serious doubts about generalizability.
- Fair
- Studies of strong design for question with minor methodological concerns OR only studies of weaker study design for question.
- Inconsistency among results of studies with strong design OR consistency with minor exceptions across studies of weaker design.
- Several studies by independent investigators. Doubts about adequacy of sample size to avoid Type I and Type II error
- Some doubt about the statistical or clinical significance of the effect
- Minor doubts about generalizability
- Limited/Weak
- Studies of weak design for answering the question OR inconclusive findings due to design flaws, bias or execution problems.
- Unexplained inconsistency among results from different studies OR single study unconfirmed by other studies.
- Limited number of studies; low number of subjects studied and/or inadequate sample size within studies.
- Studied outcome is an intermediate outcome or surrogate for the true outcome of interest OR size of effect is small or lacks statistical and/or clinical significance.
- Serious doubts about generalizability due to narrow or different study population, intervention or outcomes studied.
- Expert Opinion Only
- No studies available; conclusion based on usual practice, expert consensus, clinical experience, opinion, or extrapolation from basic research.
- Conclusion supported solely by statements of informed nutrition or medical commentators.
- Unsubstantiated by published research studies
- Objective data unavailable
- Generalizability limited to scope of experience.
- V Grade Not Assignable
- No evidence that pertains to question being addressed
- Relevant studies have not been done.
- Indicates area for future research.
Statement Labels (Conditional versus Imperative)
Conditional statements clearly define a specific situation, while imperative statements are broadly applicable to the target population without restraints on their pertinence. A conditional recommendation can be stated in if/then terminology, with the condition of application listed.
