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."
Diabetes Mellitus (DM): Medical Nutrition Therapy (MNT)
DM: MNT and Number/Length of Initial Series of Encounters
MNT provided by a registered dietitian (RD) is recommended for individuals with type 1 and type 2 diabetes. An initial series of three to four encounters each lasting from 45 to 90 minutes is recommended. This series, beginning at diagnosis of diabetes or at first referral to an RD for MNT for diabetes, should be completed within three to six months. The RD should determine if additional MNT encounters are needed after the initial series based on the nutrition assessment of learning needs and progress towards desired outcomes. Studies based on a range in the number (1 to 5 individual sessions or a series of 6 to 12 group sessions) and length (45 to 90 minutes) report sustained positive outcomes at one year and longer. Studies implementing a variety of nutrition interventions report a reduction in A1C levels, and some studies also report improved lipid profiles, improved weight management, adjustments in medications, and reduction in the risk for onset and progression of comorbidities.
Strong, Imperative
DM: MNT Long-Term Follow-up Encounters
At least one follow-up encounter is recommended annually to reinforce lifestyle changes and to evaluate and monitor outcomes that impact the need for changes in MNT or medication. The RD should determine if additional MNT encounters are needed. Studies involving regular lifestyle intervention sessions (up to 1 per month) report sustained positive outcomes at one year and longer.
Strong, Imperative
Recommendations Strength Rationale
- Conclusion statement was Grade I
DM: Assessment and Diabetes
DM: Nutrition Assessment
The RD should assess food intake (focusing on carbohydrate), medication, metabolic control (glycemia, lipids, and blood pressure), anthropometric measurements and physical activity to serve as the basis for implementation of the nutrition prescription, goals and intervention. Individuals who have diabetes should receive MNT tailored by the RD.
Strong, Imperative
Recommendations Strength Rationale
- Conclusion statement was Grade I
DM: Assessment of Glycemic Control
Assessment of Glycemic Control
The RD should assess glycemic control and focus medical nutrition therapy to achieve and maintain blood glucose levels in the target range (target glucose levels noted in the American Diabetes Association Standards of Medical Care in Diabetes). Studies evaluating the effectiveness of diabetes MNT at three to six months reported reductions in A1C ranging from 0.25% to 2.9%.
Strong, Imperative
Recommendation Strength Rationale
- Conclusion statement was Grade I
DM: Assess Relative Importance of Weight Management
Assess Relative Importance of Weight Management
The RD should assess the relative importance of weight management for persons with diabetes who are overweight or obese. While modest weight loss has been shown to improve insulin resistance in overweight and obese insulin-resistant individuals, research on sustained weight loss interventions lasting 1 year or longer reported inconsistent effects on A1C.
Strong, Conditional
Recommendation Strength Rationale
- Conclusion statement was Grade II
DM: Intervention Options
Intervention Options
The RD should implement MNT selecting from a variety of interventions (reduced energy and fat intake, carbohydrate counting, simplified meal plans, healthy food choices, individualized meal planning strategies, exchange lists, insulin-to-carbohydrate ratios, physical activity and behavioral strategies). Nutrition education and counseling should be sensitive to the personal needs, willingness to change, and ability to make changes of the individual with diabetes. Studies reporting on effectiveness of MNT report a variety in the number and type of MNT sessions that lead to improved outcomes.
Strong, Imperative
Recommendation Strength Rationale
- Conclusion statement was Grade I
DM: Macronutrients
Macronutrient Percentages
The RD should encourage consumption of macronutrients based on the Dietary Reference Intakes (DRI) for healthy adults. Research does not support any ideal percentage of energy from macronutrients for persons with diabetes.
Strong, Imperative
Recommendation Strength Rationale
- Conclusion statement for Carbohydrate was Grade I
- Conclusion statement for Protein was Grade II
DM: Carbohydrate
DM: Carbohydrate Intake Consistency
In persons on either MNT alone, glucose-lowering medications or fixed insulin doses, meal and snack carbohydrate intake should be kept consistent on a day-to-day basis. Consistency in carbohydrate intake results in improved glycemic control.
Strong, Conditional
Carbohydrate Intake and Insulin Dose Adjustment
In persons with type 1 or type 2 diabetes who adjust their mealtime insulin doses or who are on insulin pump therapy, insulin doses should be adjusted to match carbohydrate intake (insulin-to-carbohydrate ratio). This can be accomplished by comprehensive nutrition education and counseling on interpretation of blood glucose patterns, nutrition-related medication management and collaboration with the healthcare team. Adjusting insulin dose based on planned carbohydrate intake improves glycemic control and quality of life without any adverse effects.
Strong, Conditional
Recommendation Strength Rationale
- Conclusion statement was Grade I
DM: Sucrose and Diabetes
DM: Sucrose Intake
If persons with diabetes choose to eat foods containing sucrose, the sucrose-containing foods should be substituted for other carbohydrate foods. Sucrose intakes of 10 to 35 percent of total energy intake do not have a negative effect on glycemic or lipid responses when substituted for isocaloric amounts of starch.
Strong, Conditional
Recommendation Strength Rationale
- Conclusion statement was Grade I
DM: Non-nutritive Sweeteners and Diabetes
DM: Non-nutritive Sweeteners
If persons with diabetes choose to consume products containing U.S. Food and Drug Administration (FDA)-approved non-nutritive sweeteners, at levels that do not exceed the acceptable daily intakes (ADIs), the RD should advise that some of these products may contain energy and carbohydrate from other sources that needs to be accounted for. Research on non-nutritive sweeteners reports no effect on changes in glycemic response.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statements were Grade III
DM: Glycemic Index and Diabetes
DM: Glycemic Index
If the use of glycemic index (GI) is proposed as a method of meal planning, the RD should advise on the conflicting evidence of effectiveness of this strategy. Studies comparing high versus low GI diets report mixed effects on A1C.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statement was Grade II
DM: Fiber and Diabetes
DM: Fiber Intake and Glycemia
Recommendations for fiber intake for people with diabetes are similar to the recommendations for the general public (daily reference intake [DRI]: 14 grams per 1000 kilocalories [kcal]). While diets containing 44 to 50 grams of fiber daily are reported to improve glycemia, more usual fiber intakes (up to 24 grams daily) have not shown beneficial effects on glycemia. It is unknown if free-living individuals can daily consume the amount of fiber needed to improve glycemia.
Strong, Imperative
DM: Fiber Intake and Cholesterol
Include foods containing 25 to 30 grams of fiber per day, with special emphasis on soluble fiber sources (7 to 13 grams). Diets high in total and soluble fiber, as part of cardioprotective nutrition therapy, can further reduce total cholesterol by 2% to 3% and low-density lipoprotein (LDL) cholesterol up to 7%.
Strong, Imperative
Recommendation Strength Rationale
- Conclusion statement for Fiber and Diabetes was Grade I
- Conclusion statement for Fiber and Coronary Heart Disease (CHD) were Grades I, II, and III
DM: Protein and Diabetes
DM: Protein Intake and Normal Renal Function
In persons with type 1 or type 2 diabetes with normal renal function, the RD should advise that usual protein intake of approximately 15% to 20% of daily energy intake does not need to be changed. Although protein has an acute effect on insulin secretion, usual protein intake in long-term studies has minimal effects on glucose, lipids, and insulin concentrations.
Fair, Conditional
Protein Intake and Nephropathy
In persons with diabetic nephropathy, a protein intake of one gram or less per kg body weight per day is recommended. Diets with less than one gram protein per kg body weight per day have been shown to improve albuminuria in persons with nephropathy; however, they have not been shown to have significant effects on glomerular filtration rates (GFR).
Fair, Conditional
DM: Protein Intake and Late Stage Nephropathy
For persons with late stage diabetic nephropathy (Chronic Kidney Disease [CKD] Stages 3-5), hypoalbuminemia (an indicator of malnutrition) and energy intake must be monitored and changes in protein and energy intake made to correct deficits. A protein intake of approximately 0.7 grams per kg body weight per day has been associated with hypoalbuminemia, whereas a protein intake of approximately 0.9 grams per kg body weight per day has not.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statement is Grade II
DM: Glucose Monitoring
DM: Blood Glucose Monitoring
For individuals on nutrition therapy alone or nutrition therapy in combination with glucose-lowering medications, self-monitoring of blood glucose (SMBG) is recommended. Frequency and timing is dependent on diabetes management goals and therapies (i.e., MNT, diabetes medications and physical activity). When SMBG is incorporated into diabetes education programs and the information from SMBG is used to make changes in diabetes management, SMBG is associated with improved glycemic control.
Fair, Conditional
DM: Frequency of Blood Glucose Monitoring
For persons with type 1 or type 2 diabetes on insulin therapy, at least three to eight blood glucose tests per day are recommended to determine the adequacy of the insulin dose(s) and guide adjustments in insulin dose(s), food intake and physical activity. Some insulin regimens require more testing to establish the best integrated therapy (insulin, food, and activity). Once established, some insulin regimens will require less frequent self-monitoring of blood glucose (SMBG). Intervention studies that include self-management training and adjustment of insulin doses based on SMBG result in improved glycemic control.
Strong, Conditional
DM: Possible Need for Continuous Glucose Monitoring or More Frequent SMBG
Persons experiencing unexplained elevations in A1C or unexplained hypoglycemia and hyperglycemia may benefit from use of continuous glucose monitoring (CGM) or more frequent SMBG. It is essential that persons with diabetes receive education as to how to calibrate CGM and how to interpret CGM results. Studies have proven the accuracy of CGM and most show that using the trend/pattern data from CGM can result in less glucose variability and improved glucose control.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statements were Grades I and II
DM: Prevention and Treatment of CVD
DM: CVD and Cardioprotective Nutrition Therapy
Cardioprotective nutrition interventions for the prevention and treatment of CVD should be implemented in the initial series of encounters. Diabetes is associated with an increased risk for CVD and glycemic control may improve the lipid profile.
Strong, Imperative
CVD and Cardioprotective Nutrition Interventions
Cardioprotective nutrition interventions for prevention and treatment of CVD include reduction in saturated and trans fats and dietary cholesterol, and interventions to improve blood pressure. Studies in persons with diabetes utilizing these interventions report a reduction in cardiovascular risk and improved cardiovascular outcomes.
Strong, Imperative
Recommendation Strength Rationale
- Conclusion statement was Grade I
DM: Weight Management
DM: Diabetes and Weight Management
The RD should advise that glycemic control is the primary focus for diabetes management. While decreasing energy intake may improve glycemic control, it is unclear whether weight loss alone will improve glycemic control. Sustained weight loss interventions lasting 1 year or longer reported inconsistent effects on hemoglobin A1C.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statement was Grade II
DM: Physical Activity
DM: Type 2 Diabetes and Physical Activity
In persons with type 2 diabetes, 90 to 150 minutes of accumulated moderate-intensity aerobic physical activity per week as well as resistance/strength training three times per week is recommended. Both aerobic and resistance training improve glycemic control, independent of weight loss. Physical activity also improves insulin sensitivity and decreases risk for cardiovascular disease and all-cause mortality.
Strong, Conditional
DM: Type 1 Diabetes and Physical Activity
Individuals with type 1 diabetes should be encouraged to engage in regular physical activity. Although exercise is not reported to improve glycemic control in persons with type 1 diabetes, individuals may receive the same benefits from exercise as the general public—decreased risk for cardiovascular disease and improved sense of well-being.
Fair, Conditional
DM: Physical Activity and Insulin/Insulin Secretagogue Use
The RD should instruct individuals on insulin or insulin secretagogues on the safety guidelines to prevent hypoglycemia (frequent blood glucose monitoring and possible adjustment in insulin dose or carbohydrate intake). Research indicates that the incidence of hypoglycemia during exercise may depend on baseline glucose levels.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statements were Grades I and II
DM: Coordination of Care and Diabetes
DM: Coordination of Care
The RD should implement MNT and coordinate care with an interdisciplinary team. An interdisciplinary team approach is necessary to integrate MNT for patients with diabetes into overall management.
Consensus, Imperative
Recommendation Strength Rationale
- Conclusion statement was Grade I
DM: Monitor & Evaluate and Diabetes
DM: Monitoring and Evaluation
The RD should monitor and evaluate food intake, medication, metabolic control (glycemia, lipids, and blood pressure), anthropometric measurements and physical activity. Research reports sustained improvements in A1C at 12 months and longer with long-term follow-up encounters with an RD.
Strong, Imperative
DM: Evaluation of Glycemic Control
The RD should primarily use blood glucose monitoring results in evaluating the achievement of goals and effectiveness of MNT. Glucose monitoring results can be used to determine whether adjustments in foods and meals will be sufficient to achieve blood glucose goals or if medication additions or adjustments need to be combined with MNT.
Consensus, Imperative
Recommendation Strength Rationale
- Conclusion statement for MNT was Grade I
Definitions:
Conditional versus Imperative Recommendations
Recommendations can be worded as conditional or imperative statements. Conditional statements clearly define a specific situation, while imperative statements are broadly applicable to the target population without restraints on their pertinence. More specifically, a conditional recommendation can be stated in if/then terminology (e.g., If an individual does not eat food sources of omega-3 fatty acids, then 1g of EPA and DHA omega-3 fatty acid supplements may be recommended for secondary prevention).
In contrast, imperative recommendations "require," or "must," or "should achieve certain goals," but do not contain conditional text that would limit their applicability to specified circumstances. (e.g., Portion control should be included as part of a comprehensive weight management program. Portion control at meals and snacks results in reduced energy intake and weight loss).
Levels of Evidence
| Strength of Evidence Elements |
Grade I
Good/Strong
|
Grade II
Fair
|
Grade III
Limited/Weak
|
Grade IV
Expert Opinion Only
|
Grade V
Grade Not Assignable
|
Quality
- Scientific rigor/validity
- Considers design and execution
|
Studies of strong design for question
Free from design flaws, bias and execution problems
|
Studies of strong design for question with minor methodological concerns
OR
Only studies of weaker study design for question
|
Studies of weak design for answering the question
OR
Inconclusive findings due to design flaws, bias or execution problems
|
No studies available
Conclusion based on usual practice, expert consensus, clinical experience, opinion, or extrapolation from basic research
|
No evidence that pertains to question being addressed |
Consistency
Of findings across studies
|
Findings generally consistent in direction and size of effect or degree of association, and statistical significance with minor exceptions at most |
Inconsistency among results of studies with strong design
OR
Consistency with minor exceptions across studies of weaker designs
|
Unexplained inconsistency among results from different studies
OR
Single study unconfirmed by other studies
|
Conclusion supported solely by statements of informed nutrition or medical commentators |
NA |
Quantity
- Number of studies
- Number of subjects in studies
|
One to several good quality studies
Large number of subjects studies
Studies with negative results having sufficiently large sample size for adequate statistical power
|
Several studies by independent investigators
Doubts about adequacy of sample size to avoid Type I and Type II error
|
Limited number of studies
Low number of subjects studies and/or inadequate sample size within studies
|
Unsubstantiated by published studies |
Relevant studies have not been done |
Clinical Impact
- Importance of studies outcomes
- Magnitude of effect
|
Studied outcome relates directly to the question
Size of effect is clinically meaningful
Significant (statistical) difference is large
|
Some doubt about the statistical or clinical significance of effect |
Studies 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
|
Objective data unavailable |
Indicates area for future research |
Generalizability
To population of interest
|
Studied population, intervention and outcomes are free from serious doubts about generalizability |
Minor doubts about generalizability |
Serious doubts about generalizability due to narrow or different study population, intervention or outcomes studied |
Generalizability limited to scope of experience |
NA |
This grading system was based on the grading system from: Greer N, Mosser G, Logan G, Wagstrom Halaas G. A practical approach to evidence grading. Jt Comm. J Qual Improv. 2000; 26:700-712. In September 2004, The ADA Research Committee modified the grading system to this current version.
Criteria for Recommendation Rating
| Statement Rating |
Definition |
Implication for Practice |
| 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. |
Practitioners should follow a Strong recommendation unless a clear and compelling rationale for an alternative approach is present. |
| 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. |
Practitioners should generally follow a Fair recommendation but remain alert to new information and be sensitive to patient preferences. |
| 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. |
Practitioners should be cautious in deciding whether to follow a recommendation classified as Weak, and should exercise judgment and be alert to emerging publications that report evidence. Patient preference should have a substantial influencing role. |
| 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. |
Practitioners should be flexible in deciding whether to follow a recommendation classified Consensus, although they may set boundaries on alternatives. Patient preference should have a substantial influencing role. |
| 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. |
Practitioners should feel little constraint in deciding whether to follow a recommendation labeled as Insufficient Evidence and should exercise judgment and be alert to emerging publications that report evidence that clarifies the balance of benefit versus harm. Patient preference should have a substantial influencing role. |
*Conclusion statements are assigned a grade based on the strength of the evidence. Grade I is good; grade II, fair; grade III, limited; grade IV signifies expert opinion only and grade V indicates that a grade is not assignable because there is no evidence to support or refute the conclusion. The evidence and these grades are considered when assigning a rating (Strong, Fair, Weak, Consensus, Insufficient Evidence - see chart above) to a recommendation.
Adapted by the American Dietetic Association from the American Academy of Pediatrics, Classifying Recommendations for Clinical Practice Guideline, Pediatrics. 2004;114;874-877.
