July 2019 Issue
Diabetes Management & Nutrition Guide: ADA’s 2019 Nutrition Therapy Consensus Report
By Hope Warshaw, MMSc, RD, CDE, BC-ADM, FAADE
Today’s Dietitian
Vol. 21, No. 7, P. 36
An Overview of What’s New in Nutrition Guidance for People With Diabetes and Prediabetes
The American Diabetes Association (ADA) recently released “Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report,” referred to here as the Consensus Report or report, an in-depth update to its 2014 nutrition therapy recommendations.1,2
Today’s Dietitian (TD) digs into the details on what’s new from an inside perspective from three dietitians who are certified diabetes educators (CDEs) and members of the ADA writing committee, including the ADA’s staff liaison. TD also gleans an outside perspective from two seasoned dietitians who are CDEs and who reviewed the report for this article.
Background
Roughly every five years over the last several decades, the ADA has appointed a writing group to research and develop its position statement on nutrition guidance. The ADA has evolved its processes for developing positions on diabetes-related care, which has impacted the Consensus Report in several ways. “As of 2018, the ADA no longer publishes individual position statements on diabetes-related care,” says Sacha Uelmen, RDN, CDE, managing director for diabetes education and nutrition at the ADA, lead staff liaison to the Consensus Report writing group, and coauthor of the report. “The association continues to publish its Standards of Care, which are developed and/or reviewed by experts and ADA’s Professional Practice Committee. They’re published online with open access and as a printed supplement in Diabetes Care each January.” The ADA recently implemented a system to immediately update existing Standards of Care as Living Standards.3 The Living Standards update with content on the Consensus Report occurred simultaneously with its release. The update will be integrated into the 2020 Standards of Care and will shape all ADA nutrition content and materials.
The Consensus Report covers guidance for nonhospitalized adults with prediabetes as well as type 1 and type 2 diabetes. Prediabetes wasn’t covered in previous reports but was included in this iteration due to the current importance of diabetes prevention, according to Uelmen. Guidance for pediatric populations and gestational diabetes wasn’t within the scope of this report.
Consensus Report Methodology
Significant effort went into compiling the Consensus Report. The writing group included a panel of 14 distinguished professionals with diverse scientific, clinical, and nutrition expertise such as RDs, CDEs, endocrinologists, a primary care physician, and a patient advocate. With the 2014 position statement1 as a starting point, the panel completed review of more than 600 publications published from early 2014 through early 2018 with assistance from an outside market research company paid for with ADA funds.2 “It was a very big task. Writing group members donated hundreds of hours,” says Alison Evert, MS, RD, CDE, manager of nutrition and diabetes programs at the University of Washington Neighborhood Clinics and cochair of the writing group.
Though this literature review was extensive, “it’s disappointing to observe that nutrition research continues to lag behind other areas of diabetes research, such as pharmaceutical trials that can include several thousand participants in years-long studies at multiple sites around the world,” Evert says. She adds that it’s not uncommon for nutrition intervention trials investigating different eating patterns to include only 100 participants and be of short durations (eg, 12 to 24 weeks).
Uelmen notes that she was surprised at “the number of unanswered questions we still have, despite a very large volume of research in diabetes nutrition.”
Nutrition Guidance Common Denominators
In its 15 pages of dense content and nearly 350 references, the Consensus Report underscores several essential recommendations relevant to all adults with diabetes and prediabetes.2
• For optimal, long-term implementation and adherence to a healthful eating pattern to achieve optimal outcomes, individualization must be a cornerstone of therapy.
- There’s no ideal percentage of calories from carbohydrate, protein, and fat for everyone. A variety of eating patterns is acceptable.
- There isn’t one single recommended nutrition plan for everyone, given the broad spectrum of this population. Many food choices and eating patterns can help people achieve health goals and quality of life.
• There’s consensus that health care providers should focus on key factors that are common among the healthful eating patterns. Mary Lou Perry, MS, RDN, CDE, a dietitian specialist at the University of Virginia Heart and Vascular Center, was asked to review the Consensus Report for this article. She refers to these key factors as “eating pattern common denominators”:
- Emphasize consumption of nonstarchy vegetables.
- Minimize consumption of added sugars and refined grains.
- Choose whole foods over highly processed foods.
- Replace sugar-sweetened beverages with water as often as possible.
Cliffs Notes on Hot Topics
The Consensus Report covers a myriad of topics. What follows are several of the most important ones as well as commentary from the five RDs interviewed for this article.
Effectiveness of MNT and Diabetes Self-Management Education and Support
People with diabetes who are Medicare beneficiaries and many others with private health plan coverage are eligible for MNT and Diabetes Self-Management Education and Support (DSMES) services. However, it’s documented in this report and others that these services are woefully underutilized despite strong evidence supporting their clinical efficacy and cost-effectiveness.4,5 “Research continues to indicate MNT for adults with type 2 diabetes can result in A1c reductions similar to or greater than those seen with some currently available glucose-lowering medications,” Evert says. She implores RDs to more proactively share the effectiveness of their services with the health care community. MNT and DSMES should be implemented in accordance with the education algorithm in the Joint Statement.4 The unique expertise and training of the RD as the preferred team member to deliver MNT is discussed, but the point is made that all members of the health care team should champion the benefits of nutrition therapy and key nutrition messages.
Gamut of Eating Patterns
Another important topic involves eating patterns. People don’t eat nutrients. They eat combinations of different foods that establish their eating patterns. The Consensus Report dissects the current literature on the gamut of eating patterns for people with diabetes. Patti Urbanski, MEd, RD, LD, CDE, diabetes educator and clinical dietitian at St. Luke’s Diabetes Care Program in Duluth, Minnesota, and a writing group member charged with delving into this literature, casts light on this research. “In reality, we have very few eating pattern studies that compare different eating patterns head to head, such as Mediterranean vs very low carbohydrate. Most eating plan studies compare the study diet to a moderate-carbohydrate, low-fat eating plan.”
An extensive table that occupies an entire page of the report describes each eating pattern and details its research-based clinical benefits. The patterns range from vegetarian or vegan to Mediterranean, to low carbohydrate (defined as 26% to 45% of total calories), to very low carbohydrate (defined as <26% of calories). Perry calls this table, Table 3, “one of her favorite features of the report,” noting she plans to use it as a shared decision-making tool with people she counsels. She’ll share options and discuss the benefits in concert with their current and desired eating patterns at that point in time.
“If RDs read the Consensus Report and think ‘boy, they really missed some important research,’ it’s probably because research on that eating pattern did not include people with diabetes, or was not a well-conducted or controlled trial. Only studies that included people with diabetes or prediabetes were included,” Urbanski says.
Low- and Very Low-Carbohydrate Eating Patterns
Significant controversy exists regarding the amount of carbohydrate people with diabetes should consume, and whether low- and even very low-carbohydrate eating patterns are beneficial. Considering the common denominators mentioned earlier, the Consensus Report recommends that reducing overall carbohydrate intake to achieve a low-carbohydrate eating pattern has demonstrated the most evidence for improving glycemia (lowering glucose and A1c levels). The report recommends very low-carbohydrate eating patterns for select people with type 2 diabetes who aren’t meeting glycemic targets or for whom reducing their glucose-lowering medications is a priority. Three caveats to consider with this eating plan mentioned in the report: the long-term impact on glycemia, CVD risk factors or clinical events, and long-term adherence.
This topic elicited input from both RDs involved with writing the report and those offering outsider perspectives. Urbanski, who has had type 1 diabetes for 40 years, says, “It’s time for RDs to talk to people about low- and very low-carbohydrate diets. We need to help people think about the healthiest way to follow these eating plans. If we aren’t willing to help people follow these eating plans in the healthiest way possible, someone else is sure to sell them a book or diet supplement.” The author wrote an article in the November 2018 issue of TD offering clinical practice pointers concerning very low-carbohydrate diets for people with type 2 diabetes.6
Suzanne Weldon, RD, LD, CDE, from the Diabetes and Thyroid Center of Fort Worth in Fort Worth, Texas, who’s had type 1 diabetes for 32 years, concurs: “We need to be open to people using these eating patterns. However, we also need to consistently assess and monitor their nutritional status and need for adjustments in their glucose-lowering medications, especially ones that can cause hypoglycemia.”
Uelmen casts another light on this topic. “I was surprised to learn that the low-carbohydrate eating patterns studied were not as low in carbohydrate as one would think with all of the media attention around avoiding carbohydrates.”
Urbanski raises a critical point. “We always have to remember that research in people with type 2 diabetes cannot be automatically translated to type 1 diabetes. They’re two very different disorders.” In fact, Urbanski notes, we have very limited data on low-carbohydrate diets and type 1 diabetes, but she predicts this will change in the next few years.
Dietary Fiber
In addition to offering recommendations on a variety of eating patterns, the Consensus Report provides guidance on dietary fiber in sync with the 2015–2020 Dietary Guidelines for Americans.7 Due to fiber’s multiple health benefits, people should consume a minimum of 14 g per 1,000 kcal per day. It’s noted, however, that glycemic lowering is achieved with fiber consumption only in excess of 50 g per day, a concept often lost in simplified messages to the public. A notation mentions that at least one-half of grain consumption should be from whole intact grains, advice that may run counter to how some people follow low- or very low-carbohydrate eating plans. Food choices to achieve a sufficient and varied fiber intake can be particularly challenging if a goal is to limit carbohydrate consumption. As Urbanski asserts, the assistance of RDs in this effort is critical.
Glycemic Index (GI) and Glycemic Load (GL)
This topic has been debated for years under the umbrella of carbohydrate consumption. The Consensus Report cites two systematic literature reviews on people at risk of and with diabetes and reports that GI and GL have no significant impact on A1c and have mixed results on fasting glucose. Uncertainty remains in the clinical utility of GI and GL.
Intermittent Fasting
Due to the increased interest in intermittent fasting, the writing group reviewed the literature specific to diabetes and type 2 diabetes prevention. Three studies showed that intermittent fasting, either in consecutive days of restriction or by fasting 16 hours per day or more, may result in weight loss but didn’t improve A1c compared with a nonfasting eating plan. The report calls for more research.
Counseling Adults With Type 2 and Limited Literacy and/or Numeracy
To counsel adults with type 2 diabetes who don’t take insulin and who have limited health literacy or numeracy or those who are older and prone to hypoglycemia, the Consensus Report suggests advocating the basic principles of healthful eating and appropriate portion sizes as an effective strategy to achieve glycemic control and weight management.
Fat Consumption and CVD
The Consensus Report also reviews the current literature on dietary fats and their impact on cardiovascular health in people with diabetes. “Conversations about what to eat often zero in on glycemic management and the impact of carbohydrates, leaving the critical topic of fat and cardiovascular health overlooked,” Evert says. Yet, we know that CVD causes significant morbidity and mortality in people with diabetes, and hypertension is an underlying cause of microvascular complications. Control of lipids and hypertension is paramount to positive clinical outcomes. Key messages on fats remain consistent.1,2 Replacing saturated fat with unsaturated fat reduces total and LDL cholesterol and lowers CVD risk. Counseling people with type 2 diabetes to replace foods high in carbohydrate with foods higher in healthful fats can improve glycemia and lipids.
“However, despite considerable literature on this topic, we still have a lot of questions about fat recommendations to prevent CVD and type 2 diabetes,” Urbanski says. “We know even less about optimal fat intake in type 1 diabetes.”
RD’s Role in Glucose-Lowering Medication Management
A brief yet important addition to this report is a discussion on the RD’s role in adjusting glucose-lowering medications. Evert calls attention to the extreme challenge of therapeutic inertia in diabetes management today and points to the role RDs can play within their scopes of practice to implement organization-approved medication adjustment protocols.8
Perry agrees: “Due to this brief mention, I think we’ll see more RDs using these protocols.”
With regard to insulin dosing, there’s consensus that the amount of fat and protein in a meal can impact the level and timing of postprandial glycemic excursions. For this reason, when people who take insulin consume a mixed meal that contains carbohydrate and is high in fat and/or protein, they should consider the amount of carbohydrate as well as protein and fat when dosing insulin. RDs working with people who take insulin should help them learn to assess their fat and protein consumption in addition to carbohydrate intake. Insulin-dosing decision-making should be based on macronutrient intake and the results of their self-monitoring of blood glucose and/or continuous glucose monitoring results.
The Encompassing Topic of Weight Management
The Consensus Report also explores weight management (including weight loss and weight loss maintenance) comprehensively in the following areas:
• Prediabetes: People diagnosed with prediabetes should be referred to an intensive behavioral lifestyle intervention program modeled after the year-long National Diabetes Prevention Program, which is covered by Medicare.9 To prevent or delay the progression to type 2 diabetes, the program should improve eating habits, increase moderate-intensity physical activity to at least 150 minutes per week, and achieve and maintain a 7% to 10% loss of initial body weight, if needed.
• Remission of prediabetes and type 2 diabetes: Complete remission is defined in the Consensus Report as maintenance of euglycemia without glucose-lowering medications for at least one year. The Consensus Report supports what RDs already know: Successful weight loss and maintenance results from 1) a customized plan; 2) regular and sufficient physical activity; and 3) learning and using behavior change strategies. The most surprising detail in this report and one flagged by Weldon and Perry is that while we’ve been hearing that a 5% to 7% weight loss achieves myriad health benefits including glucose lowering, two important studies, the Look AHEAD trial10 and DiRECT (Diabetes Remission Clinical Trial),11 show that weight loss and maintenance of 15% or greater results in better health outcomes. RDs should review the two-year results from DiRECT published after release of the Consensus Report.11 As Weldon aptly summarizes, “A small amount of weight loss goes a long way to improve health outcomes. Our job is to help people set reasonable and attainable weight loss goals and focus more on keeping those lost pounds off.”
• Metabolic surgery: The use of metabolic surgery or weight management medications should be considered in conjunction with an overall healthful eating plan for select individuals.
• Eating disorders: The prevention, diagnosis, and treatment of eating disorders and disordered eating must be top of mind when clinicians counsel those with diabetes or prediabetes about weight management.
• Type 1 diabetes: While type 1 diabetes has been synonymous with being lean, that’s no longer the case. Reports now show that more than 50% of people with type 1 diabetes have overweight or obesity. The Consensus Report recommends weight management as an essential component of type 1 diabetes care today.
Consider this article as simply scratching the surface of the Consensus Report and as an invitation to read the report in full along with the accompanying commentary about where the consensus and uncertainties are in prevention and management of diabetes by Wylie-Rosett and Hu.12 “I urge RDs to read this report thoroughly. It provides a succinct yet accessible overview of the state of nutrition and diabetes research to better support how we implement recommendations into practice. It supports the person-centered care and counseling we’re trained to do as RDs,” Uelmen says.
“This will now be my go-to document from which to make recommendations,” Perry says. “It’s easy to read, provides clear ‘consensus recommendations’ and uses a Q&A style to answer common questions.”
Evert summons a call to action for RDs: “With increasing numbers of people with diabetes, a majority [of] whom are cared for by primary care providers, we need as many qualified care providers as possible to assist people with or at risk of diabetes to achieve their personal health goals and control of glucose, lipids, and hypertension.”
— Hope Warshaw, MMSc, RD, CDE, BC-ADM, FAADE, is owner of Hope Warshaw Associates, LLC, a diabetes and nutrition focused consultancy based in Asheville, North Carolina. She’s the author of numerous books published by the American Diabetes Association, including Diabetes Meal Planning Made Easy and Eat Out, Eat Well: The Guide to Eating Healthy in Any Restaurant. Warshaw served as the 2016 president of AADE and currently serves on the board of the Academy of Nutrition and Dietetics Foundation.
[Sidebar]
OTHER TAKE-AWAYS FROM THE REPORT
• Vitamin and mineral supplements: In absence of an underlying deficiency, evidence doesn’t support their use.
• Vitamin B12 and metformin use: Assess for vitamin B12 status annually and advise on B12 supplementation if deficiency is found.
• Sodium reduction: Limiting sodium intake to no more than 2,300 mg/day has beneficial effects on blood pressure. Further reduction warrants caution.
• Personalized nutrition: Approaches to explore genetic, metabolomic, and microbiome variations to date haven’t demonstrated consistent outcomes in type 1 or type 2 diabetes or prediabetes.
— HW
References
1. Evert AB, Boucher JL, Cypress M, et al. Nutrition therapy recommendations for the management of adults with diabetes. Diabetes Care. 2014;37(Suppl 1):S120-S143.
2. Evert AB, Dennison M, Gardner CD, et al. Nutrition therapy for adults with diabetes or prediabetes: a consensus report. Diabetes Care. 2019;42(5):731-754.
3. Living standards of medical care in diabetes. American Diabetes Association website. http://care.diabetesjournals.org/living-standards. Accessed May 14, 2019.
4. Powers MA, Bardsley J, Cypress M, et al. Diabetes self-management education and support in type 2 diabetes: a joint position statement of the American Diabetes Association, the American Association of Diabetes Educators, and the Academy of Nutrition and Dietetics. Diabetes Care. 2015;38(7):1372-1382.
5. Warshaw HS. Is it time to remodel diabetes self-management education and support? Am J Manag Care. 2018;24(11 Spec No):SP449-SP451.
6. Warshaw H, Smithson T. Very low-carbohydrate diets: an evaluation of efficacy in type 2 diabetes prevention and management, and considerations for translating research to practice. Today’s Dietitian. 2018;20(11):28-32.
7. US Department of Health & Human Services. Dietary Guidelines for Americans 2015–2020: Eighth Edition. http://health.gov/dietaryguidelines/2015/. Published January 7, 2016. Accessed May 15, 2019.
8. Overcoming therapeutic inertia. American Diabetes Association website. https://professional.diabetes.org/meeting/other/overcoming-therapeutic-inertia. Accessed May 14, 2019.
9. Warshaw H. Guest commentary: type 2 diabetes prevention. Today’s Dietitian. 2018:20(8):31-32.
10. Look AHEAD Research Group. Eight-year weight losses with an intensive lifestyle intervention: the Look AHEAD study. Obesity (Silver Spring). 2014;22(1):5-13.
11. Lean MEJ, Leslie WS, Barnes AC, et al. Durability of a primary care-led weight-management intervention for remission of type 2 diabetes: 2-year results of the DiRECT open-label, cluster-randomised trial. Lancet Diabetes Endocrinol. 2019;7(5):344-355.
12. Wylie-Rosett J, Hu FB. Nutritional strategies for prevention and management of diabetes: consensus and uncertainties. Diabetes Care. 2019;42(5):727-730.