U.K. Prospective Diabetes Study Group, prepared by Manley SE, Stratton IM, Cull CA, Frighi V, Eeley A, Matthews DR, Holman RR, Turner RC, Neil HAW: Effects of three months’ diet after diagnosis of type 2 diabetes on plasma lipids and lipoproteins (UKPDS 45). Diabet Med 17:518–523, 2000
Wilson C, Brown T, Acton K, Gilliland A: Effects of clinical nutrition education and educator discipline on glycemic control outcomes in the Indian Health Service. Diabetes Care 26:2500–2504, 2003
Wolf AM, Conaway MR, Crowther JQ, Hazen KY, Nadler JL, Oneida B, Bovbjerg VE: Translating lifestyle intervention to practice in obese patients with type 2 diabetes: Improving Control with Activity and Nutrition (ICAN) study. Diabetes Care 27:1570–1576, 2004
Ziemer DC, Berkowitz KJ, Panayioto RM, El-Kebbi IM, Musey VC, Anderson LA, Wanko NX, Fowke ML, Brazier CW, Dunbar VG, Slocum W, Bacha GM, Gallina DL, Cook CB, Phillips LS: A simple meal plan emphasizing healthy food choices is as effective as an exchange-based meal plan for urban African Americans with type 2 diabetes. Diabetes Care 26:1719–1724, 2003
Joyce Green Pastors, MS, RD, CDE, is an Assistant Professor of Education, Internal Medicine, Virginia Center for Diabetes Professional Education, University of Virginia Health System, Charlottesville, VA. Marion J. Franz, MS, RD, CDE, is a Nutrition/Health Consultant at Nutrition Concepts by Franz, Inc., Minneapolis, MN.
Chapter 2 Macronutrients and Nutrition Therapy for Diabetes
Marion J. Franz, MS, RD, CDE
Macronutrient Distribution in the Nutrition Prescription
Carbohydrates and Diabetes Nutrition Therapy
Protein and Diabetes Nutrition Therapy
Dietary Fat and Diabetes Nutrition Therapy
Summary of Recommendations for Macronutrients
Highlights Macronutrients and Nutrition Therapy for Diabetes
• No ideal distribution of macronutrients—carbohydrate, protein, or fat—for a diabetes nutrition prescription has been identified. Instead, as for all Americans, a healthy eating pattern is recommended. For guidelines on healthy eating patterns, the Dietary Reference Intakes or the Dietary Guidelines for Americans, 2010, are helpful resources.
• Available evidence does not show an adverse effect on insulin sensitivity from carbohydrate intake; a higher carbohydrate intake may instead improve insulin resistance.
• Three 1-year studies in individuals with type 2 diabetes comparing higher-carbohydrate diets to lower-carbohydrate, low-fat, or high–monounsaturated fat diets found no differences in A1C, LDL cholesterol, or triglyceride levels; blood pressure; or weight at study end. Therefore, total energy intake and a healthy eating pattern should take precedence over the distribution of macronutrients.
• Sucrose-containing foods can be substituted for other carbohydrates in the food/meal plan. However, as for the general public, excessive intake of sugars should be avoided in a healthy eating pattern. Whenever possible, nutrient-dense foods containing whole grains and fiber should be selected.
• In people with type 2 diabetes, ingestion of protein does not increase postprandial glucose or lipid responses but does cause an acute insulin response. This response does not result in a long-term effect on insulin levels.
• Although it is commonly stated that fats slow absorption and delay peak glycemic responses, evidence as to the magnitude of this effect is difficult to find.
• Chronic intakes of higher total and saturated fats are associated with an increase in insulin resistance, and consumption of saturated and trans fatty acids is associated with an adverse effect on lipid/lipoprotein profile and increased risk of cardiovascular disease. It is recommended that saturated fats be replaced with unsaturated fats and intake of trans fat be minimized. Ingestion of omega-3 fatty acids from fish is recommended.
Macronutrients and Nutrition Therapy for Diabetes
Nutrition therapy implemented appropriately contributes to important and essential outcomes in the management of diabetes. However, just as there is no one medical therapy appropriate for all individuals with type 1 or type 2 diabetes, there is no one prescription for nutrition therapy appropriate for all people with diabetes. It is clear, as outlined in Chapter 1, that a variety of nutrition interventions lead to positive outcomes. What is essential is that health care professionals select nutrition therapy interventions that will lead to positive outcomes in the patients they are counseling. Agreement from diabetes patients as to their willingness and ability to implement nutrition interventions is equally essential.
Primary goals of nutrition therapy for diabetes are to improve glycemic, lipid, and blood pressure control, thus contributing to reduced risk for potential long-term complications of diabetes and heart disease, and to improve the quality of life for individuals with diabetes. How best to achieve these goals has been, and remains, controversial. Because all fields of medicine have moved toward evidence-based recommendations, so has the field of nutrition therapy and diabetes. In 2008, the Academy of Nutrition and Dietetics (Acad Nutr Diet; formerly the American Dietetic Association) published evidence-based nutrition practice guidelines (EBNPG) for adults with type 1 and type 2 diabetes in the Acad Nutr Diet Evidence Analysis Library (Acad Nutr Diet 2008). Subsequently, a review of the research leading to the EBNPG, a summary of the research published after the completion of the Evidence Analysis Library (through 1 September 2009), and evidence-based diabetes nutrition recommendations were published (Franz 2010). In 2008, the American Diabetes Association (ADA) also published a position statement titled “Nutrition Recommendations and Interventions for Diabetes” (ADA 2008). These recommendations are integrated into their annual standards of medical care in diabetes and updated as new evidence becomes available (ADA 2012).
This chapter reviews and summarizes previously published macronutrient (carbohydrate, protein, and fat) evidence, incorporates research published after 1 September 2009, and summarizes key recommendations related to the role of macronutrients in nutrition therapy for diabetes. A literature search was conducted using PubMed MEDLINE, and additional articles were identified from reference lists. Search criteria included the following: carbohydrate, protein, fat, research in human subjects with diabetes, English language articles, and publication after completion of the literature search for the Acad Nutr Diet EBNPG review. The initial search produced 58 articles, of which 42 were excluded because titles or abstracts did not meet inclusion criteria. Sixteen articles were retrieved for more detailed evaluation. Six of these articles are included and four were added from the review of reference lists, making a total of 10 studies (8 clinical trials and 2 observational studies) that met inclusion criteria. These studies are summarized in Table 2.1. Evidence published before September 2009 is included in the tables in “The Evidence for Medical Nutrition Therapy for Type 1 and Type 2 Diabetes in Adults” (Franz 2010) and in the Acad Nutr Diet Evidence Analysis Library (http://www.adaevidencelibrary.com). Evidence from the Report of the Dietary Guidelines Advisory Committee (DGAC) on the Dietary Guidelines for Americans, 2010, is also referenced and is publicly available