Marion J. Franz, MS, RDN, CDE,1 and Anne Daly, MS, RDN, CDE2
1Nutrition Concepts by Franz, Inc., Minneapolis, MN. 2Springfield Diabetes and Endocrine Center, Springfield, IL.
Ideally, individuals with diabetes should be referred to a registered dietitian/nutritionist (RDN) at or soon after diagnosis and for ongoing follow-up and support.1 Nutrition therapy is the preferred term and should be used instead of diet or dietary management. Nutrition therapy is the treatment of a disease, in this case diabetes, or condition through the modification of nutrient or whole food intake and often is provided by a wide range of health professionals.1Conversely, medical nutrition therapy (MNT) is defined as an evidence-based application of the nutrition care process provided by an RDN and can be covered as a Medicare benefit. Both nutrition therapy and MNT should involve nutrition assessment, nutrition diagnosis, nutrition interventions (e.g., education and counseling), and nutrition monitoring and evaluation with ongoing follow-up to support long-term lifestyle changes, evaluate outcomes, and modify interventions as needed. In addition to diabetes MNT provided by an RDN, diabetes self-management education and support are critical components of care for all people with diabetes and must include nutrition therapy as an essential core topic and self-care behavior.2 Unfortunately, national data indicate that only about half of the people with diabetes report receiving some type of diabetes education,3 and in a study of 18,404 patients with diabetes, only 9.1% had at least one nutrition visit within a 9-year period.4
EFFECTIVENESS OF MEDICAL NUTRITION THERAPY
As with any recommended medical therapy, an essential question first must be addressed: Is there evidence of its effectiveness? The goals of diabetes nutrition therapy include nutrition interventions that promote healthy eating and help patients achieve glucose, lipid, and blood pressure goals.1 Effective nutrition therapy interventions are reported from individual sessions and comprehensive group diabetes education programs.1,5 The documented decreases in A1C observed in these studies for individuals with type 1 diabetes (T1D) are −0.3% to −1.0% and for individuals with type 2 diabetes (T2D) are –0.5% to −2.0%. The reported A1C reductions are similar to or greater than expected from currently available glucose-lowering pharmacologic treatments for diabetes and depend on the type and duration of diabetes and the A1C level at implementation. For example, implementation of nutrition therapy in patients with newly diagnosed T2D and an A1C of ~9% resulted in a decrease of −2%,6 whereas patients newly diagnosed with an A1C of 6.6% experienced a decrease of −0.4%,7 both of which are significant and clinically meaningful. Even in patients with a long duration of T2D of ~9 years and diabetes that was not optimally controlled, implementation of intensive nutrition therapy decreased A1C levels by −0.5%, which was significant and more cost effective than adding a third medication.8
In people with T1D, implementation of nutrition therapy based on adjustments in insulin to cover planned carbohydrate intake (insulin-to-carbohydrate ratios) improved A1C by ~1% and improved quality of life without worsening of hypoglycemia or cardiovascular risk.9 Evidence also supports long-term use of insulin-to-carbohydrate ratios for improved glycemic control.10 Other studies in subjects with T1D or T2D have reported other beneficial outcomes, including improved lipid profiles, weight loss, decreased blood pressure, decreased need for medications, and decreased risk of onset and progression to diabetes-related comorbidities.5
It is essential that educators and their patients with diabetes collaboratively agree on which nutrition therapy interventions will be used, as a number of interventions have been shown to be effective. In the studies reporting effectiveness of nutrition therapy, various nutrition interventions have been implemented, reduced energy or fat intake, carbohydrate counting, simplified meal plans, healthy food or exchange choices, use of insulin-to-carbohydrate ratios, physical activity, and behavioral strategies. A unifying focus of nutrition therapy interventions for T2D calls for reduced energy intake and for T1D adjusts insulin based on planned carbohydrate intake. Multiple opportunities to provide education and counseling initially and on a continued basis are essential.5 The American Diabetes Association (the Association) recommends that people with diabetes receive individualized MNT as needed to achieve treatment goals, preferably provided by an RDN who is familiar with the components of diabetes nutrition therapy.11
ROLE OF NUTRITION THERAPY IN DIABETES PREVENTION
Strong evidence reports that nutrition therapy—reduced energy intake and regular physical activity—is beneficial for people with prediabetes.12 The incidence of T2D in the intervention groups in both the U.S. Diabetes Prevention Program (USDPP)13 and the Finnish Diabetes Program14 lifestyle intervention groups was reduced by 58%. Other large randomized controlled trials in China, Japan, and India also have demonstrated reduced risk of developing diabetes from lifestyle interventions.12 The goals of decreasing energy and fat intake to produce a modest weight loss (5–7% of body weight) and moderate physical activity (equivalent to 30 min brisk walking on most days of the week) were consistent across trials and effective in all ethnic groups, different age-groups, and various social and cultural settings worldwide. Furthermore, in individuals who maintained lifestyle interventions, the continued prevention or delayin developing diabetes has been continued for up to 20 years after the active intervention.15
High consumption of sugar-sweetened beverages, which includes soft drinks, fruit drinks, and energy and vitamin water drinks containing sucrose, high-fructose corn syrup, or fruit juice concentrates, also is associated with the development of T2D.16 Studies also have reported that an eating pattern high in saturated fatty acids and trans fatty acids is associated with increased markers of insulin resistance and risk of diabetes, whereas unsaturated fatty acid intake is inversely associated with the risk of diabetes.12 Therefore, individuals at risk for T2D should be encouraged to limit their intake of sugar-sweetened beverages and decrease saturated and trans fat intake.
Most encouraging is a study reporting that adhering to a combination of healthy lifestyle habits (a healthy eating pattern, participating in regular physical activity, maintaining a normal body weight, moderate alcohol intake, and being a nonsmoker) reduced the risk of diabetes by as much as 84% for women and 72% for men.17
ROLE OF NUTRITION THERAPY IN DIABETES MANAGEMENT
A primary goal of diabetes nutrition therapy is to promote and support healthful eating patterns, emphasizing a variety of nutrient-dense foods in appropriate portion sizes to improve overall health and to help patients achieve glucose, lipid, and blood pressure goals.1
Nutrition therapy recommended for people with diabetes often is based on theories or opinions of the medical treatment provider. People with diabetes may find this frustrating or confusing because nutritional information available to the general public often is contradictory. They hear or read that they should be on a low-carbohydrate diet from one source, but other sources say they should be eating a high-carbohydrate, high-protein, or low-fat diet.
In recent years, a shift has occurred in how nutrition therapy recommendations from professional organizations are developed. Nutrition therapy, like medical recommendations, now is developed using an evidence-based approach. The Academy of Nutrition and Dietetics (AND) published evidence-based recommendations for adults with T1D and T2D in 2010,18,19 and the Association’s 2013 nutrition therapy recommendations for the management of adults with diabetes has used a similar process creating a reliable resource for patient education and treatment.1
Nutrition Assessment and Nutrition Diagnosis
A nutrition assessment is necessary to prioritize nutrition interventions and to address individual needs based on personal and cultural preferences, health literacy and numeracy, and access to healthful food choices. Furthermore, nutrition interventions must be based on behavioral changes that the individual with diabetes is willing and able to make. Collaborating with patients involves prioritization of nutrition therapy interventions, and goals. On the basis of this assessment, the RDN can determine the nutrition diagnosis, describing nutrition-related problems and the etiology or cause and contributing risk factors to the problems.
Just as no one medication or insulin regimen applies to all people with diabetes, no one nutrition intervention applies to all people with diabetes. As reviewed in the effectiveness section, a variety of nutrition therapy approaches and eating patterns, along with multiple encounters and ongoing support have been shown to be effective for improving glycemic control and reducing cardiovascular risk in people with diabetes. The Association’s 2013 nutrition therapy recommendations for adults with diabetes provides a summary of priority topics and key strategies (summarized in Table 4.1).
Table 4.1—Key Nutrition Therapy Intervention Strategies for Adults with Diabetes
Strategies for all people with diabetes
• Follow portion control of all foods
• When choosing carbohydrate food, choose nutrient-dense, high-fiber foods whenever possible instead of processed foods with added sodium, fat, and sugars
• Avoid sugar-sweetened beverages
• Select leaner protein sources and meat alternatives
• Substitute foods higher in unsaturated fat (liquid oils) for foods high in saturated or trans fats
• Avoid the use of vitamin and mineral supplements, herbal products, or spices (e.g., cinnamon) for management of diabetes
• Limit sodium intake to 2,300 mg/day
• Moderate alcohol consumption (one drink or less for adult women and two drinks or less for adult men) has minimal acute or long-term effects on blood glucose and may have beneficial effects on cardiovascular risk; to reduce the risk of hypoglycemia for individuals using insulin or insulin secretagogues, alcohol should be consumed with food
Strategies for individuals using insulin secretagogues
• Consume moderate amounts of carbohydrate at meals (and snacks, if desired)
• Do not skip meals
Strategies for individuals with type 1 or type 2 diabetes on insulin
• Learn how to count carbohydrates or another meal planning approach to quantify carbohydrate intake; the objective is to “match” mealtime insulin to carbohydrate consumed
• If on multiple-daily injection plans or an insulin pump, take mealtime insulin before eating
• If on a premixed or fixed insulin plan, eat meals at similar times every day and ensure that they contain similar amounts of carbohydrate that match set doses of insulin
Individual key strategies
• Assess the individual’s current eating pattern, preferences, and metabolic goals
• Develop nutrition therapy goals collaboratively with the individual
• Select a meal planning approach or eating pattern based on the individual’s personal and cultural preferences, their literacy and numeracy, and their readiness, willingness, and ability to change
• Facilitate behavioral change and achievement of metabolic goals while meeting the patient’s preferences
• Monitor outcomes and provide ongoing support; recommendations may need to be adjusted over time based on changes in life circumstance, preferences, and disease course.
Source: Reprinted with permission from Diabetes Care 2013;36:3821–3842.
Priorities for People on Nutrition Therapy Alone orGlucose-Lowering Medications
Nutrition therapy often begins with lifestyle strategies that reduce energy intake and increase energy expenditure through physical activity. A healthful eating pattern is recommended to promote weight loss and prevent future weight gain. Many individuals, however, already have tried unsuccessfully to lose weight, and it is important to note that other lifestyle strategies, even without weight loss, can improve glycemia. These strategies include reducing energy intake, monitoring of carbohydrate servings, limiting consumption of saturated fats, and increasing physical activity.
Weight loss to improve glycemic control is most beneficial for people with prediabetes or those who are early in the diabetes disease process. A weight loss of >6 kg (~7–8% loss of initial body weight), regular physical activity, and frequent contact with RDNs appear to be important for consistent beneficial effects of weight-loss interventions on glycemia, lipids, and blood pressure.20 Because nutrition therapy goals are broader than just weight loss, nutrition therapy is essential throughout the disease process. Teaching which foods are carbohydrates, average portion sizes, and how many servings to select at meals (and snacks, if desired) can be an effective first step in food and meal planning.
Priorities for People Requiring Insulin Therapy
The first priority for individuals who require insulin therapy is to develop an eating plan and then integrate an insulin regimen into their desired eating patterns and physical activity schedules. Physiological insulin regimens involving multiple injections or use of an insulin pump give the individual freedom in timing and composition of meals. Approximately half of the required insulin is given as basal insulin, and the other half is divided and given as rapid-acting insulin before meals. The total amount of carbohydrate in the meal is the major determinant of the premeal rapid-acting insulin dose.9 After determining the amount of insulin required to cover the individual’s usual meal carbohydrate, adjustments in mealtime insulin can be made based on the amount of carbohydrate they are planning to eat (insulin-to-carbohydrate ratios). For people on fixed insulin regimens and who are not adjusting insulin doses, consistency of day-to-day carbohydrate at meals is recommended.
Macro- and Micronutrient Recommendations
In the U.S., the majority of people with T1D or T2D report eating moderate amounts of carbohydrate (~45% of total energy intake) and ~35% to 40% of energy intake from fat, with the remainder (~16–18%) coming from protein.21Review of the evidence shows clearly that there is not an ideal percentage of macronutrients for people with diabetes.22 Total energy intake is more important than the source of the energy. No evidence indicates that vitamin or mineral supplementation is beneficial in people with diabetes who do not have underlying deficiencies.23
Recommendations for alcohol consumption for people with diabetes are the same as for the general population. Adults choosing to consume alcohol should limit their intake to one serving or less per day for women and two servings or less per day for men.1 One alcohol-containing beverage is defined as 1.5 ounces of distilled spirits, 5 ounces of wine, or 12 ounces of beer, each containing approximately 15 g of ethanol. The type of alcoholic beverage does not influence the potential beneficial effects on glycemia and reduction of cardiovascular risk in people with diabetes.24 Abstinence is recommended for people with risks related to alcohol consumption.
Just as people with diabetes do not eat a single type of macronutrient, they also do not eat a single type of food. Foods are eaten in combinations, and thus it is important to review the relationship between eating patterns (combinations of different foods or food groups) and disease. A review of research on Mediterranean-style, vegetarian and vegan, low-fat, low-carbohydrate, and Dietary Approaches to Stop Hypertension (DASH) eating patterns that included participants with diabetes concluded that a variety of eating patterns are acceptable for the management of diabetes.1 Personal preferences and metabolic goals should be considered when recommending one eating pattern over another.
The Association and AND have copublished diabetes nutrition therapy educational resources, which are designed to reflect the most recent nutrition recommendations, updated nutrient composition data, consumer trends, and feedback from educators. These resources include the following:
• Choose Your Foods: Food Lists for Diabetes (Spanish language version also available: Seleccione Sus Alimentos: Listas de Alimentos para la Diabetes)
• Count Your Carbs: Getting Started
• Match Your Insulin to Your Carbs
• Choose Your Foods: Plan Your Meals (Spanish language version also available: Seleccione Sus Alimentos: Planifique Sus Comidas)
• Eating Healthy with Diabetes: An Easy Reading Guide
• Healthy Food Choices
• Choose Your Foods: Food Lists for Weight Management
These publications can be ordered from the Association at 1-800-DIABETES or online.25–31 In addition, the Association’s online nutrition tool MyFoodAdvisor® (http://tracker.diabetes.org) provides an interactive resource for people withdiabetes.
Nutrition Monitoring and Evaluation
Nutrition interventions are most effective when they are monitored and evaluated on a regular basis. For example, at approximately 6 weeks after the initial nutrition session, the individual meets with the RDN to evaluate progress toward achieving personal goals. If no progress is evident, they should reassess and consider possible revisions to the nutrition care plan. At 3 months, the RDN can recommend changes in medical therapy (medications added or adjusted) if glycemic goals have not been met, the individual has lost weight with no improvement in glucose, the individual is doing well with the eating plan and physical activity and further nutrition interventions are unlikely to improve metabolic outcomes, or if the individual has done all that she or he can or is willing to do.
ROLE OF PHYSICAL ACTIVITY INRISK FACTOR REDUCTION ANDDIABETES MANAGEMENT
Physical activity should be an integral part of the treatment plan for people with diabetes. For all people with diabetes, physical activity can improve insulin sensitivity, independent of weight loss; reduce cardiovascular risk factors; help control weight; and bring about a healthier mental outlook. Increased insulin sensitivity results in increased peripheral use of glucose not only during but also after the activity. This enhanced insulin sensitivity, however, is lost within 48 h after exercise and repeated bouts of exercise at regular intervals are important. Regular physical activity is also essential for the prevention of T2D in high-risk individuals. In people with T2D, it can improve blood glucose levels acutely and, if done regularly, improve A1C as well. Both resistance and aerobic exercise result in improved glucose control and several studies have demonstrated a greater beneficial impact from a combination program of strength and aerobic exercise.32,33
Given appropriate guidelines, most people with diabetes can safely participate in physical activities. Past Association guidelines suggested that patients with diabetes and multiple cardiovascular risk factors be assessed for coronary artery disease (CAD) before beginning a program of physical activity. Because the area of CAD screening remains unclear, however, the Association now recommends that providers use clinical judgment and encourage high-risk patients to start with short periods of low-intensity activity and increase the intensity and duration gradually over time.11
The type of physical activity individuals choose should be tailored to their physical capacity and interest. In general, adults with diabetes should be advised to perform at least 150 min/week of moderate-intensity aerobic physical (50–70% of maximum heart rate), distributed over at least 3 days/week with no more than 2 consecutive days without physical activity. In the absence of contraindications, people with T2D should be encouraged to perform resistance exercise at least twice a week. Children with diabetes or prediabetes should be encouraged to engage in at least 60 min of physical activity each day.11
Strong evidence supports the effectiveness of nutrition therapy across the continuum of diabetes management. For all people with diabetes, the goals of nutrition therapy are to promote healthy eating patterns to assist in achieving and maintaining glucose, lipid, blood pressure, and body weight goals. The nutrition therapy interventions selected must meet the individual’s goals and lifestyle and the individual with diabetes must be willing and able to implement the recommended strategies.
1. Evert AB, Boucher JL, Cypress M, Dunbar DA, Franz MJ, Mayer-Davis EJ, Neumiller JJ, Nwankwo R, Verdi CL, Urbanski P, Yancy WS Jr. Nutrition therapy recommendations for the management of adults with diabetes.Diabetes Care 2013;36:3821–3842
2. Haas L, Maryniuk M, Beck J, Cox CE, Duker P, Edwards L, Fisher EB, Hanson L, Kent D, Kolb L, McLaughlin S, Orzeck E, Piette JD,Rhinehart AS, Rothman R, Sklaroff S, Tomky D, Youssef G on behalf of the 2012 Standards Revision Task Force. National standards for diabetes self-management education and support. Diabetes Care 2014;37(Suppl. 1):S144–S153
3. Ali MK, Bullard KM, Saaddine JB, Cowie CC, Imperatore G, Gregg EW. Achievement of goals in U.S. diabetes care, 1999–2010. N Engl J Med 2013;368:1613–1624
4. Robbins JM, Thatcher GE, Webb DA, Valdmanis VG. Nutritionist visits, diabetes classes, and hospitalization rates and charges: The Urban Diabetes Study. Diabetes Care 2008;31:655–660
5. Pastors JG, Franz MJ. Effectiveness of medical nutrition therapy in diabetes. In American Diabetes Association Guide to Nutrition Therapy for Diabetes. Franz MJ, Evert AB, Eds. Alexandria, VA, American Diabetes Association, 2012, p. 1
6. U.S. Prospective Diabetes Study (UKPDS). Response of fasting plasma glucose to diet therapy in newly presenting type II diabetic patients. Metabolism 1990;39:905–912
7. Andrews RC, Cooper AR, Montgomery AA, Norcross AJ, Peters TJ, Sharp DJ, Jackson N, Fitzsimons K, Bright J, Coulman K, England CY, Groton J, McLenaghan A, Paxton E, Polet A, Thompson C, Dayan CM. Diet or diet plus physical activity versus usual care in patients with newly diagnosed type 2 diabetes: the Early ACTID randomized controlled trial. Lancet 2011;378:129–139
8. Coppell KJ, Kataoka M, Williams SM, Chisholm AW, Vorgers SM, Mann JI. Nutritional intervention in patients with type 2 diabetes who are hyperglycaemic despite optimized drug treatment—Lifestyle Over and Above Drugs in Diabetes (LOADD) study: randomized controlled trial. BMJ 2010;341:c3337
9. DAFNE Study Group. Training in flexible, intensive insulin management to enable dietary freedom in people with type 1 diabetes. Dose Adjusted for Normal Eating (DAFNE) randomized controlled trial. BMJ2002;325:746–752
10. Speight J, Amiel SA, Bradley C, Heller S, Oliver L, Roberts S, Rogers H, Taylor C, Thompson G. Long-term biomedical and psychological outcomes from DAFNE (Dose Adjusted for Normal Eating) structured education to promote intensive insulin therapy in adults with sub-optimally controlled type 1 diabetes. Diabetes Res Clin Pract 2010;89:22–29
11. American Diabetes Association. Standards of medical care in diabetes—2014. Diabetes Care 2014;37(Suppl. 1):S14–S80
12. Youssef G. Nutrition therapy and prediabetes. In American Diabetes Association Guide to Nutrition Therapy for Diabetes. Franz MJ, Evert AB, Eds. Alexandria, VA, American Diabetes Association, 2012, p. 469
13. Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention of metformin. N Eng J Med 2002;346:393–403
14. Tuomilehto J, Lindstrom J, Eriksson JG, Valle TT, Hamalainen H, Ilanne-Parikka P, Keinanen-Kiukaanniemi S, Laakson M, Louheranta A, Rastas M, Salminen V, Uusitupa M, for the Finnish Diabetes Prevention Study Group. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med 2001;344:1343–1350
15. Li G, Zhang P, Wang J, Gregg EW, Yang W, Gong Q, Li H, Jiang Y, An Y, Shuai Y, Zhang B, Zhang J, Thompson TJ, Gerzoff RB, Roglic G, Hu Y, Bennett PH. The long-term effect of lifestyle interventions to prevent diabetes in the China Da Qing Diabetes Prevention Study: a 20-year follow-up study. Lancet 2008;371:1783–1789
16. Malik VS, Popkin BM, Bray GA, Despres JP, Willett WC, Hu FB. Sugarsweetened beverages and risk of metabolic syndrome and type 2 diabetes. Diabetes Care 2010;33:2477–2483
17. Reis JP, Loria CM, Sorlie PD, Park Y, Hollenbenck A, Schatzkin A. Lifestyle factors and risk of new-onset diabetes: a population-based cohort study. Ann Intern Med 2011;155:292–299
18. Academy of Nutrition and Dietetics. Diabetes type 1 and 2 evidence-based nutrition practice guidelines for adults. 2008. Available from http://andeal.org/topic.cfm?menu=5305&cat=1618. Accessed 26 September 2014
19. Franz MJ, Powers MA, Leontos C, Holzmeister LA, Kulkarni K, Monk A, Wedel N, Gradwell E. The evidence for medical nutrition therapy for type 1 and type 2 diabetes in adults. J Am Diet Assoc 2010;110:1852–1880
20. Franz MJ. The obesity paradox and diabetes. Diabetes Spectrum 2013;26:145–151
21. Oza-Frank R, Cheng YJ, Narayan KM, Gregg EW. Trends in nutrient intake among adults with diabetes in the United States: 1988–2004. J Am Diet Assoc 2009;109:1173–1178
22. Wheeler ML, Dunbar SA, Jaacks LM, Karmally W, Mayer-Davis EJ, Wylie-Rosett J, Yancy Jr WS. Macronutrients, food groups and eating patterns in the management of diabetes: a systematic review of the literature. Diabetes Care 2010;35:434–445
23. Neumiller JJ. Micronutrients and diabetes. In American Diabetes Association Guide to Nutrition Therapy for Diabetes. Franz MJ, Evert AB, Eds. Alexandria, VA, American Diabetes Association, 2012, p. 41
24. Franz MJ. Alcohol and diabetes. In American Diabetes Association Guide to Nutrition Therapy for Diabetes. Franz MJ, Evert AB, Eds. Alexandria, VA, American Diabetes Association, 2012, p. 69
25. Academy of Nutrition and Dietetics and American Diabetes Association. Choose Your Foods: Food Lists for Diabetes. 2014. Available from http://store.diabetes.org/1586-Choose-Your-Foods-Food-Lists-for-Diabetes-25-Pkg.aspx. Accessed 28 January 2017
26. Academy of Nutrition and Dietetics and American Diabetes Association. Count Your Carbs: Getting Started. 3rd ed. 2014. Available from http://store.diabetes.org/1591-Count-Your-Carbs-3rd-Edition-10-Pkg.aspx. Accessed 28 January 2017
27. Academy of Nutrition and Dietetics and American Diabetes Association. Match Your Insulin to Your Carbs. 3rd ed. 2014. Available from http://store.diabetes.org/1590-Match-Your-Insulin-to-Your-Carbs-3rd-Edition-10-Pkg.aspx. Accessed 28 January 2017
28. Academy of Nutrition and Dietetics and American Diabetes Association. Choose Your Foods: Plan Your Meals. 2nd ed. 2014. http://store.diabetes.org/1621-Choose-Your-Foods-Plan-Your-Meals-2nd-Edition-25-Pkg.aspx. Accessed 28 January 2017
29. Academy of Nutrition and Dietetics and American Diabetes Association. Eating Healthy with Diabetes: An Easy Reading Guide. 4th ed. 2014. Available from http://store.diabetes.org/1620-Eating-Healthy-with-Diabetes-4th-Edition.aspx. Accessed 28 January 2017
30. Academy of Nutrition and Dietetics and American Diabetes Association. Healthy Food Choices. 4th ed. 2014. Available from http://store.diabetes.org/1619-Healthy-Food-Choices-4th-Edition-25-Pkg.aspx. Accessed 28 January 2017
31. Academy of Nutrition and Dietetics and American Diabetes Association. Choose Your Foods: Food Lists for Weight Management. 2014. http://store.diabetes.org/1588-Choose-Your-Foods-Food-Lists-for-Weight-Management-25-Pkg.aspx. Accessed 28 January 2017
32. Sigal RJ, Kenny GP, Boule NG, Wells GA, Prudhomme D, Fortier M, Reid RD, Tulloch H, Coyle D, Phillips P, Jennings A, Jaffey J. Effects of aerobic training, resistance training, or both on glycemic control in type 2 diabetes: a randomized controlled trial. Ann Intern Med 2007;147:357–369
33. Church TS, Blair SN, Cocreham S, Johannsen N, Johnson W, Kramer K, Mikus CR, Myers V, Nauta M, Rodarte RQ, Sparks L, Thompson A, Earnest CP. Effects of aerobic and resistance training on hemoglobin A1c levels in patients with type 2 diabetes: a randomized controlled trial. JAMA 2010;304:2253–2262