Nutritional Approach in Management of Diabetes or Prediabetes

How effective is medical nutrition therapy in improving diabetes and prediabetes outcomes?

For people at risk of developing diabetes or people with diabetes, achieving a healthy weight, choosing healthy eating patterns, and getting regular exercise all help to improve long-term blood glucose control. Eating healthy to beat diabetes isn’t about denial and deprivation but rather making wise food adjustments for adequate nutrition.

This review is aimed at expanding the knowledge on effects of diabetes-focused medical nutrition therapy as part of an overall management plan, with the goal of improving diabetes and prediabetes outcomes in adults. The previous report on this topic focused on nutrition therapy for only adults with diabetes. The purpose of this recent report is to expand the population of the patients involved to include adults with diabetes or prediabetes and to provide healthcare professionals with evidence-based guidance.

In recent years, there has been a lot of emphasis on diet, exercise and other lifestyle modifications as management and prevention therapies for patients with diabetes. The American Diabetes Association (ADA) stresses that individualized medical nutrition therapy (MNT) is essential and should be included in the management plan for patients and these plans should be reassessed regularly between healthcare practitioners and patients with diabetes. Following dietary and exercise recommendations reduces the risk of progression from prediabetes to diabetes. Various diets have been shown to provide benefits, including Mediterranean-style diets, the Dietary Approaches to Stop Hypertension (DASH) plan, plant-based diets and low-carbohydrate diets. Unfortunately, some of these dietary plans are not recommended for special population patients, for example, pregnant or breastfeeding females, those with eating disorders, patients with a renal disease etc.

The authors of the report evaluated several studies, sources, and searches mainly from original research articles, meta-analysis, reviews, etc. Their common goal was to use nutrition therapy to promote and support healthy eating, to address individual nutrition needs, to maintain the pleasure of eating and to provide practical tools for day to day meal planning to people with diabetes. They came together severally via in-person meetings, teleconference calls, emails, and web-based meetings and reached an agreement on the recommendations they made. The Academy of Nutrition and Dietetics evidence-based nutrition practice guideline recommendations were reviewed and considered for appropriate structure for the application of medical nutrition therapy for adults with diabetes. 

The report outlined various lifestyle and dietary intervention programs. For people with prediabetes who are also overweight, it recommends a Diabetes Prevention Program (DPP) and individualized medical nutrition therapy. Dietary fiber is recommended for people with diabetes at a minimum quantity of 14g per 1,000 kcal from sources that include non-starchy vegetables, avocados, fruits, berries, beans, peas, and lentils. Two different reviewed studies comparing 32% vs. 15% energy from protein showed that participants who consumed 32% energy from protein had improvements in weight (2 kg greater weight loss), and 0.5% improvement in A1c. The dietary fat goal for patients with diabetes is the same for adults without diabetes (20-35% of calorie intake) and it is recommended to eat more food with higher total fat than certain carbohydrate foods. Fat sources from synthetic trans-fat should be greatly reduced and ruminant trans fats which are only present in minimal quantities shouldn’t be eliminated. There is no clear guideline to limit dietary cholesterol for people with diabetes and more research is required in this area.  The recommended dietary carbohydrate intake for adults without diabetes is 130 g/day, but for patients with diabetes, it is necessary to pay attention to the quality of the carbohydrate foods chosen for consumption. When making an individualized eating plan, the optimum goal is to select foods that are rich in dietary fiber, vitamins, minerals and foods that are low in added sugars, fats, and sodium to create the ideal diet for patients with diabetes.

In general, it is important to make individualized recommendations for people with diabetes and prediabetes about eating patterns which focus on: a variety of eating patterns, eating non-starchy vegetables, reduction of added sugars and refined grains, avoidance of highly processed foods, reduction of overall carbohydrate intake. Potential benefits for adhering to these recommendations include: reduced risk of diabetes, better glycemic control, A1c reduction, weight loss, reduced risk of major cardiovascular events, lowered triglycerides, lowered LDL-C, increased HDL-C, lowered blood pressure and overall general well-being.

Practice Pearls:

• To achieve a long-term adherence to medical nutrition therapy, people at risk or living with diabetes should have flexibility in food choices without compromising overall healthy diet quality.
• Risk of developing overt diabetes is largely preventable and good control of glucose level in patients with diabetes is possible by taking several simple steps involving: keeping weight under control, regular exercise, eating and maintaining a healthy diet, and not smoking.
• Generally, a focused lifestyle intervention through medical nutritional approach is effective in decreasing HbA1c level, and improving diabetes and prediabetes outcomes.

Evert, Dennison, Gardner, et al. “Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report.” Diabetes Care 2019 May; 42(5): 731-754. https://doi.org/10.2337/dci19-0014

Wylie-Rosett, Hu, et al. “Nutritional Strategies for Prevention and Management of Diabetes: Consensus and Uncertainties.” Diabetes Care 2019 May; 42(5): 727-730. https://doi.org/10.2337/dci19-0009