What can I eat? If you’re like a lot of people with diabetes or prediabetes, that was likely the first question you asked after your doctor delivered the diagnosis. A new report from the American Diabetes Association (ADA), published in the May 2019 issue of Diabetes Care, provides some answers based on recent research. Here are some of the highlights from the report.
This article was originally published in Diabetes Forecast.
The report, which the ADA commissions every five years, gives doctors, dietitians, and other members of your health care team recommendations as they provide therapy and guidance. A committee of clinicians, researchers, and ADA staffers looked at more than 600 diabetes nutrition studies published between January 2014 and February 2018. Nutrition interventions in the studies ranged from programs focused on weight loss to alcohol’s effect on blood glucose levels. Based on high-quality evidence, the committee came to an agreement on specific nutrition therapy recommendations that focus on adults living with prediabetes and type 1 and type 2 diabetes.
Really. Given the wide spectrum of ages, health statuses, diabetes durations, budgets, and eating preferences within the diabetes community, it’s no surprise a buffet of nutrition approaches is needed for managing type 1 and type 2 diabetes. The report encourages providers to make a referral for diabetes-focused medical nutrition therapy, provided by a registered dietitian or registered dietitian nutritionist, at diagnosis and then as needed. Nutrition education has been shown to help people with diabetes achieve blood glucose and weight management goals, and help prevent and treat complications.
A variety of eating patterns can help you manage your diabetes—from Mediterranean-style to vegetarian or vegan. “The report highlights the relative benefits and potential pitfalls of various approaches so that providers and patients can pursue any of them with this information in hand,” says William Yancy, MD, a professor at Duke University School of Medicine, one of the report’s coauthors, and cochair of the committee. Focus on these tips, no matter what eating pattern you choose:
There is no perfect percentage of calories from macronutrients (carbohydrate, protein, and fat) for people with or at risk for diabetes. Instead, the macro percentages can and should be individualized. “The quality and quantity of foods consumed are key,” says coauthor and committee cochair Alison Evert, MS, RD, CDE, a dietitian and certified diabetes educator at the University of Washington Medical Center.
“There is growing research to show that low-carbohydrate eating patterns can benefit people with diabetes and prediabetes,” Yancy says. There’s no one definition, however, for “low carb.” Studies of diets in which carbs made up 26 to 45 percent of total calories showed blood glucose benefits, a reduction in diabetes medications, and improvement in heart disease risk factors. Though the brain requires glucose, the report mentions that the body meets that need via other processes: by using carbohydrate stored in the liver, making new glucose from stored fat and protein, or burning stored fat when carb intake is very low (known as ketogenesis).
A wide range of weight-loss strategies, including dietary change, physical activity, medications, and surgery, can improve blood glucose levels and other diabetes outcomes—in type 1 as well as type 2 diabetes. “Important components of effective weight-loss programs or therapy include an individualized eating plan that results in fewer calories in combination with more physical activity,” says Evert. For type 2, the benefits of weight loss are progressive, and even a 5 percent weight loss makes a difference. Even better: 15 percent or more, as needed, if it can be safely achieved.
Food swaps can help people with diabetes reduce the risk for or slow the progression of cardiovascular disease and diabetic kidney disease. For instance, replace foods high in saturated fat (such as butter and beef) with those that are rich in unsaturated fats (such as olive oil and fatty fish). Evidence shows that this type of swap reduces total cholesterol and LDL (“bad”) cholesterol and reduces your risk for cardiovascular disease. People with type 2 who replace high-carbohydrate foods with low-carb alternatives that are higher in healthy fats can improve blood glucose levels, triglycerides, and HDL (“good”) cholesterol; research is lacking in type 1 diabetes.
Studies on how food affects health are key, but nutrition research in general isn’t without its challenges. Take, for instance, study length. Research and clinical experience can show the powerful effect of nutritional interventions on diabetes over the short term, but there’s a lack of high-quality, longer-term studies with clear endpoints, such as disease development or death. To fill the void, researchers will sometimes look to observational studies, in which aspects about participants, such as which foods they eat, are observed and analyzed.
The challenge: A wide variety of eating patterns exist—along with an equally wide variety of study designs and results. “It is difficult to find a large sample of people who are clearly following certain eating plans that have demonstrated benefit,” says William Yancy, MD, a professor at Duke University School of Medicine. “These issues make it difficult to support any one specific approach [over another].”
