Diet advice for people with diabetes is changing. After decades of favoring high-carbohydrate, low-fat diets, a report shared at the American Diabetes Association (ADA) Scientific Sessions noted that other diet options gave better diabetes and cardiovascular disease (CVD) outcomes than the former standard ADA diet. Here are some of the beneficial eating patterns that were discussed:
The Dietary Approaches to Stop Hypertension (DASH) diet was found to lower blood pressure and risk of diabetes, and it helped people lose weight. It’s also easy to follow. Writing in Diabetes Spectrum, Certified Diabetes Educator and Registered Dietitian Amy Campbell noted that “The appeal of the DASH eating pattern is that it is practical; it does not require special foods or supplements, and it is an approach that is appropriate for patients’ entire family to follow.”
DASH includes plenty of fruits, vegetables and whole grains; fat-free or low-fat milk and milk products; lean meat and poultry; fish; and nuts. You can learn more about the DASH diet here.
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A very-low-carb diet (VLCD) was shown to reduce A1C (a measure of glucose control over the previous 2–3 months), reduced blood pressure and weight, lower triglyceride (serum fat) levels and give higher levels of high-density lipoprotein (HDL, or “good” cholesterol). A VLCD is strict, allowing only 20–50 grams of carbohydrate a day — the equivalent of a few pieces of bread.
Less strict low-carb diets (LCD), prescribing 25–40% of daily calories from carbs, also showed benefits when compared to typical American diets (generally about 45% carbohydrate) or the old-fashioned ADA diet (about 50% carb.) Like DASH, low-carb diets stress vegetables, especially non-starchy ones such as salad greens, broccoli, cauliflower, cucumber, cabbage, and cooked greens. Both approaches favor plant fats, such as nuts, avocado, oils and nut butters. Unlike DASH, though, low-carb diets approve of animal fats such as butter, and of meat. Both diets approve protein in the form of lean meat, poultry, and fish, but disagree on fattier meats, eggs and cheese.
Some low-carb plans include fruit (such as berries) and a greater array of vegetables. All avoid starchy and sugary foods such as pasta, rice, potatoes, bread and sweets. Learn more about the application of low-carb diets in type 1 diabetes and learn more here about using low-carb in type 2 diabetes. You can also learn about research indicating that eating a low-carb breakfast can keep blood sugar levels down all day.
The ADA 2019 Standards of Medical Care in Diabetes added low-carb nutrition to recommended patterns of eating for type 2 diabetes.
Many studies have shown that reducing or eliminating animal products from your diet reduces the risk of diabetes, lower A1C and LDL (“bad”) cholesterol and promotes weight loss. Vegetarian means not eating meat; vegan means avoiding all animal products such as dairy and lard. The ADA has added these options to its list of approved diabetes nutrition plans.
The Mediterranean diet also ranks high for managing diabetes and heart disease. Similar to DASH, Mediterranean-style diets tend to be rich in vegetables, fruits, grains, beans, nuts, olive oil and fish. Small amounts of red wine are also encouraged. Mediterranean eating patterns reduce the risk of diabetes and cardiovascular events and lower A1C and triglyceride levels.
Additional highlights of the ADA nutrition report
The ADA summarizes their new nutritional advice in this recap, highlighting how healthy eating varies between people. The best food for you might not be good for me.
Some other tips from the new ADA report:
All patients can benefit from Medical Nutrition Therapy (MNT), meeting with a dietitian to figure out meal plans. A team led by William Yancy, MD, wrote, “Patients’ improvement in A1c levels with MNT were similar or greater than would be expected with medication.” If your insurance covers a dietitian consult, you might ask for one.
As reported in the Dietary Guidelines for Americans, adults with or without diabetes should eat a minimum of 14 grams of fiber for each 1,000 calories of food. Fiber is available in vegetables, pulses, beans, berries and whole grains, as well as in fiber supplements. Make sure to increase fluid intake when you increase fiber.
When you eat matters
When you eat can be as important as what you eat. Courtney Peterson, PhD, of the University of Alabama, Birmingham, reported on her experiments with early time-restricted feeding (eTRF). The idea of eTRF is to “eat in sync with our biological clocks (or circadian rhythms) by eating early in the day.” The style of eating “has already been shown to reverse or prevent diabetes/insulin resistance, high cholesterol levels, inflammation, and obesity in rodents,” she writes. “Now we are testing it in humans. In her studies, subjects fast for 14 or more hours a day. Nearly all eating is done in the morning; nothing is eaten after 3 PM, as some religious orders have long practiced. The morning eaters have had better insulin sensitivity, lower blood pressure and less hunger than those who ate later. According to Dr. Peterson, “If you eat late at night, it’s bad for your metabolism. Our bodies are optimized to do certain things at certain times of the day.”
She reported that on the oral glucose tolerance test (OGTT), used to diagnose diabetes, some people have prediabetes in the morning but diabetes in the afternoon. In studies, mice who ate at night gained more weight than those who ate the same food in daytime. Also in studies, after one week, women who ate big breakfasts and small dinners had lower insulin and glucose levels; they felt less hunger and lost weight.
Other forms of intermittent fasting also show promise. Rona Antoni, PhD, of the University of Surrey reported that fasting plans like 5:2, in which people eat normally for five days and have two days of very low intake, can cause equal amounts of weight loss, and possibly healthier weight loss — losing more fat and less muscle mass — than constant restricted eating.
Dr. Antoni cautioned that more human studies are needed. And Dr. Peterson advised, “What you eat still matters more,” cautioning that diabetes medications will need to be changed and monitored when people start a time-restricted eating or intermittent fasting plan.