Research has shown that losing even small amounts of weight — as little as ten pounds over two years — can reduce the risk of developing diabetes by up to 30 percent. Among people with diabetes, weight loss improves insulin sensitivity and glycemic control, reduces triglycerides and LDL (“bad”) cholesterol, and lowers blood pressure. That is to say, losing a few pounds may very well save your life. But healthy eating for diabetes prevention or control is about more than weight loss.
During digestion, carbohydrates break down to create glucose, which enters the bloodstream, triggering a rise in insulin, which is necessary for the glucose to enter cells. In people with diabetes, this system is defective, so glucose stays in the blood. This is what you are checking when you test your blood-sugar level.
You have no doubt heard about the concept of the glycemic index (GI). GI is a measure of how fast and how high a particular food will raise blood sugar. Foods with a high GI raise blood sugar faster and higher than foods with a low GI. It’s a controversial topic in nutrition because when it comes right down to it, GI values are very confusing and often give the wrong impression. For instance, the GI value of potato chips or french fries is lower than baked potatoes. So, should you choose french fries over a baked potato? Of course not! Although the large amounts of fat in these foods slow down the rate at which they are digested, therefore giving them a lower GI rating, they’re higher in calories and lower in nutrients, making them a bad choice. There’s an easier way to achieve low-glycemic eating without feeling like you need an interpreter to help you decide on every meal. If you’re looking for foods that raise blood-sugar levels slowly and gently like rolling waves, choose high-quality carbohydrates (see list below) instead of low-quality carbs, and whenever possible, couple these carbs with protein and/or healthy fat. For example, eat brown rice and vegetables (high-quality carbs) together with grilled chicken or pork tenderloin (lean protein). High-quality carbs are full of vitamins, minerals, and fiber. They are found primarily in plant foods, including whole-grain breads and cereals, brown and wild rice, oats, vegetables, and legumes. In addition, some of these high-quality carbs also contain soluble fiber, a component of plant cell walls.
Soluble fiber slows the absorption of glucose from food in the stomach, which also helps blunt the rise in blood sugar. Studies have shown that eating a diet rich in whole grains and high-fiber foods may reduce the risk of diabetes by between 35 and 42 percent.
BEST FOODS FOR HIGH-QUALITY CARBS:
Vegetables, fruits (fresh and frozen, unsweetened), beans, peas, lentils, brown rice, wild rice, barley, oatmeal, whole-grain cereals, whole-grain breads, whole-grain crackers, quinoa, amaranth, wheat berries, millet
BEST FOODS FOR SOLUBLE FIBER:
Psyllium seeds (ground), oat bran, rice bran, oatmeal, barley, lentils, brussels sprouts, peas, beans (kidney, lima, black, navy, pinto, soy and garbanzo), apples, blackberries, pears, oranges, grapefruit, cantaloupe, strawberries, bananas, peaches, broccoli, carrots, cauliflower, cabbage, spinach, sweet potatoes, yams, white potatoes, tomatoes, avocado, raspberries, corn, almonds, flaxseed (ground), chia seeds, sunflower seeds
Low-quality carbs, on the other hand, have much less nutritional value. They are made primarily of sugar, including sugar itself, candy, soft drinks, syrup, honey, jam and jelly, cakes, and most other foods we typically think of as sweets or desserts. Refined starches — the “white” carbs, such as white rice and white bread — are also low-quality carbohydrates because they act very much like sugars once you begin to digest them. You should also avoid drinking fruit juice — all fruit juice, even those brands made from 100 percent pure fruit. Although these beverages certainly provide better nutrition than soft drinks, they contain high concentrations of fruit sugar and raise blood sugars quickly. The same thing goes for dried fruit. Like fruit juice, dried fruit provides ample nutrition and fiber, but unfortunately when the water content is removed from fresh fruit, the dried, dehydrated version becomes super-concentrated with sugar as well and can cause a sharp rise in blood sugar. Clearly not worth the spike! Starchy vegetables — such as potatoes, winter squash, peas, and corn — have a
higher glycemic index than other, nonstarchy veggies, such as broccoli, cauliflower,
cucumbers, peppers, green beans, spinach, and mushrooms. However, you can enjoy
moderate amounts of starchy vegetables if you eat them alongside lean protein at
meals (instead of eating them alone). For example, a balanced dinner might include broiled salmon, broccoli, and a small baked white or sweet potato topped with fat-free sour cream; grilled chicken, a tossed salad, and an ear of corn. Your goal, then, is to choose high-quality carbohydrates instead of low-quality carbs whenever possible, severely limiting — at the very least — if not avoiding completely, most low-quality carbs.
Moderate Total Carbohydrate, Coupled With Protein
If you stick with high-quality carbs, can you eat as much as you want? Unfortunately, no. To best control your blood sugars, you have to moderate ALL carbs — even if they’re the best of the best carbohydrates. Your total carb intake should be limited to about 40 percent of your daily food intake. (Read more about carb-counting.) To further slow or prevent a blood-sugar rise, remember that, in general, carbs should be eaten together with high-quality protein. Some foods make it easy for you: They contain both high-quality carbohydrates and lean protein — lentils, beans, yogurts, milk, split peas, and soybeans, for example.
BEST FOODS FOR HIGH-QUALITY PROTEIN:
Skinless turkey and chicken, fish and shellfish, pork tenderloin, lean beef, egg whites, yogurt (fat-free, low-fat), milk (fat-free, 1 percent low-fat), cheese (fat-free, reduced-fat), starchy beans (including black, navy, pinto, garbanzo, kidney), lentils, split peas, tofu, tempeh, soybeans, nuts and nut butters, seeds and seed butters.
Healthy Fats Versus Saturated and Trans Fats
All fats are not created equal — some can decrease your risk of diabetes and complications, while others are downright dangerous. Let’s talk about the bad fats first.
Avoid Saturated Fats. Saturated fats are found in animal-based foods, including meats, butter, whole-milk dairy products (including regular yogurt, cheese, and ice cream), and poultry skin. They are also found in some high-fat plant foods, including palm oil. Some studies have shown that eating a diet with lots of saturated fats can lead to insulin resistance and may increase the risk of diabetes by up to 20 percent. In addition, many studies confirm that saturated fats increase the risk of heart disease.
- Avoid: butter, cream cheese, lard, sour cream, doughnuts, cake, cookies, white and milk chocolate, ice cream, pizza, cream- or cheese-based salad dressing, cheese sauce, cream sauces, animal shortenings, high-fat meats (including hamburgers, bologna, pepperoni, sausage, bacon, salami, pastrami, spareribs, and hot dogs), high-fat cuts of beef and pork, whole-milk dairy products
- Choose: lean meat only (including skinless chicken and turkey, lean beef, lean pork), fish and shellfish, reduced-fat or fat-free dairy products, and soy foods (tofu, tempeh, soy milk, edamame)
- Always remove skin from poultry.
- If a food label lists palm oil and the saturated fat content is more than 2 grams per serving, put the package back on the shelf.
- Prepare foods by baking, roasting, broiling, boiling, poaching, steaming, grilling, or stir-frying in healthy oils, such as olive and canola
Avoid Trans Fats. Trans fats are worse than saturated fats for diabetes and its associated complications. The main source of trans fat is partially hydrogenated oil, which is found in most stick margarines, as well as some packaged baked goods, snack foods, fried foods, and fast-food items. (Although fortunately, most major fast-food chains have now gone trans fat–free.) By substituting vegetable oil for trans fats, you may be able to reduce your risk of diabetes by about 40 percent, and you can reduce your risk of heart disease by 53 percent. Whether you already have diabetes or are working to prevent it, there is no amount of trans fats you can safely incorporate into your diet.
Incorporate Healthy Fats.
Incorporating healthy fats into your diet is important for
blood sugar control. Fat, as well as protein, blunts the rise in blood sugar at
meals by slowing down the body’s absorption of carbohydrate. When it comes to overall health, the best fats are omega-3s
and monounsaturated fats. Both improve cholesterol levels and other cardiovascular
risk factors, so they’re a win-win for people with diabetes. Consider using olive
and canola oil for cooking, swapping steak for salmon, adding a thin slice of avocado
to your next sandwich, tossing olives into your salad, and snacking on a handful
of nuts instead of sweets.
BEST SOURCES OF OMEGA-3 FATTY ACIDS:
Wild salmon (fresh, canned), herring, mackerel (not king), sardines, anchovies, rainbow trout, Pacific oysters, flaxseed (ground), chia seeds, walnuts, butternuts (white walnuts), seaweed, walnut oil, canola oil, flaxseed oil, soybeans (edamame).
Monounsaturated fats, found in olive oil and nuts, are generally considered among the healthiest of fats. Research into the effects of olive oil on diabetes has been limited, but one Danish study found that people who ate a diet high in monounsaturated fats and low in low-quality carbohydrates had lower fasting blood glucose, lower average glucose levels, and lower peak blood-glucose responses. Monounsaturated fats also improve heart health — an especially important benefit for diabetics, who are at increased risk for heart disease and stroke. Consider using olive oil and canola oil for cooking, adding a thin slice of avocado on your next sandwich, tossing olives into your salad, and snacking on an ounce of healthy nuts instead of sweets.
BEST FOODS FOR MONOUNSATURATED FATS:
Olive oil and olives, canola oil, avocado, macadamia nuts, hazelnuts, pecans, almonds, peanuts, cashews, Brazil nuts, pistachio nuts, pine nuts, peanut butter, and other nut butters.
Other Vitamins and Minerals
Calcium and Vitamin D. According to the Nurses’ Health Study, which followed more than 83,000 women for 20 years, both calcium and vitamin D may help prevent type 2 diabetes. Women who got at least 800 IU vitamin D and 1,200 mg calcium reduced their risk of diabetes by 33 percent.
Scientists are unclear about exactly what these nutrients do
to reduce diabetes risk. It could be that vitamin D regulates the insulin-producing
cells of the pancreas, and calcium may improve insulin sensitivity. Of course, the
synergy between the two makes sense—the body can’t efficiently absorb or use calcium
without vitamin D. Improvements in insulin sensitivity are important for everyone
with diabetes, but calcium also seems to help control blood pressure, which contributes
to heart disease. So whether you have prediabetes or diabetes, calcium and vitamin
D are essential to your health.
I recommend that women aim to eat at least three servings of calcium-rich foods daily and consider taking a calcium supplement if they can’t reliably fit calcium into their meals. Men should eat no more than two or three servings of calcium-rich foods daily and should never take a calcium supplement without approval from their doctors — some early research suggests that high calcium diets may increase the risk of prostate cancer incidence and mortality.
BEST FOODS FOR VITAMIN D:
Wild salmon (fresh, canned), mackerel (not king), sardines, herring, milk (fat-free, 1 percent low-fat), soy milk, fortified yogurt, egg yolks, UV-treated mushrooms
BEST FOODS FOR CALCIUM:
Yogurt (fat-free, low-fat), milk (fat-free, 1 percent low-fat), soy milk, cheese (fat-free, reduced-fat), tofu with calcium (check nutrition label), soybeans (edamame), frozen yogurt( fat-free, low-fat), low-fat ice cream, bok choy, kale, collard greens, white beans, broccoli, almonds and almond-butter.
Magnesium. A 2010 study found that people who consumed significant amounts of magnesium
from food and supplements slashed their risk of diabetes in half compared to people
who took in very little magnesium. Higher magnesium intake was also linked to lower
levels of inflammation and better insulin sensitivity, which may explain why magnesium
is so beneficial. Whether you currently have diabetes or you’re trying to drive
down your risk, strive to add more magnesium-rich foods to your diet. Because most
people don’t get enough magnesium from food alone, consider taking a multivitamin
that provides at least 25% DV of magnesium.
BEST FOODS FOR MAGNESIUM:
Pumpkin seeds, spinach, Swiss chard, amaranth, sunflower seeds, cashews, almonds, quinoa, tempeh, sweet potatoes, white potatoes, soybeans, millet, starchy beans (black, navy, pinto, kidney), artichoke hearts, peanuts, peanut butter, chickpeas (garbanzo beans), brown rice, whole-grain bread, sesame seeds, wheat germ, flaxseed.