Diabetes is a major public health concern in the United States. According to the American Diabetes Association, 34.2 million Americans (more than 10% of the population) have diabetes. Of these, 1.6 million have type 1 diabetes, while the majority have type 2 diabetes. Poorly managed diabetes can lead to a number of serious complications, and the condition is the seventh leading cause of death in the United States.
But what exactly is diabetes? As the Centers for Disease Control and Prevention explained, "If you have diabetes, your body either doesn’t make enough insulin or can’t use the insulin it makes as well as it should." Most of the food we eat is eventually broken down into the simple sugar, glucose. Insulin is a hormone produced by the pancreas that allows glucose to enter cells, where it can be used as fuel. If the pancreas doesn’t produce insulin (type 1 diabetes) or cells become resistant to the effects of insulin (type 2 diabetes), excess glucose can build up in the bloodstream, causing damage throughout the body over time.
There’s no cure for diabetes, but paying close attention to your diet can help you better control your blood glucose levels. This includes avoiding foods that quickly spike your blood sugar and, if you have type 2 diabetes, choosing foods that can improve insulin sensitivity so your cells are better able to use glucose.
Avoid: Rice crackers
When it comes to the ideal diet for diabetics, perhaps the biggest issue is avoiding foods that will rapidly spike your blood glucose levels. While it’s probably obvious that sugar-laden treats like cookies and cake aren’t the best options, other choices aren’t always so clear. Luckily, a tool called the glycemic index (GI) can help. As Harvard Health Publishing explained, "The glycemic index is a value assigned to foods based on how slowly or how quickly those foods cause increases in blood glucose levels." Pure glucose is used as a reference point, with a value of 100. While rice crackers and cakes may seem relatively harmless because of their low calorie count, they’re very high on the GI, scoring an 87.
High-glycemic foods have a score over 70, while medium-glycemic foods score 56 to 69. Anything with a GI score of 55 or less is considered a low-glycemic food. So where should diabetics’ meals fall on the GI? If you have diabetes, aim to eat foods that are on the low or medium parts of the scale. It’s important to note that the GI doesn’t indicate how many grams of carbs are in a particular food, just how quickly those carbs will spike your blood sugar. So it’s also important to monitor your overall carbohydrate intake (via Beyond Type 2).
If you’ve been diagnosed with diabetes, you may think you need to stay away from carb-rich grains altogether if you want to keep your blood sugar levels under control. But some grains are actually quite low on the glycemic index (GI), thanks to their high fiber content. Barley, for instance, has a GI score of only 28, putting it deep into the "low GI" range (via Harvard Health Publishing).
In addition to not spiking blood glucose levels, barley may also help improve insulin sensitivity. In a 2015 study published in The British Journal of Nutrition, researchers fed individuals either a breakfast of bread made from barley or a placebo for three days. After testing participants’ blood on day four, the study authors found that those who consumed the barley had markers for better glucose control and their insulin sensitivity had improved by 25%. The researchers hypothesized that these beneficial changes were due to barley’s high resistant starch content.
Resistant starch is similar to fiber in that humans can’t digest it. It does, however, serve as food for our gut microbiome, the billions of friendly bacteria living in our large intestine. The researchers noted that these bacteria may significantly affect our metabolic processes, including glucose and insulin regulation.
Avoid: White bread
When it comes to picking carb-heavy foods that won’t send your blood sugar skyrocketing, white bread is one of the worst options. According to the Harvard Health Publishing, white bread has a glycemic index (GI) score of 75, making it a high-glycemic food. But that doesn’t mean you have to give up bread altogether. Whole-wheat loaves are a safer bet; they have a GI score of between 56 and 59, putting them on the cusp between low- and medium-glycemic (via San Francisco Chronicle).
This is a pattern that shows up again and again with grains: The "whole" version has a significantly lower GI score than the refined or "white" version. That’s because whole grains retain the fiber-rich outer part of the seed, which slows down how quickly the food can be digested and thus how fast glucose can hit your bloodstream. Whole grains also contain more micronutrients like vitamins and minerals than their refined counterparts. Even if you’re following a gluten-free diet, there are plenty of whole-grain options to choose from. These include brown rice, sorghum, quinoa, amaranth, buckwheat, and millet (via Diabetes Canada).
Eat: Pinto beans
Beans, beans, the magical fruit! The more you eat the more you … have control you have over your blood sugar levels. It doesn’t rhyme, but it’s the truth. What makes pinto and other beans so magical when it comes to diabetes is their soluble fiber content. Soluble fiber is one of two main types of fiber. Unlike insoluble fiber, which moves through your intestines intact and helps add bulk to stools, soluble fiber attracts water as it moves along, creating a gel-like substance. This slows digestion down, which means blood glucose levels rise gradually rather than spiking after a meal (via MedlinePlus). A half-cup of cooked pinto beans contains an impressive 5.5 grams of soluble fiber. The same serving size of black beans offers 3.8, while kidney beans contain 2.9 (via the North Ottawa Wellness Foundation).
A 2014 study published in the Asia Pacific Journal of Clinical Nutrition found that individuals with diabetes who consumed 7.5 grams of soluble fiber (in this case from oats, not beans) saw significant improvements in their post-meal glucose and insulin levels. This was due largely to the fact that the soluble fiber slowed the rate at which food left participants’ stomachs. Soluble fiber may also reduce insulin resistance. A 2013 study published in The British Journal of Nutrition noted that women who ate the most soluble fiber were roughly half as likely to be insulin resistant when compared to those who ate the least amount of soluble fiber.
Avoid: Fruit juice
It almost goes without saying that sugar-laden soda isn’t a great choice for diabetics. And while fruit juice may seem like a healthier option, it’s almost as detrimental as soda when it comes to spiking blood glucose levels. That’s because, when you come right down to it, the "natural" sugar in fruit juice is still sugar. And there’s a lot of it packed into each glass.
As NPR reported, many popular juice brands have as much or even more sugar than sodas. Minute Maid 100% apple juice, for instance, has almost 66 grams of sugar per liter — on par with Mug root beer (66.9 g/L) and Pepsi (65.7 g/L). While some juices offer less sugar (Tropicana 100% orange juice has 28.3 g/L, for example), they still pack a significant punch.
Although fruit juice contains blood sugar-spiking glucose, it’s also high in fructose, another simple sugar. Fructose is processed by the liver and while it doesn’t spike blood sugar levels, it can overwhelm the liver if consumed in large amounts. This can cause liver damage and increase the likelihood of complications from type 2 diabetes. For diabetics, it’s best to choose whole fruit over fruit juice. The fiber in fruit slows down the rate at which fruit sugar enters your system. But if you really enjoy juice, consider switching to vegetable juice, which has significantly less sugar (via diabetes.co.uk).
If you’ve decided to ditch your daily glass of fruit juice for a whole fruit, apples are an excellent choice. According to Harvard Health Publishing, raw apples have a glycemic index (GI) score of 36, making them a low-glycemic food. What’s more, apples appear to possess special compounds that can benefit people with diabetes.
According to a 2016 study published in Nutrition & Metabolism, apples contain polyphenols that improve insulin sensitivity, at least in animals. In the experiment, rats given an apple polyphenol extract experienced a 45% increase in insulin sensitivity and the rate at which glucose was able to enter body cells. In addition, the researchers noted that the apple polyphenols seemed to work synergistically with insulin, enhancing its effects. The study authors concluded that these polyphenols are "a promising ingredient for inclusion in nutritional products [for humans] focused on the management of chronic diseases such as diabetes."
But what exactly are polyphenols? According to Healthline, they’re a group of compounds found in a variety of plant foods. They serve as antioxidants, fighting free-radical damage in the body, and may also have anti-inflammatory properties. More than 8,000 polyphenols have been identified, and they fall into four broad categories: flavonoids, phenolic acids, polyphenolic amides, and a final miscellaneous group. Apples are particularly rich in flavonoids.
It may seem like honey is a more diabetes-friendly sweetener than white sugar — after all, it’s made by bees and contains micronutrients. But if you look at honey’s score on the glycemic index (GI), it’s not much better than sucrose (regular table sugar). Honey has a GI score of 61, while table sugar has a score of 65, putting both in the moderately glycemic category (via Harvard Health Publishing).
This means eating honey will drive your blood sugar level up almost as quickly as eating regular sugar. This observation was confirmed in a study published in 2015 in The Journal of Nutrition. Over the course of three 14-day periods, participants consumed 50 grams a day of sucrose, honey, and then high-fructose corn syrup. When examining the individuals’ glucose levels, insulin levels, and biomarkers for insulin resistance, researchers found no difference between the three sweeteners.
WebMD notes that although honey does contain trace amounts of vitamins, minerals, and antioxidants, making calories from honey less "empty" than calories from regular sugar, these beneficial micronutrients are present in such small quantities that they’re unlikely to have a significant impact. However, not all experts agree. According to WebMD, "research shows that honey has anti-inflammatory and antioxidant qualities. That may be important for people with diabetes, who often have higher levels of inflammation in their bodies."
Drink: Green tea
If you’ve been diagnosed with type 2 diabetes and you’re trying to improve your body’s insulin sensitivity so that you can better manage your condition, drinking green tea could help.
According to a 2013 meta-analysis published in the American Journal of Clinical Nutrition, drinking green tea can significantly lower fasting glucose and insulin levels, as well as improve individuals’ hemoglobin A1C levels. (Hemoglobin A1C is a marker of how well your body has been regulating glucose over the last several months.) Another study, published in PLoS One in 2014, concluded that green tea extract significantly improved insulin sensitivity and increased levels of glucagon-like peptide 1 (GLP-1). GLP-1 is a substance secreted by special cells in the intestines that assists with glucose regulation.
But what makes green tea so special? According to a 2014 paper published in Integrative Medicine Research, the compound epigallocatechin gallate (EGCG) may deserve the credit. EGCG is a catechin, a type of polyphenol found in especially high quantities in green tea. The paper authors noted, however, that research on green tea’s benefits on diabetes has been mixed.
When it comes to breakfast options, doughnuts are doubly dangerous for those with diabetes. Not only are they high in sugar, but deep-fried doughnuts also contain trans fats. Artificial trans fats, in the form of partially hydrogenated vegetable oils, have been linked to a number of health conditions, including type 2 diabetes. All individuals, whether diabetic or not, should avoid trans fats.
Despite being banned by the Food and Drug Administration (FDA), trans fats still end up in a number of products, particularly deep-fried and packaged foods. In addition to doughnuts, major sources of trans fats in the American diet include margarine, cakes, pie crusts, cookies, biscuits, crackers, and frozen pizza (via the American Heart Association).
A 2005 study published in Metabolism illustrated why trans fats are so problematic when it comes to managing diabetes. The researchers concluded that "a single meal enriched with [trans fats] can significantly increase insulin resistance." This is especially true for individuals with particular genetic variations. An earlier study, conducted on monkeys and published in Obesity in 2007, found that long-term consumption of trans fats increased insulin resistance because the fats interfered with insulin receptors on cells.
Adding a little spice to your meals doesn’t just enhance their flavor — it may also help you better manage your diabetes. Cinnamon, in particular, has demonstrated some impressive benefits.
A 2012 meta-analysis published in Clinical Nutrition examined six previously published studies and found that consuming 1 to 6 grams per day of cinnamon had a significant impact on subjects’ glycemic control. Participants had lower fasting blood glucose levels and lower hemoglobin A1C scores. Another paper, published in 2010 in the Journal of Diabetes Science and Technology, noted that cinnamon increases insulin sensitivity and facilitates the transfer of glucose into cells, particularly muscle tissue. Additionally, a 2001 study published in the Journal of the American College of Nutrition concluded that a compound found in cinnamon called methylhydroxychalcone polymer (MHCP) mimicked the effects of insulin on a cellular level.
But don’t go wild, adding cinnamon to everything you eat. Cinnamon can lower your blood sugar levels too much, causing potentially life-threatening hypoglycemia. And cassia cinnamon (the cheaper, more widely available form of the spice) contains high amounts of coumarin, a compound that has been linked to liver damage, mouth sores, and an increased risk for certain types of cancer (via Healthline).
Avoid: The herb gymnema
If you have diabetes, you may have heard of or even used the herb gymnema. The plant is native to India and Africa and has been used for centuries in Ayurvedic medicine for a number of conditions, including diabetes. In fact, its name means "destroyer of sugar" in Hindi (via WebMD). Gymnema works by both reducing absorption of sugar in the intestines and boosting insulin levels.
While the herb may be beneficial, it shouldn’t be taken in conjunction with Metformin. Metformin is a popular drug used to manage type 2 diabetes. According to MedlinePlus, Metformin "decreases the amount of glucose you absorb from your food and the amount of glucose made by your liver. Metformin also increases your body’s response to insulin." It may seem like combining gymnema and Metformin would boost the effects of both, but the opposite is true.
According to a paper published in 2017 in Diabetology & Metabolic Syndrome, the combo may actually reduce the bioavailability of Metformin and increase blood glucose levels (at least in rats). If you’ve been prescribed Metformin, it’s important to let your doctor or pharmacist know what other medications, herbs, or supplements you’re taking.
Herbs and spices are particularly high in antioxidants, so using even just a pinch of these powerful superfoods while cooking can make a big difference. In a 2010 paper published in Nutrition Journal, researchers established the total antioxidant content of thousands of foods. Excluding non-food herbal and dietary supplements, culinary herbs and spices had the highest average antioxidant content of any food category tested. The paper’s authors found that, within the realm of herbs and spices, cloves are king. They contain an average of 277.3 mmol/100 g. For comparison, the next richest source of antioxidants in this category was dried mint, with an average of 116.4 mmol/100g.
But why are antioxidants so important for managing diabetes? According to research published by the Endocrine Society and reported on by ScienceDirect, a diet high in antioxidants improves insulin sensitivity and can work synergistically with the diabetes drug Metformin. Researchers divided participants into four groups, all of which ate a low-calorie Mediterranean diet. Members of group A simply ate the diet, while members of group B ate the diet and took Metformin. The diets of individuals in group C were enriched with 800 to 1,000 milligrams of antioxidants daily, while those in group D consumed the same amount of antioxidants but also took Metformin. Groups C and D saw the biggest decrease in insulin resistance, with group D performing even better than group C.
Avoid: Artificial sweeteners
Considering the negative impact sugar can have on diabetics’ ability to maintain healthy blood glucose levels, you might think that artificial sweeteners are a better option. After all, they provide sweetness without adding calories or carbs to a food. While many experts agree that artificial sweeteners are safe for diabetics, some research suggests otherwise.
According to a 2020 study published in the Journal of Family Medicine and Primary Care, artificial sweeteners may actually worsen insulin resistance. Although artificial sweeteners don’t actually contain glucose, their sweet taste tricks the body into thinking the sweeteners are sugar. This triggers the pancreas to secrete insulin to handle the glucose the body thinks is there. Over time, elevated insulin levels damage insulin receptors on cells, leading to insulin resistance.
The Food and Drug Administration (FDA) has approved a number of artificial sweeteners. Aspartame (Equal) is one popular option. It’s not heat-stable, however, and can’t be used in cooking and baking. Saccharin (Sweet ‘n Low), sucralose (Splenda), and stevia are other commonly consumed artificial sweeteners. It’s important to note that most artificial sweeteners are significantly sweeter than sugar, so only a small amount needs to be used in products. The sweetener neotame, for example, is 7,000 to 8,000 times sweeter than sugar (via Cleveland Clinic).
Drink: Apple cider vinegar (but with caution)
You may have heard of taking apple cider vinegar (ACV) as a way to boost metabolism, but did you know it may also help individuals with diabetes better manage their condition?
One 2004 study published in Diabetes Care found that 20 grams of ACV improved insulin sensitivity by 34% among insulin-resistant participants. But what makes ACV useful for diabetes management? According to a 2014 paper published in Nutrition Review, ACV may work by promoting delayed stomach emptying after meals and delayed absorption of sugar in the intestines, suppressing the liver’s ability to make glucose, increasing glucose utilization by cells, and facilitating insulin secretion by the pancreas. The authors cautioned, however, that while ACV may have some promise as a complementary treatment for diabetes, more research is needed.
If you decide to use ACV as a way to help manage your diabetes, be careful. Vinegar is a strong acid and should always be diluted in a lot of water. Drinking too much or undiluted ACV can have a number of nasty side effects, including digestive upset, erosion of tooth enamel, bone mineral loss, and burns in the esophagus (via Healthline).