There is strong evidence that eating fewer carbohydrates helps improve blood sugars. This makes sense intuitively: carbohydrates are broken down by the body into sugar, directly leading to high blood sugars. Eat fewer carbohydrates and you will typically end up with less sugar in your blood.
For those with type 2 diabetes or are newly diagnosed with type 1, fewer carbohydrates mean that your body’s natural insulin production will have an easier time processing your blood sugars. If you take insulin, you will have a much easier time taking the appropriate amount of insulin.
Before you start a low-carbohydrate diet, talk with your healthcare provider. If you are taking blood sugar-lowering medications, then eating fewer carbohydrates without lowering your medication dosage may cause dangerous low blood sugars.
There are studies that show that people with diabetes can achieve success on both low-carbohydrate and high-carbohydrate diets. Those pursuing high-carb diets are often primarily eating more vegetarian or vegan diets that are high in complex carbohydrates and fiber. They are also frequently athletes who burn large amounts of sugar during exercise. We will look at other dietary approaches in a future article.
If you would like to dive into the research on low-carb diets for diabetes, please skip to the last section in this article.
Also, be sure to read Key Facts About Carbohydrates Everyone with Diabetes Should Know.
What Is a Low-Carb Diet?
There are many different ways to define and follow a low-carb diet. In this article, we are generally looking at people who wish to eat fewer carbohydrates than they are currently eating.
There is no one way to follow a low-carb diet. Generally, people try different amounts of carbohydrates until they reach an amount per day that works for their energy, taste preferences and blood sugar levels. Some people with diabetes on a low-carb diet eat as few as 15 grams of carbohydrates per day while others may eat many times that.
A low-carb diet limits foods that are high in carbohydrate such as grains (breads, pasta, rice, tortillas) and sweets (cookies, cakes, sugary drinks, fruits) and starchy vegetables (potato, carrots, beets). Remember sugar, which is added to many foods found in the grocery store, is converted to glucose in the body.
Many people on a low-carb diet eat a wide variety of foods and simply replace or limit grains or starchy vegetables and fruits to small portions once or twice a day. They fill up on non-starchy vegetables, healthy fats, and protein sources instead.
Why Should You Follow a Low-Carb Diet?
In his book, Dr. Bernstein’s Diabetes Solution, he explains that when a person with type 1 diabetes limits carbohydrate amount, insulin intake is also reduced. He writes that each injection involves a varying degree of insulin absorption. The more carbohydrates you eat, the higher the variance of insulin absorption will be. He also notes that food manufacturers are able to list carb content on food labels within a 20% margin of error. The fewer carbohydrates we consume, the easier our blood sugars are to manage in most cases.
Why You Should Not Follow a Low-Carb Diet?
- If you have a problem with your kidneys, first talk to your healthcare provider before changing your diet.
- If you are unable to get support from a healthcare provider regarding the adjustment of your medication or insulin doses, be cautious about starting a low-carb diet. A low-carb diet should change your medication needs and could result in low blood sugar levels if the necessary adjustments aren’t properly made.
- If you have type 1 diabetes and don’t check your blood sugar enough or manage your blood sugar levels well, a very low-carb diet could give you nutritional ketones, which are harmless unless your blood sugar is elevated for too long in which case can cause you to be at risk for developing diabetes ketoacidosis(DKA), a potentially life-threatening condition.
- If you have a history of eating disorders, do not start a restrictive diet without support from your healthcare team.
Common Mistakes in a Low-Carb Diet
- Eating too few carbohydrates. The right amount of carbs for one person isn’t enough for another. This means you need to listen to your body when going low-carb. How are your blood sugar levels? How are your energy levels? Are you satisfied for the next few hours after eating? Try adding carbohydrates until you feel you have reached the right personal amount for you which also best support your blood sugar levels.
- Too few quality carbohydrates. If the only carbohydrates you consume come from nutritionally empty sources like sugary drinks or desserts then you may want to try swapping some of those sources out for quality carbohydrates like berries, beans, or brown rice.
- Not enough fiber. A healthy diet results in healthy digestion. Fiber is immensely good for you. In fact, a study linked fiber intake as one of the greatest influences for healthy aging and longevity. Eating mostly real, whole foods (listed below) will likely get you adequate fiber.
- Not adjusting insulin doses. If you take medication or insulin for diabetes, switching to a low-carb diet will probably require some adjustments. Work closely with a healthcare provider and check your blood sugar levels more often as you make small changes until you get to the right dose for your new carb intake.
- Eating too little fat. It is challenging to do both low-carb and low-fat because this means your total calorie intake will be very low. Don’t be afraid of healthy fats like avocado, extra virgin olive oil and extra virgin coconut oil.
- Too many artificial sweeteners. Adding too many artificial sweeteners does several things; it doesn’t allow your palate to adjust to non-sweet flavors, it can negatively impact your gut flora balance, and you may experience unwelcome side effects. The best thing is to limit artificial sweeteners and try to focus on stevia, erythritol and xylitol.
How Do I Know If a Low-Carb Diet Is Working?
To see how your diet is impacting your blood sugars, we recommend checking them strategically around your meals.
- Check your blood sugar. You need to know where you are starting. Write it down.
- Eat a food. Write down what you ate and how many carbohydrates it contains.
- Check your blood sugar after one hour. This shows how high your blood sugars will peak after eating the food. Be aware that if you eat a large meal or one very high in fat, it may take more than an hour for your blood sugars to peak. Fat slows down digestion.
- Check your blood sugar after two hours. If your body can process the amount of carbohydrates you ate, you should be back to where you started or little bit higher.
Using this approach, you can quickly figure out how many carbohydrates your body can handle in a meal.
How to Start a Low-Carb Diet
If you have diabetes, it is a good idea to get support from a healthcare provider. Lowering your carb intake may mean you need less of any diabetes medications, including insulin.
Check your blood sugar more frequently as you adjust to your new way of eating. Keeping a log book is a great idea and will help you manage your blood sugar levels and keep track of how you are reacting to your low-carb diet.
Before proceeding, download a copy of our Free Foods Grocery Guide. This is cheat sheet of foods that have a little to no carbs in a single serving.
Types of Low Carb Diets
How to Build Your Low-Carb Plate
A simple way to start getting the hang of low-carb eating is to learn how to build your plate.
First, make sure you have some kind of source of protein like grilled chicken or fish or ground beef. Then add a serving of low-carb vegetables like broccoli or add a leafy green salad. Then depending on how few carbs you plan on eating, add one more serving of something else:
- Very low-carb eaters may add something like a serving of nuts or olives–something that contains fat and very little carbs.
- Other low-carb eaters may avoid grains but add in a portion of a root vegetable like carrots or sweet potato, or they may add tomatoes, some lower-carb fruit, or some legumes.
- Still other low-carb eaters may choose to add a serving of whole grains. The best types are unprocessed like brown rice, quinoa, bulgar, barley, millet and sorghum. It helps to omit or limit processed or refined grains like white pasta, wheat bread, wheat or corn tortillas, and oatmeal.
The key is to try different quantities of different foods and check your blood sugar to see how it responds to the way you are eating. You also want to have enough energy and be satiated after a meal. Filling your plate with plenty of protein, healthy fat and fiber tend to make a very satisfying meal.
The first step many people use to reduce carbohydrates in their diets is to remove or limit sugary beverages. Before are drinks that can be enjoyed without added carbohydrates.
- unsweetened iced tea
- unsweetened herbal tea
- coffee with no added sugar (a little cream is ok)
- diet soda
- diet fruit drinks sweetened with splenda, stevia or other artificial sweeteners
- sparkling water (including the no sugar, artificially flavored kind)
- wine (the drier the better)
A Tip for Switching to Low-Sugar Beverages
If you are struggling to lower added sugar in your beverages, it can be very helpful to gradually lower the amount of sugar you add. For example, if you add two teaspoons of sugar to your coffee each morning, try reducing that amount every few days by a tiny bit. It may be slow going but after a few months your taste buds will have adapted to either a very small amount of sugar in your coffee or possible none at all. This can also be done with iced tea. You can mix regular iced tea with unsweetened iced tea and gradually add more unsweetened than sweetened iced tea.
Beverages to Avoid
- regular soda
- juice (unless it consists of purely green vegetables, all juices are full of carbs)
- sweet tea
- coffee with added sugar and milk
- milk (a glass of milk contains about 11 grams of carbohydrates)
- energy drinks with added sugar
- cocktail drinks with added sugar from sweet liquors and juices
There are many drinks available now that use Stevia or other artificial sweeteners. These are advised to be used in moderation because some are known to raise blood sugar levels if a large quantity is consumed. For example, diet sodas may contain a small amount of sugar. The FDA allows manufacturers to round down to zero when they list the amount of sugar or carbohydrates on the can or bottle. If you drink these drinks in large amounts each day however, the amount of total carbs might impact your blood sugar levels without your awareness.
A large portion of a healthy diet involves eating vegetables for their fiber, water, and nutritional content. Non-starchy vegetables offer a great deal of variety while minimally impacting blood sugar levels.
The following are excellent choices to add to your daily diet and do not contain much of a carbohydrate load (meaning they don’t raise your blood sugar at all or very much).
When comparing options, please note the serving sizes. In most cases, it is per one cup. However, because nuts are denser, those are listed as per 1/2 cup. If you are comparing foods, make sure you take time to think about how much you are going to eat. For example, a one cup serving of fruit is going to be far more filling than a one cup serving of lettuce. It probably makes more sense to compare two cups of lettuce to a 1/2 cup of berries.
- asparagus (5g of carbs per cup)
- bell peppers (4.3 of carbs per cup)
- broccoli (6g of carbs per cup)
- Brussels sprouts (8g of carbs per cup)
- cabbage (5g of carbs per cup)
- cauliflower (5g of carbs per cup)
- celery (3g of carbs per cup)
- cucumber (2.6g of carbs per cup)
- eggplant (4.8g of carbs per cup)
- green beans (7g of carbs per cup) – technically a legume
- green peas (21g) / snow peas (7.4g) / sugar snap peas (7.4g) – technically a legume
- hot peppers: jalepeño (6g), poblano (17g per pepper), serrano (7g)
- leafy green vegetables: lettuce (2.1g), spinach (1.1g), collard greens (2g), beet greens (1.7g), kale (6.5g), swiss chard (1.3g), arugula (0.8g)
- mushrooms (2.3g of carbs per cup)
- olives (6g of carbs per 100 grams)
- radish (3.9g of carbs per cup)
- sprouts: alfalfa (0.7g), watercress (0.4g), broccoli sprouts
- zucchini (3.9g of carbs per cup)
Watch your intake of the following root vegetables which contain higher amounts of carbohydrates shown in net carbs:
- potato (23g of carbs per cup)
- sweet potato (23g of carbs per cup)
- carrots (9g of carbs per cup)
- rutabaga (8g of carbs per cup)
- yams (36g of carbs per cup)
- turnips (6g of carbs per cup)
- onions (14g of carbs per cup)
- beets (9g of carbs per cup)
- parsnips (17.5g of carbs per cup)
- celeriac (celery root) (8g of carbs per cup)
Fruits contain carbohydrates due to their natural sugar. Some fruits have a higher amount of carbohydrate than others. Here are great options for a low-carb diet:
- watermelon (10g of carbs per cup)
- strawberries (13g of carbs per cup)
- cantaloupe (13g of carbs per cup)
- avocado (13g of carbs per cup)
- blackberries (14g of carbs per cup)
- raspberries (15g of carbs per cup)
- honeydew (16g of carbs per cup)
- blueberries (20g of carbs per cup)
- coconut (12g of carbs per cup)
Legumes are a great source of fiber and protein. Grams of fiber are generally subtracted from the total carbohydrates of a food when calculating carbohydrate intake. For example, if a serving of black beans contains 30 grams of carbohydrates but 5 grams of fiber, the total amount of carbs that generally impact blood sugar, called “net carbs” is lowered to 25 grams.
Legumes contain plenty of carbohydrates but also plenty of fiber and water. Watch your servings of legumes to maintain your low-carb diet.
- green peas (21g of carbs per cup)
- lentils (40g of carbs per cup)
- black beans (45g of carbs per cup)
- pinto beans (43g of carbs per cup)
- navy beans (47g of carbs per cup)
- garbanzo beans (20g of carbs per cup)
- edamame soybean (12g of carbs per cup)
A great way to add healthy carbohydrates is to add ones with fiber and water like vegetables and legumes. Play around with serving sizes and take note how your blood sugar levels react.
Try incorporating legumes with healthy meat dishes or vegetables to reduce the amount you use.
Nuts and Seeds
Nuts and seeds like those below tend to be low in carbohydrate and can be used as snacks or to enhance any number of dishes. We are showing the amount of carbs per half cup.
- almonds and almond butter (10g of carbs per half cup)
- Brazil nuts (8g of carbs per half cup)
- cashews and cashew butter (19g of carbs per half cup of nuts)
- chestnuts (37g of carbs per half cup)
- coconut (6g of carbs per half cup)
- flax seeds (25g of carbs per half cup)
- hazelnuts (11.5g of carbs per half cup)
- macadamia nuts (9.5g of carbs per half cup)
- peanuts and peanut butter (12g of carbs per half cup)
- pecans (7g of carbs per half cup)
- pine nuts (9g of carbs per half cup)
- pistachios (17g of carbs per half cup)
- pumpkin Seeds (17g of carbs per half cup)
- sesame seeds and sesame butter (17g of carbs per half cup of seeds)
- sunflower Seeds and sunflower butter (14g of carbs per half cup)
- walnuts (5.5g of carbs per half cup)
Try using nuts and seeds in salads, yogurt and in other dishes to add healthy fats and fiber and protein. Try a low-carb snack consisting of mixed nuts.
An integral part of a low-carb diet is the consumption of animal protein (or tofu can be used in vegan low-carb diets). These foods help with healthy fats, satiety and adequate protein intake. Low-carb eaters often create their meals around one of these sources of protein. These foods tend to be very low in carbohydrate.
- beef Jerky
- cold cuts like ham, turkey, salami
- organ meats
These are all very low in carbs and work well in a low carb diet to help add flavor and calories to foods.
- cream cheese
- yogurt (non-sweetened)
- whipping or heavy cream
- sour cream
- kefir (non-sweetened)
- brown rice
- steel cut oats
- whole cornmeal or corn kernels
- quinoa (technically a seed)
Be aware that processed grains will often have a higher impact on blood sugars do to a lack of fiber (removed by the highly refined process) These include:
- white bread
- white rice
- degermed cornmeal
- instant rolled oats
Be careful about portion sizes when eating grains. Try having an open faced sandwich instead of the typical two slice of bread sandwich. Mix pasta or rice with vegetables and grilled chicken or salmon. Have corn mixed with low-carb vegetables. Look for low-carb tortillas and limit to one or two at a time.
There are no truly low-carb grains so you need to be careful with any grains and check your blood sugar levels to see how they respond to different serving sizes of these foods. Test out recipes that use coconut and almond flour as they contain fewer carbohydrates.
Low-Carb Breakfast Recipes
- Gluten-Free, Low-Carb, Multi-Grain Breakfast Muffins
- Strawberry Almond Milk Chia Seed Pudding
- Low-Carb Cottage Cheese Pancakes
- Bacon Breakfast Enchiladas
- Tomato and Fresh Mozzarella Omelet
- Bacon, Egg, and Cheese Muffins
- Avocado Breakfast Pizza
- Cookie PB Dough Protein Shake
- Pumpkin Chia Seed Pudding
- Chia Seed Pudding Recipe
- Spinach and Bacon Quiche
- Lower Carb Strawberry Smoothie
- 4 Ingredient Flourless Vanilla Ricotta Pancakes
Low-Carb Lunch or Dinner Recipes
- Spinach Alfredo Pizza
- Salsa Chicken
- Lemon Dill Turkey Burgers
- 5 Ingredient Spinach-Stuffed Salmon
- Low-Carb Cheesy Spinach-Stuffed Meatloaf
- Low-Carb Buffalo Ranch Chicken Salad Wraps
- Chicken Bella
- Pollo Borracho
- Spaghetti Squash with Primavera Sauce
- Roasted Garlic Chicken Soup
- Quinoa Salad Stuffed Avocados
- Open Faced Rotisserie Chicken Sandwiches
- Coconut Flour Chicken Tenders
- Deconstructed Spaghetti Squash Carbonara
- Jamaica Pork Tenderloin
- Portabello and Spinach Quesadilla
- Best Homemade Buffalo Chicken Wings
Low-Carb Dessert Recipes
- Low-Carb Chocolate Mint Grasshopper Brownies
- Chewy Chocolate Keto Fudge Brownie Bites
- Low-Carb Grain-Free Single Serve Brownies
- Keto Coconut Macaroons
- Low-Carb Blender Sherbet
- Homemade Thin Mints (Low-Carb and Gluten Free)
- Cinnamon Twists
- Red Velvet Donuts and Cupcakes
- Healthy Low-Carb Frozen Coffee Drink
- Coconut Banana Cream Pie
- Brown Butter Coconut Cookies
- Low-Carb Pumpkin Cheesecake Mousse
Low-Carb Snack Ideas
- raw vegetables with hummus (or other dip)
- handful of nuts
- boiled egg or deviled egg
- beef jerky
- can of tuna, mackerel, sardines, or anchovies
- string cheese
- celery with almond or peanut butter
- handful of berries
- coconut chips
Condiments, Herbs and Spices
Beware of added sauces and flavorings to your food. Ketchup, barbecue and soy sauce often have a high amount of added sugar and can throw off what is otherwise a low-carb meal.
So take care what you top your food with and focus your flavor adding efforts on herbs and spices. Herbs and spices add not only great taste but wonderful nutritional and health benefits to your diet. Plus, they can help you adjust to less sugar.
Help Starting a Low-Carb Diet
Check out the Food & Diet section of the Diabetes Daily Forums.
Research on Low-Carb Diabetes Diets
The American Diabetes Association’s Nutrition Therapy Recommendations for the Management of Adults With Diabetes are developed by a team of medical professionals that review all of the major diabetes-related research and turn them into guidelines.
Here’s what the guidelines have to say on low-carb diets. Please note that the letters in parenthesis describe how strong the evidence is. “A” means the studies were randomized and well controlled. “C” means that the evidence comes from poorly controlled studies or conflicts with others tudies. For more explanation, see Table 1 in the Standards of Medical Care in Diabetes.
- Evidence is inconclusive for an ideal amount of carbohydrate intake for people with diabetes. Therefore, collaborative goals should be developed with the individual with diabetes. (C)
- The amount of carbohydrates and available insulin may be the most important factor influencing glycemic response after eating and should be considered when developing the eating plan. (A)
- Monitoring carbohydrate intake, whether by carbohydrate counting or experience-based estimation, remains a key strategy in achieving glycemic control. (B)
The Guidelines continue:
Evidence is insufficient to support one specific amount of carbohydrate intake for all people with diabetes. Collaborative goals should be developed with each person with diabetes. Some published studies comparing lower levels of carbohydrate intake (ranging from 21 g daily up to 40% of daily energy intake) to higher carbohydrate intake levels indicated improved markers of glycemic control and insulin sensitivity with lower carbohydrate intakes. Four [randomized controlled trials] indicated no significant difference in glycemic markers with a lower-carbohydrate diet compared with higher carbohydrate intake levels. Many of these studies were small, were of short duration, and/or had low retention rates.
Some studies comparing lower levels of carbohydrate intake to higher carbohydrate intake levels revealed improvements in serum lipid/lipoprotein measures, including improved triglycerides, VLDL triglyceride, and VLDL cholesterol, total cholesterol, and HDL cholesterol levels. A few studies found no significant difference in lipids and lipoproteins with a lower-carbohydrate diet compared with higher carbohydrate intake levels. It should be noted that these studies had low retention rates, which may lead to loss of statistical power and biased results. In many of the reviewed studies, weight loss occurred, confounding the interpretation of results from manipulation of macronutrient content.
Despite the inconclusive results of the studies evaluating the effect of differing percentages of carbohydrates in people with diabetes, monitoring carbohydrate amounts is a useful strategy for improving postprandial glucose control. Evidence exists that both the quantity and type of carbohydrate in a food influence blood glucose level, and total amount of carbohydrate eaten is the primary predictor of glycemic response. In addition, lower A1C occurred in the Diabetes Control and Complications Trial (DCCT) intensive-treatment group and the Dose Adjustment For Normal Eating (DAFNE) trial participants who received nutrition therapy that focused on the adjustment of insulin doses based on variations in carbohydrate intake and physical activity.
As for the general U.S. population, carbohydrate intake from vegetables, fruits, whole grains, legumes, and milk should be encouraged over other sources of carbohydrates, or sources with added fats, sugars, or sodium, in order to improve overall nutrient intake.
The guidelines go into much greater details. You can read them here. They include extensive footnotes so that you can see the studies that support each claim made.
Source: Diabetes Daily