Level2 Medical Guide to Low-Carb Eating
Dec. 20 2022
Guiding Principles for Eating Low Carb
A low-carbohydrate diet simply means limiting the amount of carbohydrates you eat and replacing it with foods that are naturally low in carbohydrates (or carbs). Making the switch to eating a low-carb diet is a great way to lower your blood glucose and in the long run, can help keep your glucose levels in a healthy range.
Carbohydrates are typically found in refined pastas, breads and sugary foods or drinks. It’s a major macronutrient made up of chains of sugar, a.k.a. glucose. So, when we eat foods containing carbohydrates, our body stores that extra sugar in our liver to use as fuel. What happens if we eat too many carbs? That excess glucose in the body turns into fat, spikes glucose, and leads to other complications.
As you read, you’ll learn more of the science behind carbs along with tips to lower your carb intake to lower your glucose.
Eat Whole Foods
When you’re choosing to eat whole foods, you’re not eating unprocessed foods, or foods that don’t already exist in nature. For instance, eggs are easily found in nature. Asparagus and eggplants naturally grow in the ground.
Cookies don’t grow on trees. Chickens don’t lay donuts.
When foods undergo processing, they tend to gain things like:
They lose things like:
- Healthy fats
- Vitamins and minerals
- Water content
Read Food Labels, if You Must
Unprocessed foods don’t come in packages with food labels. But it’s not always possible to avoid foods found in boxes, cans or packaged in the frozen food aisle. Reading food labels will help you determine the nutrient value of the food item and whether there are any ingredient/additives that you want to avoid.
Here are some tips for reading food labels.
- If produce is difficult to find, consider vegetables and fruits as an alternative.
- Frozen meats are also an alternative to fresh meats.
- Scan the label for hidden sugar. It may be listed under another name – like sucrose, high-fructose corn syrup, dextrose or rice syrup to name a few.
- Canned soups can be easy meals but review the carbohydrates.
- Avoid trans fats labelled as hydrogenated or partially hydrogenated oils.
- Check the total carbohydrates.
- Look for high-fiber foods with 3 or more grams of fiber per serving.
Learn What Spikes Your Blood Glucose
The glycemic index (GI) is a system that ranks foods that contain carbohydrates from 1-100 based on their effect on blood sugar. Foods lower on the GI index raise blood sugar more slowly, while foods with a high GI value can cause a rapid rise and fall of blood sugar. Generally, the more processed a food is, the more likely it raises blood sugar rapidly.
Aim for low to medium GI foods, which includes items like whole wheat bread, oatmeal (steel cut or rolled), whole grains, non-starchy veggies, meats, nuts and eggs. Food with a score of 70 or higher should be eaten sparingly and include foods like white rice, white bread, pasta and noodles, some fruits and potatoes as well as beverages such as juice, soda or beer. The glycemic index is a helpful guide to help you identify good nutritional choices.
Foods that contain little or no carbohydrates have little or no effect of raising the blood glucose.
You might also use a continuous glucose monitor (CGM)to see which foods and drinks spike your glucose. A CGM allows you to precisely monitor your blood glucose in response to the various foods you eat. The glycemic index will give you a sense of what spikes blood sugar for most people, but the CGM can give you personalized data that you can use to control your diet.
Know Your Macros
Macros, which is short for macronutrients, are essential parts of your diet.
All foods are composed of three basic macronutrients:
First, let’s discuss proteins, which should be about 10 – 35% of your total calories. Proteins are composed of building blocks called amino acids, which are essential nutrients, meaning that not eating enough of them can make you sick. Eating protein does not raise blood glucose (also called blood sugar), because it does not contain glucose.
Meat, such as beef, pork, lamb, chicken, turkey, fish and shellfish are all good sources of protein. Try to eat fewer processed meats like bacon, ham, salami, sausages, hot dogs, beef jerky and slices of deli meats. When cooking meat avoid breading it and frying it in oil – stick to baking, broiling, stewing and roasting.
Good vegetable sources of protein include spinach, asparagus, collard greens, arugula, lentils, edamame and lima beans.
Want to learn more about adding healthy protein to your diet? Watch this video.
Fats are composed of fatty acids, which are also essential nutrients. Many people were raised believing that fat was unhealthy, and that consuming fat would in fact, make you fat. More recent research has proven this is not true. In fact, healthy fat is an important part of a healthy diet. Eating fat does not raise blood glucose, since it contains no glucose.
Like the other macronutrients, some fats are healthier choices than others – specifically, natural fats (fats found in nature) like avocados, nuts, dairy fat, olive oil, coconut oil and fatty fish. Healthy fats give you energy and help you feel satisfied.
Heavily processed fats, like trans fats (which include margarine and frozen pizza) should be avoided. Trans fats can be tricky to spot but read the labels: If they say hydrogenated or partially hydrogenated oil, they contain trans fats and should be avoided.
Watch this video to get the skinny on fats.
Carbohydrates (carbs, for short) are chains of sugars, such as glucose, fructose or lactose. Carbs contain energy (calories), but no essential nutrients. It is possible to eat very few carbs and still be healthy, which is different from proteins or fats. Eating carbs containing glucose raises blood glucose quickly and substantially.
A typical American diet contains 200-300 grams of carbohydrates a day. To naturally lower blood glucose, Level2 recommends a low carbohydrate diet contains less than 100 grams per day, or a very low carb diet with less than 40 grams per day.
There are three general types of carbs:
Starch molecules are composed of hundreds of molecules of glucose, in branched or unbranched chains. Once eaten, the glucose molecules are quickly digested, leading to a very quick rise in blood glucose. Starches have a very high glycemic index, meaning that on average, they raise blood glucose more quickly than other foods.
Starches include (but are not limited to):
- Starchy vegetables: Potatoes, sweet potatoes, yams, corn, peas and lima beans.
- Legumes: dried beans, peas and lentils.
- Grains: wheat, oats, barley and rice.
- Products made from grains: breads and pastas, crackers, cereals, English muffins, cupcakes, donuts, tortillas, naan, noodles, rice noodles, cereal.
Table sugar (sucrose) is composed of one molecule of glucose linked to one molecule of fructose. High fructose corn syrup (HFCS) is enriched with about 60% fructose. The natural sugar in fruit is actually fructose.
Fructose does not raise blood glucose but has negative health consequences in high doses. Because of its unique metabolism, it is prone to causing fatty liver and insulin resistance. These added sweeteners, often present in prepared foods and drinks should be avoided as completely as possible.
The sugar in milk (lactose) is not associated with health problems, and also does not raise blood glucose.
Examples of sugars to avoid include:
- Table sugar
- Fruit and fruit juices, as well as foods that contain fruit juices such as jams, jellies, and fruit smoothies.
- Sweets and bakery products such as cakes with icing, pie, donuts, cookies and candy.
- Beverages with added sugars: regular sodas, fruit drinks, some sports drinks like Gatorade, lemonade, or tea.
- Condiments (sweetened with added sugars): barbecue sauce, ketchup, relish, salsa, teriyaki sauce, and salad dressings.
- Dairy: milk, ice cream, coconut milk, pudding and yogurts.
- Sugars added during processing
Be extra careful of sugar because it can go by many names. Always read labels and nutrition facts on the back of store-bought foods. Don’t be fooled by products that claim to be sugar-free, low sugar or no added sugars on the external packaging or advertising. Look at the “Ingredients” list where added sugars can be found under alternate names such as:
Table sugar or sucrose, brown sugar, molasses, honey, lactose, fructose, sorbitol, xylitol, glycol, glycerol, mannitol, agave nectar, sugar cane syrup, turbinado, maple sugar, high-fructose corn syrup, powdered or confectioner’s sugar, molasses, beet sugar.
Fiber is a part of the carbohydrate that cannot be digested. This means that the body does not absorb any of this carbohydrate. Fiber produces benefits by slowing down the absorption of other carbohydrates allowing the blood glucose to stabilize and rise more gently. Level2 encourages eating as much fiber as you like.
Refined grains, like white flour and white rice, often have most of their natural fiber (along with many nutrients) removed during processing. Eating more unrefined whole grains, such as steel cut oats, whole grain bread and brown rice is preferable to the refined versions. Good sources of fiber include:
- Fruits, especially berries
- Non-starchy vegetables
- Whole grains
Check out this video on simple vs. complex carbohydrates to learn more!
People with type 2 diabetes have too much glucose in the body and specifically, blood. To visually see how your body reacts to certain foods, check out this animation video. You’ll see that the excess glucose spills out from cells that are already filled with glucose and into the blood. However, if you reduce dietary carbohydrates, you can stop this from happening.
How Many Carbs Should I Eat?
At Level2, we recommend following a low-carb (<100 grams/day) or very low-carb diet (<40 grams/day) to manage your blood sugars. Your care team will work with you specifically to find the amount that’s right for you.
Remember: To lower your blood glucose, look for the sugar in your diet and get rid of it!
Eat plenty of:
- Leafy, non-starchy vegetables
- Fresh berries
- Whole milk yogurt
- Seeds: chia, pumpkin, flax, etc.
- Use your CGM to determine how your body responds to whole grains like oats, quinoa, rice*
Limit and/or avoid:
- Sugary drinks: Soda, sports drinks, etc.
- Fruit juice: While masquerading around as healthy, most have a similar effect to soda.
- White bread: Refined carbs in general are low in nutrients and high in their ability to disrupt blood sugar.
- Pastries, cookies and cakes
- Ice cream
- Candies and chocolates: If you need chocolate, 70% dark or more is best.
Food Guide for Lower Carb Meal Planning
The food lists below show the amount of carbohydrate within each food.
Zero Carbohydrate Foods
The foods below contain 0 grams of carbohydrate per serving.
- Meats – beef, pork, lamb
- Fish – salmon, sardines, tuna
- Shellfish – oysters, clams, scallops, shrimp, crab, lobster
- Poultry – chicken, cornish hen, duck, goose, turkey
- Fats – oils: canola, coconut, peanut, avocado, olive,
Zero Carb Beverages
- Sparkling water
- Black coffee
- Diet soda (but beware of diet soda — it can still raise your blood sugar).
Zero Carb Spices & Seasonings:
- Salt, Pepper Sugar-free Hot Sauces Mustard
- Spices – Oregano, Rosemary, Thyme, Basil, Chives, Dill, Cinnamon, Turmeric
- Powders – Chili, Curry, Garlic, Onion Powder
Very Low Carbohydrate Foods
Foods that contain less than 5 grams of carbohydrate per serving are considered very low carbohydrate foods.
|Food Item||1 Serving||Grams of Carbohydrate per Serving|
|Almond milk, unsweetened||1 cup||1|
|Artichoke||1 cup raw vegetables or ½ cup cooked||<5|
|Arugula||1 cup raw vegetables or ½ cup cooked||<5|
|Avocado||2 Tbsp (1 oz)||2|
|asparagus||1 cup raw vegetables or ½ cup cooked||<5|
|Bamboo shoots||1 cup raw vegetables or ½ cup cooked||<5|
|Bean sprouts||1 cup raw vegetables or ½ cup cooked||<5|
|Beets||1 cup raw vegetables or ½ cup cooked||<5|
|Bok choy||1 cup raw vegetables or ½ cup cooked||<5|
|Broccoli||1 cup raw vegetables or ½ cup cooked||<5|
|Brussel sprouts||1 cup raw vegetables or ½ cup cooked||<5|
|Cabbage||1 cup raw vegetables or ½ cup cooked||<5|
|Carrots||1 cup raw vegetables or ½ cup cooked||<5|
|Cauliflower||1 cup raw vegetables or ½ cup cooked||<5|
|Celery||1 cup raw vegetables or ½ cup cooked||<5|
|Collard greens||1 cup raw vegetables or ½ cup cooked||<5|
|Cucumber||1 cup raw vegetables or ½ cup cooked||<5|
|Daikon||1 cup raw vegetables or ½ cup cooked||<5|
|Eggplant||1 cup raw vegetables or ½ cup cooked||<5|
|Green beans||1 cup raw vegetables or ½ cup cooked||<5|
|Jicama||1 cup raw vegetables or ½ cup cooked||<5|
|Kale||1 cup raw vegetables or ½ cup cooked||<5|
|Kimchi||1 cup raw vegetables or ½ cup cooked||<5|
|Kohlrabi||1 cup raw vegetables or ½ cup cooked||<5|
|Leeks||1 cup raw vegetables or ½ cup cooked||<5|
|Lettuce||1 cup raw vegetables or ½ cup cooked||<5|
|Mushrooms||1 cup raw vegetables or ½ cup cooked||<5|
|Okra||1 cup raw vegetables or ½ cup cooked||<5|
|Olives, black||8 small/medium||1.5|
|Olives, green||10 large, 1.5 oz||1.5|
|Onions||1 cup raw vegetables or ½ cup cooked||<5|
|Pea Pods, Pea Shoots||1 cup raw vegetables or ½ cup cooked||<5|
|Peppers||1 cup raw vegetables or ½ cup cooked||<5|
|Pumpkin, sesame, or sunflower seeds||1 Tbsp||2|
|Radishes||1 cup raw vegetables or ½ cup cooked||<5|
|Romaine||1 cup raw vegetables or ½ cup cooked||<5|
|Rutabaga||1 cup raw vegetables or ½ cup cooked||<5|
|Seaweed||1 cup raw vegetables or ½ cup cooked||<5|
|Snow peas||1 cup raw vegetables or ½ cup cooked||<5|
|Spinach||1 cup raw vegetables or ½ cup cooked||<5|
|Squash (yellow squash, spaghetti squash)||1 cup raw vegetables or ½ cup cooked||<5|
|Tomatoes||1 cup raw vegetables or ½ cup cooked||<5|
|Turnips||1 cup raw vegetables or ½ cup cooked||<5|
|Zucchini||1 cup raw vegetables or ½ cup cooked||<5|
Low Carbohydrate Foods
Foods that contain 5-10 grams of carbohydrate per serving are considered low carbohydrate foods.
|Food Item||1 Serving||Grams of Carbohydrate per Serving|
|Almonds, whole||1 oz (24-28 medium)||5.5|
|Beef jerky||1 oz||10|
|Flaxseed||3 Tbsp, 1 oz||9|
|Peanut butter||2 Tbsp||6|
|Pistachios, shelled||¼ cup, 1 oz||8.5|
|Strawberries||½ cup (cut)||6|
Low Carb Food Swaps
Low carbohydrate wraps (<5 grams of net carbs)
“Cauliflower” pizza crust
“Lettuce” wraps (Boston bib lettuce and romaine hearts)
Cucumber or zucchini “sub sandwich”
Stuffed bell peppers
Tomatoes or portobello mushrooms as hamburger buns
Cauliflower or broccoli “rice” fresh or frozen
Zucchini or squash noodles (“zoodles”)
Cauliflower mashed potatoes
- Kale or Zucchini “chips”
- Seaweed Snacks
|Grams of Carbohydrates in Different Types of Foods||￼|
|Serving size (amount of food)||Grams of Carb|
|Apple||1 small, whole||15|
|Banana||1 large, whole||31|
|Grapes||17 small grapes||15|
|Pineapple||3/4 cup, diced||15|
|Tangerine||1 small, whole||12|
|Corn||1/2 cup, cooked||15|
|Peas||1/2 cup, cooked||15|
|Potato||1 large, white (baked)||63|
|Mashed potatoes||1 cup||30|
|Baked beans||1 cup||45|
|**Asparagus, artichoke, brussel sprouts, cauliflower, cabbage, carrots, broccoli, onions, spinach, peppers||**1 cup raw or 1/2 cup cooked||**5|
|Snap peas, celery, cucumbers, salad greens, zucchini, summer squash, eggplant, greens (collard, kale, mustard)|
|Breads and Grains|
|Regular bread||1 individual slice||15|
|Bagel||1 large, whole||48|
|Pita||1 large, whole||33|
|Flour tortilla||1 tortilla (6 in)||15|
|Pasta||1 cup, cooked||45|
|Rice||1 cup, cooked||45|
|Quinoa||1 cup, cooked||45|
|Grits or oatmeal||1 cup, cooked (plain)||30|
|Crackers & Snacks|
|Crackers||6 Ritz (round butter), or 6 saltines||15|
|Chips||15 med tortilla||15|
|Rice Cake||2 regular (plain)||15|
|Milk, 2%||1 cup||11|
|Yogurt, low fat||1 container (8 oz), plain||16|
|Almond or soy milk||2 cups, plain||15|
|Pudding||1/2 cup, chocolate||28|
|Coca Cola||1 can (12 oz)||38|
|Gatorade sports drink||1 bottle (20 oz)||36|
|Ginger ale||1 can (12 oz)||32|
|Ice cream||1 cup||32|
|Chocolate chip cookies||2 cookies, medium||18|
|Apple pie||1 slice (1/6, 8″ pie)||40|
- Lower Carb Recipes (from Level2) – See the Level2 App – Nutrition
- ADA Diabetes Food Hub – https://www.diabetesfoodhub.org/diabetic-diabetes-low-carb-recipes.html?prev_scroll=949
- Center for Disease Control (CDC) guide to Carb Counting
- CDC guide to Carb Choices https://www.cdc.gov/diabetes/managing/eat-well/diabetes-and-carbs/carbohydrate-choice-lists.html
For a summary of this material and the guiding principles of low-carb eating, visit this link.