10 of the worst foods for blood sugar—according to CGM data - Levels (2023)

These foods produced some of the worst blood sugar responses among Levels members. Here's how you can make them healthier.

Levels members log what they eat in the Levels app to see how their body responds. The app pulls in data from a continuous glucose monitor to measure blood sugar, then analyzes several aspects of the glucose response (rise from baseline, height of the peak, recovery time back to baseline) along with the activity around that meal that may impact glucose (say, a post-meal walk). Together, that yields the Zone Score, a simple 1-10 rating for that meal, 10 being the best.

In aggregate, those thousands of logs tell a story about some of the worst foods for our metabolic health; foods that frequently caused a significant glucose response had the lowest overall Zone Scores.

Some foods on the list, such as donuts, will likely not surprise anyone. But you may not expect to see something like sushi—fish, after all, is a protein, unlikely to spike blood sugar. However, the white rice under the fish is a processed starch that can cause a glucose rise in many people. Another surprise? Grapes made the list. Whole fruit is better than processed food (or juice) for sure, but some fruits contain more sugar than others.

“Continuous glucose monitors are rare among people without diagnosed metabolic impairment. But it’s exciting to see the things that data can reveal as this kind of bio-monitoring expands to broader populations.”

This list has some caveats. First, people rarely log foods alone, and meal order and composition affect the glucose response. So a dinner log might consist of chicken, broccoli, and bread. The first two are unlikely to spike one’s glucose, but the bread almost certainly will. If you eat the protein first, it can blunt the bread’s impact. Had a glass of wine? That can further confound the results.

So we focused on entries where the listed food was the only thing in the log. That’s why it’s heavy on foods often eaten alone, like pizza or dessert, or just categories, such as Thai.

Second, this is by no means a definitive list of foods that can cause a blood sugar rise or negatively impact your metabolic health. That would include just about anything with added sugar, high-carb foods like bread, and most processed foods.

(Video) The WORST Foods To Eat If You're DIABETIC...and What To Eat Instead

This is, however, the first time we’ve had data-backed confirmation that these foods are more likely to cause a negative metabolic response. Continuous glucose monitors are rare among people without diagnosed metabolic impairment. But it’s exciting to see the things that data can reveal as this kind of bio-monitoring expands to broader populations.

Five Surprising Foods That Spiked Blood Sugar—and How to Make Them Healthier

1. Grapes

Why it Likely Scored Low: Many fruits are high in sugar and will produce blood sugar spikes (although whole fruit is always better than juice). Grapes have 15g–20g of sugar per cup, and though they have a low glycemic index, many people find they raise glucose levels sharply.

How to Make it Healthier: Eat fewer grapes, pair them with fat or protein, or swap them for berries like strawberries, raspberries, or blackberries, which have around half the sugar.

2. Oatmeal

Why It Likely Scored Low: Often considered a go-to healthy breakfast, oatmeal surprises many Levels members as a glucose spiker. Heavily processed “instant” or rolled varieties break down more quickly, leading to a sharp blood sugar rise, and flavored varieties often contain added sweeteners.

How to Make it Healthier: Swap your morning bowl for a healthy smoothie topped with hearty toppings like hemp seeds, almond butter, chopped nuts, and chia. If you just can’t give up oatmeal, aim for steel-cut oats or groats, and pair with healthy fat and protein like walnuts, almond butter, and chia. We also love swapping oatmeal for grain-free granolas or a warm chia pudding.

Tasty ideas for a low-carb breakfast

Don’t start your day with a blood-sugar spike and energy-draining crash. Try these delicious—and glucose-friendly—breakfast options instead.

Read the Article

(Video) Top 10 Worst Foods For Blood Sugar +How It Impacts Women's Hormone & Metabolism with Dr Casey Means

3. Sushi

Why It Likely Scored Low: Sticky white rice is refined and high in starch. Soy sauce also frequently contains sugar.

How to Make it Healthier: Order sashimi with no rice, and don’t drown it in soy sauce. Or, try cauliflower rice sushi, which is starting to appear at restaurants and is easy to make.

4. Acai Bowl

Why It Likely Scored Low: Acai berries are low in sugar (just 2g or 3g per 100g) and loaded with antioxidants, but they have a slight bitter taste, so commercial bowls tend to mix in sweeter fruits like bananas or mangos, sweeteners like honey, or sweetened nut milks, shooting the sugar through the roof. Blended bowls are even worse, reducing some of the fiber that can slow glucose absorption.

How to Make it Healthier: Mix your own at home, or go off-menu when you order. Reduce the sweeteners, add low-sugar fruits like berries, lemon juice or coconut, and mix in unsweetened milk. Even better, add veggies like spinach, and healthy fats like chia or flaxseeds.

5. Pho and Ramen

Why It Likely Scored Low: Though these are two distinct foods, the spike is most likely from the same culprit: noodles. (Note that we also see food logs for broad cuisines like Thai and Chinese food, but there too the glucose offender is a particular ingredient such as white rice or a sweet sauce. There are many, many healthy Thai and Chinese menu options.) Noodles (even rice noodles) are a processed food made with refined grains that tends to spike many people.

How to Make it Healthier: Look for dishes without noodles, or if you’re cooking at home, swap in alternative pastas made with konjac root or vegetables. Many pho and ramen restaurants now offer vegan options with spinach noodles, zucchini noodles, or tofu noodles. Also, avoid any sugary sauces or glazes.

(Video) Level Up Your CGM Data - Levels CGM Analysis

Five Less-Surprising Blood-Sugar Bombs—and Some Healthier Alternatives

6. Chik-Fil-A and McDonald’s

Why It Likely Scored Low: Most items on these menus would fall under the ultra-processed food category. That means they likely have added sugars, refined carbohydrates with little fiber, and poor nutrient content, all of which can cause a rise in blood sugar. A Chik-Fil-A sandwich has sugar listed three times in its ingredient list and five types of flour! And these meals often come with a sugary drink like orange juice or soda.

What are processed foods and why are they so bad for metabolic health?

Here’s what “processed” actually means, how these foods impact your metabolic health, and how to avoid the worst of them in the grocery aisles

Read the Article

How to Make it Healthier: Ideally, skip the fast-food joints altogether. If you’re stuck at one, look for whole foods without additives, like a salad with chicken breast (skip sugary dressings or croutons) or a burrito bowl without rice.

(Video) Ep. 80 - Top Ten Foods that Spike Blood Sugar | How NOT to break your fast | Emotional ties to...

7. Donut

Why It Likely Scored Low: Whether a dense old-fashioned or fluffy glazed, donuts are a blood-sugar double-whammy. First, the dough is made with refined white flour, which strips grains of many of their nutrients and their microbiome-friendly fiber. This allows your body to absorb the carbohydrates more quickly, potentially spiking your blood sugar. Second, donuts can contain several grams of added sugar, even without glaze or frosting (which is often basically pure sugar).

How to Make it Healthier: To make any baked good more glucose friendly, swap refined flour for a nut flour, like almond, and use a natural alternative sweetener like allulose or monk fruit instead of sugar. At Levels, we love glonuts and these lightly sweetened almond flour donuts from Minimalist Baker.

8. Pizza

Why It Likely Scored Low: Pizza crust is another refined flour dough and often includes sugar. The tomato sauce and even processed meats like pepperoni and sausage may also contain hidden sugars.

How to Make it Healthier: Cauliflower pizza crust is now easy to find in the frozen section and even on some menus. For toppings, stick with healthy veggies and unprocessed, clean proteins like pastured raised chicken, grass-fed, grass-finished beef or pork, or tofu.

9. Pancakes

Why It Likely Scored Low: Pancake batter contains ultra-refined white flour and also typically contains sugar. Top it with maple syrup, and it’s a trifecta of glucose spiking. While maple syrup is a natural sweetener that does have some minerals, it’s still ⅔ sucrose.

How to Make it Healthier: Fortunately, there are so many delicious pancake mixes that are grain- and sugar-free. We like Pamela’s pancake and waffle mix made with coconut flour, pecan flour, walnut flour, and cassava flour (note: cassava does spike some people), and Birch Bender’s Keto pancake mix, made with tiger nut flour, almond flour, coconut flour, and cassava.

10. Cereal

Why It Likely Scored Low: Even the brands advertised as “healthy” (we’re looking at you, Cheerios) tend to list sugar as one of the first ingredients. Don’t be fooled by phrases like “whole grain”—cereals are processed foods that will likely raise blood sugar.

How to Make it Healthier: Keto-friendly cereals like Magic Spoon swap in alternative sweeteners and may lower the glucose response for some people. Or better yet, make your own grain-free granola or buy some at the store (we have tried this brand mixed with unsweetened cashew milk and have had minimal spike).


Which food has the biggest impact on blood sugar? ›

Carbohydrates. Carbohydrates are the body's preferred source of energy; in fact, our brains only use glucose, a carbohydrate, for energy. 100% of carbohydrate sources consumed turn into glucose in the bloodstream, making carbohydrates the food group that impacts your blood sugar the most.

What vegetable causes havoc on your blood sugar? ›

Starchy vegetables—like beets, carrots, and jicama—contain higher amounts of carbs, and because of this, can raise blood sugar much faster than non-starchy veggies.

What foods raise your a1c? ›

Rice, bread, noodles, potatoes, beans, vegetables, mushrooms, seaweeds, fruits, sugar etc. Meats, fish and shellfish, eggs, soybeans and soy products, milk and dairy products etc. Carbohydrates do raise blood sugar levels quickly.

What foods should diabetics absolutely avoid? ›

Therefore, it's important to avoid the foods and drinks listed below.
  • Sugar-sweetened beverages. ...
  • Trans fats. ...
  • White bread, rice, and pasta. ...
  • Fruit-flavored yogurt. ...
  • Sweetened breakfast cereals. ...
  • Flavored coffee drinks. ...
  • Honey, agave nectar, and maple syrup. ...
  • Dried fruit.

What is the number 1 vegetable to avoid? ›

Cruciferous Vegetables

Vegetables that belong to the cabbage family such as cauliflower, Brussels, broccoli, and sprouts should never be consumed raw. These vegetables contain sugar that is difficult to digest. Eating these vegetables raw may lead to a number of gastronomical problems.

Does cheese raise blood sugars? ›

Will cheese affect blood sugar levels? Cheese has a low glycemic index (GI), meaning that it releases glucose slowly and will not trigger significant blood glucose spikes.

What is the one food that lowers blood sugar? ›

Go nuts. That's right—go ahead and snack on almonds, cashews or even pistachios. In one study, pregnant people at-risk for gestational diabetes had lower blood sugar after eating pistachios versus the group that consumed whole wheat bread.

Do cucumbers raise blood sugar? ›

Cucumbers are not known to spike blood sugar levels due to the minimal amounts of sugar and low-calorie count. In addition, they are not energy dense and have a low glycemic index and a high percentage of water. These properties make cucumber a good option for minimising their sugar intake.

What are six foods that cause diabetes? ›

You should limit (or at least minimise) your consumption of the following six types of foods:
  1. Sugary Foods. ...
  2. White Rice, Bread, and Flour. ...
  3. Full-Fat Dairy products. ...
  4. Fatty Cuts of Meat. ...
  5. Packaged Snacks and Baked Goods. ...
  6. Fried Foods.
9 Apr 2015

Which vegetables should be avoided in diabetes? ›

People living with diabetes should look to avoid vegetables with a high GI rating, as the body absorbs blood sugar from those foods much quicker compared with low-GI foods. This includes artichokes, asparagus, broccoli, celery, cauliflower, eggplant/aubergine, green beans, lettuce, peppers, snow peas and spinach.”

What fruits to avoid if you are diabetic? ›

Diabetics should avoid fruits with a high GI or eat them in moderation so that their blood sugar levels do not spike abruptly. Pineapple, watermelon, mango, lychee, and banana have a high GI, so these are the worst fruits if you are diabetic.

Are carrots OK for diabetics? ›

Carrots can be a safe choice if you have diabetes and are watching your blood sugar levels. They're also non-starchy vegetables. So you can even enjoy small amounts of carrots if you're following the ketogenic, or keto, diet.

Does coffee raise blood sugar? ›

For most young, healthy adults, caffeine doesn't appear to noticeably affect blood sugar (glucose) levels, and having up to 400 milligrams a day appears to be safe.

What is the fastest way to drop A1C? ›

7 Ways to Improve Your A1C
  1. Exercise. Physical activity helps your body use insulin more efficiently, so it can better process the glucose in your blood. ...
  2. Eat Right. ...
  3. Take Medications as Prescribed. ...
  4. Manage Your Stress. ...
  5. Stick to a Schedule. ...
  6. Drink in Moderation. ...
  7. Monitor Your Numbers.

Do eggs raise A1C? ›

They found that eating 12 eggs per week had no adverse effects on body weight, cholesterol level, blood sugar level or glycated hemoglobin (or A1C, which measures blood sugar levels over a few months).

Do apples raise A1C? ›

While some forms of fruit, like juice, can be bad for diabetes, whole fruits like berries, citrus, apricots, and yes, even apples — can be good for your A1C and overall health, fighting inflammation, normalizing your blood pressure, and more.

Is oatmeal good for diabetics? ›

Oatmeal offers a host of health benefits and can be a great go-to food for those with diabetes, as long as the portion is controlled. One cup of cooked oatmeal contains approximately 30 grams of carbs, which can fit into a healthy meal plan for people with diabetes.

Does tomato raise blood sugar? ›

Tomatoes and Type 2 Diabetes

In essence, the low carbohydrate content in fresh tomatoes suggests that these fruits shouldn't cause a drastic increase in blood sugar.

Can diabetics eat potatoes? ›

Potatoes are a versatile and delicious vegetable that can be enjoyed by everyone, including people with diabetes. However, because of their high carb content, you should limit portion sizes, always eat the skin, and choose low GI varieties, such as Carisma and Nicola.

What vegetables worsen blood sugar? ›

Starchy Vegetables, Which in Large Amounts Can Destabilize Blood Sugar. Oh, the poor potato — and, along with it, other starchy vegetables like peas and corn. These foods pack a greater quantity of carbs compared with nonstarchy vegetables like broccoli, cauliflower, cabbage, and lettuce.

What is the number 1 healthiest food in the world? ›

Lemons. Lemons have been widely regarded in the health industry as the world's healthiest food. The sour fruit is an alkalising powerfood; they have strong anti-inflammatory qualities and can even help to inhibit the growth of cancer cells.

What vegetable do doctors say to avoid? ›

Nightshade vegetables, like peppers, potatoes, and eggplant, are are controversial, because many claim they can cause inflammation, according to Cynthia Sass, a registered dietician. This can lead to some pretty serious complications down the line: heart disease, cancer, and diabetes, to name a few.

Do carrots raise blood sugar? ›

Both boiled and raw carrots have a low glycemic index score. This means that they are unlikely to trigger a blood sugar spike.

Is there any bread a diabetic can eat? ›

The American Diabetes Association recommends choosing whole grain bread or 100 percent whole wheat bread instead of white bread. White bread is made from highly processed white flour and added sugar. Here are some delicious and healthy breads to try: Joseph's Flax, Oat Bran and Wheat Pita Bread.

Does lemon water reduce blood sugar? ›

Lemon juice significantly lowered the mean blood glucose concentration peak by 30% (p < 0.01) and delayed it more than 35 min (78 vs. 41 min with water, p < 0.0001).

How fast can A1C drop in 3 months? ›

Remember what your A1C measures: your average blood sugars over the past three months. The good news is that if your A1C is on the high side, say, 10% or higher, it will likely start to drop within two to three months (in other words, the higher it is, the faster it comes down).

Does peanut butter lower blood sugar? ›

Peanuts and peanut butter have even been shown to help lessen the spike in blood sugar when paired with high-carbohydrate or high-GL foods. Peanuts and peanut butter are both low GI and GL foods, as they contain healthy oils, protein, and fiber that have a positive effect on blood sugar control.

Does sweet potato good for diabetes? ›

If you have diabetes, sweet potatoes are a safe option to add to your diet in moderation. Sweet potatoes are known to be high in fiber and have a low glycemic index, which results in a less immediate impact on blood glucose levels. This can help individuals with diabetes control their blood sugar.

Is celery good for diabetics? ›

Being a vegetable low in calories and sugar, celery is recommended by many physicians and nutritionists as a healthy snack for diabetics, as it can help regulate blood sugar.

Is Apple good for diabetics? ›

Apples are an excellent fruit to include in your diet if you have diabetes. Most dietary guidelines for people living with diabetes recommend a diet that includes fruits and vegetables (21). Fruits and vegetables are full of nutrients such as vitamins, minerals, fiber, and antioxidants.

Why is my blood sugar so high when I'm not eating any carbs? ›

So people reduce their carb intake, go on a low carbohydrate diet, and focus on eating healthy fats and (in many cases) too much protein. But what this solution crucially fails to address is insulin resistance, which is the true cause of those high blood glucose numbers.

Why does my blood sugar go up without eating? ›

Physical or emotional stress triggers the release of hormones that can cause high blood sugar levels. Menstrual periods and menopause also cause changes in the hormones that affect blood sugar levels. Regular blood sugar testing can uncover patterns. This can help you and your health care team control your diabetes.

Is honey Good For Diabetes? ›

Generally, there's no advantage to substituting honey for sugar in a diabetes eating plan. Both honey and sugar will affect your blood sugar level. Honey is sweeter than granulated sugar, so you might use a smaller amount of honey for sugar in some recipes.

Are tomatoes OK for diabetics? ›

Tomatoes are not high in sugar, and neither are carrots. Tomatoes, similar to carrots, are considered a non-starchy vegetable in meal planning for diabetes. This means that the amount of naturally occurring sugar is minimal in a serving.

Is cucumber good for diabetics? ›

Early trials suggest that cucumber is one of the most effective plants for not only reducing blood sugar levels but also lowering the risk of hypoglycemia during a blood sugar drop. For people with diabetes, cucumber may be a helpful addition to their diet to moderate blood sugar levels more effectively.

Which meat is best for diabetics? ›

Very Lean Meat Choices (0-1g fat/ounce and 35 calories)

Poultry: Chicken or turkey (white meat, no skin), Cornish hen (no skin). Fish: Fresh or frozen cod, flounder, haddock, halibut, trout, lox, tuna fresh or canned in water. Shellfish: Clams, crab, lobster, scallops, shrimp.

What 7 fruits should diabetics avoid? ›

High GI fruits diabetics should avoid
  • Bananas.
  • Oranges.
  • Mango.
  • Grapes.
  • Raisins.
  • Dates.
  • Pears.
1 Sept 2022

Are grapes OK for diabetics? ›

Grapes are adored, nourishing fruits and are safe for diabetics. People can eat them and add them to their diabetic diets as they do not harm or spike glucose levels. Consuming grapes help to reduce the susceptibility to developing type 2 diabetes.

Why can't diabetics have grapefruit? ›

Grapefruit is unique in that it has an enzyme-binding ability. This means that it may cause certain medications to pass from the GI tract into the bloodstream faster than normal, raising the amount of medication in your bloodstream, which can be potentially dangerous.

Is broccoli good for diabetes? ›

Broccoli may also help manage your blood sugar levels. One study found that consuming broccoli sprouts led to a reduction in blood glucose in people with diabetes ( 18 ). This reduction in blood glucose levels is likely due to sulforaphane, a chemical in cruciferous vegetables like broccoli and sprouts.

Is pumpkin good for diabetes? ›

Pumpkin is a healthy food rich in nutrients and compounds that can support blood sugar control. Several animal studies have shown that it may lower blood sugar, potentially improving diabetes management and helping slow the progression of the disease in some cases.

What can cause false high blood sugar readings? ›

However, various factors such as application errors, extreme environmental conditions, extreme hematocrit values, or medication interferences may potentially falsify blood glucose readings. Incorrect blood glucose readings may lead to treatment errors, for example, incorrect insulin dosing.

Why does blood sugar go up when fasting? ›

Glucagon during fasting

When fasting the hormone glucagon is stimulated and this increases plasma glucose levels in the body. If a patient doesn't have diabetes, their body will produce insulin to rebalance the increased glucose levels.

Is cheese good for diabetics? ›

Cheese can be included in any diet because it contains protein, vitamins and minerals, and healthy fats. Cheese can be a great addition to a type 2 diabetes diet as long as it is consumed in moderation. At least one study¹ has found that cheese may actually be able to lower the risk of developing type 2 diabetes.

What is the number one worst food for diabetics? ›

1. Sugar. People with diabetes should avoid sugary foods such as pastries, sweets, cakes, cookies, candy, and chocolate. According to Lakshmi, excessive use of sugar-sweetened foods and beverages can lead to obesity, which raises the risk of high blood sugar.

What is the number one snack to lower blood sugar? ›

Luckily for all of us, there are several foods that can help you maintain healthy blood sugar levels. But there is one food that stands alone as the best snack for lower blood sugar: nuts. Nuts are delicious, nutritious and incredibly versatile as far as snack foods go.

What food brings down blood sugar quickly? ›

List of foods that lower blood sugar levels (and promote blood sugar balance) over time
  • Oats.
  • Beans and lentils.
  • Salmon and other fatty fish.
  • Eggs.
  • Nuts and nut butters.
  • Seeds and seed butters.
  • Unsweetened yogurt and kefir.
  • Fermented vegetables.

Does cheese raise blood sugar? ›

Will cheese affect blood sugar levels? Cheese has a low glycemic index (GI), meaning that it releases glucose slowly and will not trigger significant blood glucose spikes.

What snacks can diabetics eat freely? ›

Here are some grab-and-go snacks that can be healthy picks when you have type 2 diabetes.
  • A handful of nuts. ...
  • Veggie sticks and hummus. ...
  • Nut butter and celery sticks. ...
  • Plain low fat Greek yogurt with berries. ...
  • Popcorn. ...
  • String cheese. ...
  • Hard-boiled eggs. ...
  • Tuna and crackers.
19 Feb 2019

How long does it take cinnamon to lower blood sugar? ›

One study showed that consuming 1 gram (g) of cinnamon extract daily for 12 weeks reduced fasting blood sugar levels and improved markers of oxidative stress in people with type 2 diabetes ( 8 ).

What food washes out sugar from blood? ›

Increase Your Protein & Fat Intake

An increase in healthy fat intake also helps in sugar detox. Healthy fats include avocado, unsweetened coconut products, grass-fed butter or ghee (unless you are lactose-intolerant), nuts, and seeds. Aim for 1-2 tablespoons of healthy fat with each meal.

Can drinking a lot of water lower your blood sugar? ›

Drinking water regularly may rehydrate the blood, lower blood sugar levels, and reduce diabetes risk ( 20 , 21 ). Keep in mind that water and other zero-calorie drinks are best. Avoid sugar-sweetened options, as these can raise blood glucose, drive weight gain, and increase diabetes risk ( 22 , 23 ).

What are the worst breakfast foods for diabetics? ›

Sugary cereals, bagels with cream cheese, and fried bacon are all popular breakfast foods, but they are not healthful options and can be poor choices for people with type 1 or type 2 diabetes.

Is peanut butter good for diabetics? ›

Peanut butter can definitely be part of a healthy diabetes diet plan. Always look for peanut butter that contains only peanuts and maybe some salt. Avoid peanut butter that includes added sugars and hydrogenated oils.


1. The WORST & BEST FOODS to Eat for Your BLOOD SUGAR! (Prevent Chronic Disease) | Dr. Casey Means
(Jesse Chappus)
2. The Most Accurate Method To Test Blood Sugar is NOT A1C Test – Dr. Berg
(Dr. Eric Berg DC)
3. What should your glucose levels be? Here’s the ultimate guide to healthy blood sugar ranges
4. 10 Harmful Foods Diabetics Keep Eating
(Type One Talks)
5. LOW blood SUGAR in Diabetics (hypoglycemia). Everything you NEED to know!
6. Everything You Were Told to Eat Is Wrong - Continuous Glucose Monitoring (CGM) Levels | Ep. 2
(Ali Spagnola's Fitness Outrageous)
Top Articles
Latest Posts
Article information

Author: Duane Harber

Last Updated: 01/06/2023

Views: 6247

Rating: 4 / 5 (51 voted)

Reviews: 90% of readers found this page helpful

Author information

Name: Duane Harber

Birthday: 1999-10-17

Address: Apt. 404 9899 Magnolia Roads, Port Royceville, ID 78186

Phone: +186911129794335

Job: Human Hospitality Planner

Hobby: Listening to music, Orienteering, Knapping, Dance, Mountain biking, Fishing, Pottery

Introduction: My name is Duane Harber, I am a modern, clever, handsome, fair, agreeable, inexpensive, beautiful person who loves writing and wants to share my knowledge and understanding with you.