How Sugar Damages Your Immune System + How to Cut It Out

By Elizabeth Leppart, MS, LN
April 7, 2020

eat_sugar.jpgMost people are aware that eating sugar has negative consequences to our health, leading to health conditions like obesity and diabetes.

However, most haven’t made the connection that sugar also has an effect on our immune system. A big impact at that – immune function decreases for hours after sugar is consumed.

A research study done by Loma Linda University in which participants were fed different forms of sugar found that the effectiveness of white blood cells - our immune cells which fight infection - decreased up to 50% after 1-2 hours of eating sugar, lasting up to five hours! (1) Yikes.

Sugar and COVID-era Eating Habits

It’s ironic, but at a time when we should be avoiding sugar many people are using quarantine time to bake, bake, bake. And while I understand this is a comfort measure for many, it’s simply not worth the added stress it puts on your immune systems.

You can still have fun in the kitchen when you replace those cookies and cakes with Chocolatey Fat Bombs and Oatmeal Almond Balls. Both are delicious, small snacks that are free of processed sugar and full of nutrients designed to keep your body functioning at its best ability.   

Hidden Sugars That Aren't in Sweets

You may be thinking you’re in the clear because you avoid sugary treats like soda or the abovementioned baked goods … but you may want to think again. If you’re consuming any processed food like bagels, pizza, crackers or popcorn (just to name a few), you’re consuming sugar without knowing it.

All processed foods break down into sugar in our blood stream. To understand how much sugar you’re consuming, all it takes is a simple equation. Four grams of any carbohydrate breaks down into one teaspoon of sugar in our blood. For example, one cup of cooked plain spaghetti is about 43 grams of carbohydrate, which breaks down into almost 11 teaspoons of sugar. If you were to replace the spaghetti with one cup of zucchini noodles at 3.7 grams per cup, it would equate to less than one teaspoon of sugar!

spaghetti 11tsp sugar-01.jpg

According to Dr. Mark Hyman’s book Food: What the Heck Should I Eat?,Some estimates from US government surveys say that the average American consumes 152 pounds of sugar and about 133 pounds of flour [which convert to sugar] annually. That’s more than a third of a pound per person per day.” (2) This is because 75% of processed foods also have added hidden sugars!

Some of the biggest culprits of hidden sugar are condiments like ketchup and BBQ sauce, salad dressings, crackers, pasta sauces, and vegetable juices. Try reading labels of products in your pantry or next time you’re at the grocery store to see where sugar is hiding.

Diet Choices to Support Your Immune System

Instead of of focusing on sugar, which we don’t want to eat, let's turn this around. Delicious real foods support our immune system. Butter, bacon and fresh guacamole are a few of my favorites!

What counts as real food? Think about this, real vegetables are free of added sugar, real fruit is free of added sugar, meat and fish are free of sugar and natural fats are free of sugar.

Check out this recent blog post, What to Eat to Support Your Immune System + What to Skip to look at all the benefits these foods provide your immune system (and mood, which is also critical during this stressful time). By adding real foods we crowd out room for processed, sugary foods. One of the things I hear most often from clients and class participants is how amazed they are that their cravings are totally gone. Gone!

After struggling to control cravings for sometimes decades, it only took a few days of eating real food in balance to notice their cravings begin to vanish. Eating real protein, fat, and carbs in balance throughout the day stabilizes our blood sugar. When our blood sugar is stable, we feel calm and satisfied, so we are not wandering back into the kitchen for another snack.

Recipie_Hamburger-soup.jpgA Menu for Sugar-free Eating

To really hit home all that you can eat, here’s a sample menu of a typical day of eating that’s free of sugar and loaded with flavor and health. Rather than a breakfast that consists of low-fat yogurt and a muffin, which are mostly made up of sugar, try making scrambled eggs and vegetables with butter or coconut oil.

For lunch, instead of a sandwich and potato chips (remember that the bread and chips will break down into sugar), have a bowl of hamburger soup with sour cream and slices of avocado.

For dinner, swap out the pasta (remember that breaks down into sugar!) and sugar-laden sauce, with spiralized garlic veggie noodles cooked with fresh tomatoes, herbs, and topped with instant pot garlic herb chicken. Sounds very appetizing right this minute! Check out more real food recipes.

Have you tried to give up sugar in the past to no avail? Take our online class, Breaking the Sugar Habit, to curb cravings and improve health!

Enroll Today

If you think this all sounds great and all … but you’ve tried to give up sugar in the past to no avail, we can help with that.

Make an appointment with one of our nutritionists or dietitians to break free of sugar addiction!

Schedule an Appointment

I and the other nutritionists and dietitians at Nutritional Weight & Wellness have helped clients break free of their sugar addiction for years. During the coronavirus pandemic we are counseling clients via phone or video and are here to help you conquer cutting out sugar, support your immune system, manage anxiety or whatever other health goals you may have. Be in touch; we’re here to help.




(2) Hyman, Mark. Food: What the Heck Should I Eat? New York, NY, Little, Brown Spark, 2018.


About the author

Elizabeth is a licensed nutritionist Nutritional Weight & Wellness. Elizabeth knows the power of nutrition first hand. Having battled chronic digestive issues and a poor relationship with food throughout her life, she understands the frustration of searching for answers to feeling better. Through practicing a whole-foods based, balanced diet, Elizabeth was able to transform her relationship with food to one of nourishment and fulfillment, instead of deprivation and feeling drained.

View all posts by Elizabeth Leppart, MS, LN


Bunny Homa
I am 5'2" and weigh 102 lbs. I think I have issues with sugar as I'm always craving it. Today I baked pumpkin muffins with coconut sugar, and I often buy So Delicious frozen coconut milk treats. I put stevia in my tea, so sweet is definitely a craving. I have also thought of taking cooking classes as would like to eat more healthy. . I do not eat meat and I would like to let go of sugar.
April 8, 2020 at 5:10 pm


Yes, it's definitely a craving for many, which sounds like you can relate to. We'd encourage you to schedule a video or phone nutrition counsultation to get to the root of your cravings

Katherine Rivard
Nice article and reference.

Washington County Wellness just put out a cookbook with the garlic veggie spirals. I tested the recipe and wrote it for the little book. Zucchini or Butternut squash spirals or both were just great! Tomatoes added. It even looks pretty. I think we can allow starch for people who restrict their foods. But it sure takes a lot of trial and error to find what works for people out there. I am going to try the hamburger soup. Yum.
April 10, 2020 at 5:41 pm


Thanks! We're glad you found it helpful.

Does honey also counts as sugar? One of my favourite meal is plain greek yogurt mixed with cottage cheese (5%), one spoon of organic peanut butter and banana, some berries. But I add one teaspoon of honey for extra sweetness. Shoud I give it up and replace with dates for example or honey is ok?
June 11, 2020 at 4:36 am


Honey does count as sugar, but if you're only using one teaspoon in yogurt I wouldn't worry about cutting it out. Most of the sugar we want to cut out comes from processed carbohydrate foods.

Great article! I've loved your articulation of the effects of sugar on immunity. Just got me thinking how vulnerable we could be after ingesting high sugar foods during this Covid-19 pandemic era.

Your explanation that four grams of any carbohydrate breaks down into one teaspoon of sugar in our blood was a rude awakening to my attempts at living healthy. Although I use almost an entirely whole grain diet, I will sure pay more attention to reducing my intake of carbohydrates.
August 6, 2020 at 8:06 am


Glad you found this info helpful!

What can I suggest as healthier alternatives to my toddler’s daycare? They serve Cheerios/Shreddies or other similar cereal for breakfasts. They serve Ritz crackers or Arrowroot cookies, or other similar crackers/cookies, for daily afternoon snacks. I can see that their focus is convenience and cost, but I’m concerned about the sugar (and other additives). Thank you.
September 30, 2020 at 10:03 pm


We have some great resources on our website for what to feed kids and toddlers. Just like adults, we suggest real food (meat, fruits and veggies, healthy fats like nuts or avocado). Some easy options your daycare could implement are deli meat rollups, hard-boiled eggs, cheese sticks, yogurt pouches, fruits and veggies.

4 Realistic Tips for Helping Kids Eat Healthy Foods
Ugh! My Kid Wants to Eat All the Time! 4 Snacks to Make Together
Tips for Feeding Kids Who Are Picky Eaters


Cutting up strips of red peppers now to snack on after listening to the radio show this AM. Thank you!
December 10, 2022 at 8:36 am

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