Even if you don’t have diabetes, you should care about your glucose levels. Managing your glucose keeps your energy stable, your mind clear, and your chronic disease risk down.
The good news is that glucose levels are highly modifiable. You can limit glucose spikes by minding your carbs, exercising, and—assuming you’re not on the “all smoothie diet”—eating foods in a particular order.
We’ll review these (and other) glucose management tips shortly. First, though, let’s cover why glucose matters.
Why You Shouldn’t Ignore Glucose
When someone has type 2 diabetes, they can’t regulate blood glucose (blood sugar) properly. Consequently, their glucose levels stay high, increasing the risk of blood vessel damage, heart disease, kidney disease, and—ultimately—death.[*]
Unfortunately, many people with type 2 diabetes don’t realize it. According to one estimate, 45.8% of cases (174.8 million patients globally) remain undiagnosed.[*]
Worse, prediabetes rates are about three times higher.[*] Most of these folks don’t know they have a glucose problem. Many will develop full-blown diabetes.
And so, hundreds of millions (maybe billions) of people worldwide are in poor metabolic health. They’re at higher risk of heart disease, cancer, neurodegenerative disease, and other degenerative conditions—and many don’t even know it.
That’s the chronic disease argument for managing glucose, and it’s pretty persuasive. But there are other reasons too.
Why Are Glucose Spikes Bad?
Leaving aside diabetes and prediabetes, why should you care about glucose? Because even transient glucose spikes have negative consequences you don’t want.
Did you know that a glucose spike damages DNA and suppresses DNA repair?[*] Or that high blood sugar accelerates skin aging, promotes cataract formation, impairs cognition, shuts down fat burning, and is linked to a higher risk of severe COVID-19?[*][*][*][*]
Then there are the squishier, more subjective consequences—like the effects on hunger, cravings, and energy levels.
Picture a kid given full possession of their Halloween candy (don’t try this at home, folks!). They eat 100 grams of sugar in ten minutes, glucose skyrockets, mania ensues, the sugar wears off, their mood plummets, cravings kick in, they eat more candy, and the cycle continues.
It’s not just kids with candy, though. Any carbohydrate (especially refined carbohydrates) can spike blood sugar.
We’ll drill into that topic soon after a brief word about glucose levels.
What Should Your Glucose Levels Be?
Here’s how the American Diabetes Association classifies diabetes risk:[*]
- Normal: Fasting blood glucose (FBG) below 100 mg/dl, HbA1c (average blood glucose) below 5.7%
- Prediabetes: FBG between 100–125 mg/dl, HbA1c between 5.7–6.4% (inclusive)
- Diabetes: FBG above 125 mg/dl, HbA1c above 6.4%
“Normal”, however, isn’t necessarily optimal. In one large study, fasting glucose levels below 85 mg/dl correlated with a 2.33X lower risk of developing diabetes than “normal” levels between 95-99 mg/dl.[*] The data also suggest that HbA1c levels below 5% are better (heart health-wise) than “normal” levels between 5.4–5.6%.[*]
What about post-meal glucose excursions? The literature suggests that these spikes are a better predictor of heart issues than fasting glucose[*]—and that managing them is an effective longevity strategy.[*]
According to published guidelines, people with diabetes should keep post-meal glucose below 180 mg/dl, and people without diabetes should keep it below 140 mg/dl.[*] Lower is generally better here, so consider these upper limits.
Diet and Glucose Levels
Diet is the sharpest tool in your glucose management toolbox. To avoid blood sugar spikes, avoid foods that spike your blood sugar.
The simplest strategy is to mind your macros—your carb, protein, and fat intake. Carbs spike blood glucose most, protein moderately, and fat very little.
Why do you think low-carb and Keto diets work so well for glucose management?[*][*] By restricting carbs, both glucose and insulin (your glucose regulation hormone) stay lower.
Not all carbs affect blood glucose equally, though. Whole food carbs (fruits and vegetables) contain fiber to slow digestion and reduce blood sugar spikes—while refined carbs explode like a glucose bomb in your small intestine.
The takeaway is that a well-formulated whole foods diet is usually sufficient for glucose management. But some folks will need (or enjoy) the additional metabolic benefits of carb restriction.
Common Questions About Preventing Glucose Spikes
Let’s shift gears for a moment and do a glucose spikes FAQ.
How does exercise affect glucose levels?
Regular exercise improves the function of insulin, your glucose regulation hormone.[*] Blood sugar spikes don’t last long when insulin functions well.
All types of exercise improve metabolic health, but high-intensity interval training (HIIT) deserves special mention. In one study, just three 15-minute weekly sessions improved insulin sensitivity in older adults.[*]
What are some foods that don’t spike glucose?
Any Keto-approved food—meat, fish, nuts, avocados, healthy fats, and non-starchy vegetables—won’t spike glucose. Most carb-containing foods will spike glucose, but fiber-rich whole foods (apples, berries, sweet potatoes) cause smaller spikes than processed foods.
What’s the best food order to reduce glucose and insulin levels?
Just consume protein, fat, and fiber before carbs. In one study, people who ate protein and vegetables ten minutes before their carbs (instead of carbs first) had over 40% smaller glucose spikes.[*]
Does stevia spike glucose?
Actually, some studies suggest stevia lowers blood glucose when taken with carbs.[*] Another paper found that eight weeks of stevia sweetening didn’t affect glucose or insulin levels in people with type 2 diabetes.[*]
Can I take apple cider vinegar to lower blood glucose?
A meta-analysis of 11 clinical trials found that apple cider vinegar (doses of 2–50 grams) significantly reduced post-meal blood sugar.[*] Potential mechanism: the acetic acid in vinegar slows digestion, limiting glucose spikes.
A Holistic Approach to Your Glucose
Start with diet, but don’t neglect lifestyle factors. The three S’s—stress, sleep deprivation, and sedentary living—can hold you back from your healthiest glucose levels.
- Stress increases fight-or-flight hormones like cortisol and adrenaline, which raise glucose levels.[*]
- Sleep deprivation decreases insulin sensitivity, so glucose stays higher for longer.[*]
- Sedentary living is linked to a 112% higher risk of developing type 2 diabetes, according to a meta-analysis of ten studies[*]
Do your best to mind these areas. Getting this big stuff right will make it that much easier to achieve optimal glucose levels (and overall health).