“But I Don’t Eat Sugar…” So Why Is My Fasting Blood Sugar High?

One of the first things I hear when someone's fasting blood sugar comes back high is:

“But I don't eat much sugar.”

Usually followed by:

“I barely eat carbs.”

And that may be completely true.

But here's what most people don't realize:

High blood sugar isn't always a sugar problem.

Your fasting glucose isn't simply a report card showing how much sugar or how many carbohydrates you ate yesterday. It's also giving you information about how well your body is managing glucose and responding to insulin.

And there are a lot of things that affect that.

“But I Barely Eat Carbs.”

Reducing excessive sugar and refined carbohydrates can certainly be helpful, especially if they make up a large portion of your diet.

But simply not eating much sugar or carbohydrates doesn't automatically mean you're metabolically healthy.

You could eat very little sugar but:

• Sit most of the day

• Rarely exercise

• Never strength train

• Have relatively little muscle mass

• Carry significant excess body fat

• Regularly consume more calories than your body needs

• Eat a poor-quality, highly processed diet

• Consistently sleep five or six hours a night

• Live under chronic stress

…and still have problems regulating blood glucose.

That's because insulin resistance isn't simply about how much sugar you eat.

It's about how effectively your body is managing energy.

You Don't Have to Eat Glucose for Glucose to Enter Your Bloodstream

This is probably the biggest misconception.

Your body can make glucose.

Your liver stores glucose and releases it into your bloodstream when your body needs energy. It can also make new glucose from other substrates.

That's a good thing.

You're asleep for eight hours and aren't eating, yet your brain and other tissues still need energy. Your body has systems designed to make sure fuel remains available.

Insulin is one of the major signals helping regulate this process.

When everything is working properly, insulin helps your tissues take glucose out of the bloodstream and also helps regulate how much glucose your liver releases.

But when you become insulin resistant, your body doesn't respond to insulin's signal as effectively.

Your pancreas initially compensates by producing more insulin.

For a while, that may work.

Your blood glucose might even look relatively normal because your pancreas is working harder to keep it there.

That's why an important concept to understand is:

Insulin resistance can be developing long before fasting glucose becomes obviously elevated.

Eventually, your body's ability to compensate may become less effective and fasting glucose can begin creeping upward.

Now you're looking at your lab results thinking:

“Where is all this sugar coming from? I didn't eat it.”

You didn't necessarily have to.

Some of that glucose came from your own liver.

This Is Why Strength Training and Muscle Matter So Much

We tend to think of muscle in terms of strength, athletic performance or appearance.

But muscle is also extremely important metabolically.

Skeletal muscle is one of the body's major destinations for glucose.

After you eat, a significant amount of glucose can be taken up by skeletal muscle. And when your muscles contract during physical activity, they increase their demand for fuel.

That's one of the reasons I put such a strong emphasis on strength training and maintaining muscle, especially as we get older.

You don't just want to lose weight.

You want to build and preserve metabolically active muscle tissue.

Think of muscle as additional capacity for your body to use and store glucose.

Walking is great.

Cardiovascular exercise is great.

Moving throughout the day is extremely important.

But I wouldn't stop there.

Strength train.

Challenge your muscles.

Give your body a reason to maintain them.

And whenever appropriate, build more muscle.

Because as we age, doing nothing is not a neutral strategy. We naturally become more susceptible to losing muscle mass, particularly if we're sedentary and don't provide our muscles with a reason to stick around.

Less muscle combined with less activity is exactly the opposite direction we want to go for long-term metabolic health.

Now compare two lifestyles.

Person A:Strength trains several times a week, walks regularly, carries a healthy amount of muscle, sleeps reasonably well and eats mostly nutrient-dense foods.

Person B:Sits most of the day, rarely exercises, doesn't strength train, has relatively little muscle, sleeps poorly and consistently overeats.

Person B might truthfully tell me:

“But I don't eat sweets.”

That's useful information.

But it doesn't tell me nearly enough.

I also want to know:

How much do you move?

Do you strength train?

Are you maintaining muscle as you age?

Are you actually challenging that muscle regularly?

Because muscle isn't just something that makes you look better in a T-shirt.

Muscle is metabolic machinery.

The more effectively you build it, maintain it and use it, the better equipped your body is to deal with the fuel you're giving it.

That's a much bigger conversation than simply:

“Stop eating carbs.”

Sitting All Day Matters Too

You can strength train for an hour and still spend most of your day sedentary.

That's something people often overlook.

Think about the difference between someone getting 8,000–10,000 steps throughout the day and someone getting 2,000.

That adds up.

Walking after meals can be especially useful because you're contracting muscle at the same time your body is dealing with nutrients from that meal.

You don't necessarily need another brutal workout.

Sometimes you just need to move more.

Take a walk.

Use the stairs.

Get up from your desk.

Walk after dinner.

Stop looking at exercise as something that only happens during the 60 minutes you're at the gym.

Strength training and daily movement aren't competitors.

You want both.

Strength training helps you build and maintain the machinery.

Daily activity gives you opportunities to use it.

Body Fat and Chronic Overconsumption Matter

This is another uncomfortable part of the conversation, but an important one.

Your body has to do something with excess energy.

If calorie intake consistently and substantially exceeds what you're using, that excess energy has to be stored.

Initially, your body is very good at storing energy in fat cells.

But there are limits to how much excess energy your body can continually manage without consequences.

As fat tissue expands and metabolic health deteriorates, excess fat can increasingly accumulate in places where you don't want it — including the liver and around internal organs.

That can interfere with normal metabolic signaling and contribute to insulin resistance.

So someone can truthfully say:

“I don't eat much sugar.”

But if they're consistently consuming more energy than their body needs and carrying significant excess body fat, eliminating sugar alone doesn't solve the problem.

Your body cares about the entire metabolic environment — not whether the excess calories came from something labeled “low carb.”

Your Overall Diet Still Matters

There's also a huge difference between:

“I don't eat sugar.”

and:

“I eat well.”

Those aren't necessarily the same thing.

A diet can be low in sugar and still consist primarily of calorie-dense, highly processed foods with very little fiber, fruits, vegetables or other nutrient-dense whole foods.

Conversely, eating an apple, beans, oatmeal or potatoes doesn't automatically make someone's diet unhealthy because those foods contain carbohydrates.

This is why I don't like reducing nutrition to:

CARBS = BAD.

The better question is:

What does your overall diet look like?

Food quality matters.

Portions matter.

Total energy intake matters.

Protein matters.

Fiber matters.

And what you consistently do over months and years matters far more than one meal.

And Then There's Sleep

This one gets ignored constantly.

You can have a great workout program and a pretty good diet and still be working against yourself if you're chronically sleeping five hours a night.

Sleep plays an important role in metabolic health, including glucose regulation and insulin sensitivity.

One bad night's sleep isn't going to suddenly make you diabetic.

But consistently poor sleep can contribute to the metabolic environment we're talking about.

And poor sleep tends to create other problems.

You're tired.

You move less.

Training quality suffers.

You're hungrier.

Food choices often get worse.

Recovery suffers.

Stress increases.

Then people try to solve the entire problem by removing the teaspoon of sugar from their morning coffee.

Look at the bigger picture.

Why Can My Blood Sugar Be Highest in the Morning?

Here's another one that confuses people.

You haven't eaten all night.

So shouldn't your blood sugar be at its lowest?

Not necessarily.

As morning approaches, your body begins preparing you to wake up.

Hormonal changes signal your liver to make more glucose available so you have energy to get up and start your day.

This normal process contributes to what's commonly called the dawn phenomenon.

Think about what that means.

You haven't eaten breakfast.

You haven't had juice.

You haven't put sugar in your coffee.

You haven't eaten anything.

Yet glucose can still rise.

You didn't eat that glucose.

Your body put it there.

For someone whose glucose regulation is working well, the body generally manages that rise appropriately.

When insulin sensitivity and glucose regulation aren't working as effectively, that morning increase may be more noticeable.

Stop Looking at One Number

Fasting glucose is useful.

But it's one piece of information.

That's why I'm a big believer in looking at trends and context, rather than obsessing over a single lab value.

Depending on what you and your healthcare provider are evaluating, that might include looking at things such as:

• Fasting glucose

• HbA1c

• Fasting insulin

• Triglycerides

• HDL

• Waist circumference

• Body composition

• Changes in these measurements over time

  
  

One abnormal fasting glucose reading doesn't tell your entire metabolic story.

But repeatedly elevated fasting glucose shouldn't simply be dismissed because:

“I don't eat sugar.”

Instead, use it as a reason to start asking better questions.

Ask Better Questions

Instead of only asking:

“How much sugar am I eating?”

Ask:

How much am I moving every day?

Am I strength training consistently?

Am I building or at least maintaining muscle as I get older?

Am I challenging those muscles enough to give my body a reason to keep them?

Am I carrying more body fat than I should?

Am I consistently eating more energy than I'm using?

What does the quality of my overall diet look like?

How am I sleeping?

How am I managing stress?

What does my fasting insulin look like?

What has my fasting glucose been doing over the last several years?

Those questions give you a much better picture of what's happening.

The Bottom Line

If your fasting blood sugar comes back elevated, don't immediately assume:

“I must be eating too much sugar.”

But don't dismiss it by saying:

“That can't be right. I barely eat carbs.”

Your body is much more complicated than that.

Your activity level matters.

Strength training matters.

Your muscle mass matters.

Your body composition matters.

Your overall diet matters.

Your sleep matters.

Your total energy intake matters.

And your insulin sensitivity matters.

Reducing excessive sugar may absolutely be part of improving your health.

But the goal isn't simply to eat less sugar.

The goal is to build a body that's better at using and managing energy.

Move more.

Strength train.

Build and preserve muscle.

Eat well.

Sleep.

Maintain a healthy body composition.

And pay attention to the trends in your bloodwork.

Because the answer to poor metabolic health isn't always eating fewer carbs.

Sometimes part of the answer is building a body that's better equipped to use them.

Your fasting blood sugar isn't simply telling you what you ate yesterday.

It's giving you information about how well your body is managing energy.

This article is for educational purposes only and is not intended to diagnose or treat any medical condition. Discuss abnormal laboratory results and appropriate testing with your healthcare provider.