Blood Work Series, Part 2: Metabolic Health

What Your Blood Sugar and Fats Are Really Telling You

In last week’s post on Vitamin D, we talked about why blood work matters so much more than just whether something falls inside a wide “normal” reference range. We looked at how Vitamin D functions as a hormone, why deficiency is so common, and how optimizing levels can dramatically impact immune function, mood, recovery, and long‑term health.

This week, we’re continuing the Blood Work series by zooming out to something even more foundational: metabolic health.

Specifically, we’re going to look at three simple, inexpensive labs that tell an enormous story about how your body handles fuel:

• Fasting Blood Glucose

• HbA1c

• Triglycerides

Individually they’re useful. Together, they provide a powerful snapshot of how much sugar and fat are floating around in your bloodstream in a fasted state — and whether your metabolism is doing its job efficiently.

What Is Metabolic Health?

At its core, metabolic health describes how well your body can:

• Take in fuel (carbohydrate, fat, protein)

• Store it appropriately

• Access it when needed

• Keep blood sugar and blood fats tightly regulated

A metabolically healthy person can move seamlessly between fuels. A metabolically unhealthy person — often insulin resistant — cannot.

When that flexibility breaks down, fuel starts backing up into the bloodstream. Sugar stays high. Triglycerides stay elevated. Insulin stays chronically elevated. And over time, that biochemical environment drives nearly every chronic disease we care about.

The Three Core Tests

1. Fasting Blood Glucose (FBG)

What it measures:

Fasting blood glucose measures how much glucose (sugar) is in your bloodstream after an overnight fast, typically 8–12 hours without food.

In a healthy metabolic system, fasting glucose should be low and stable, because:

• You’re not actively digesting food

• The liver is releasing only small, controlled amounts of glucose

• Insulin sensitivity is high

Optimal range:

• Ideal: 75–90 mg/dL

• Needs Attention: ≥100 mg/dL

Persistently elevated fasting glucose suggests that the body is struggling to regulate baseline blood sugar — often due to insulin resistance at the liver.

2. HbA1c

What it measures:

HbA1c (hemoglobin A1c) measures the percentage of red blood cells that have glucose attached to them. Because red blood cells live ~90–120 days, HbA1c reflects your average blood sugar over the past 2–3 months.

Think of it as a long‑term exposure marker rather than a snapshot.

Optimal range:

• Ideal: ≤5.4%

• Prediabetes: 5.7–6.4%

HbA1c tends to rise when blood sugar spikes frequently, stays elevated longer than it should, or both.

3. Triglycerides

What they measure:

Triglycerides are the primary form of fat in the bloodstream. After you eat — especially carbohydrates — excess energy is packaged into triglycerides and transported through the blood.

In a fasted state, triglycerides should be low, because fat should be stored in fat tissue, not circulating aimlessly in the blood.

Optimal range:

• Ideal: <100 mg/dL

• Needs Attention <150 mg/dL

Elevated triglycerides are often a marker of carbohydrate intolerance and insulin resistance.

Why You Don’t Want Fuel in the Bloodstream

Blood is a transport system, not a storage unit.

When sugar and fat linger in the bloodstream:

• Glucose damages blood vessels via glycation

• Triglycerides promote inflammation and atherosclerosis

• Insulin remains chronically elevated

• Cells become less responsive to insulin over time

This is why insulin resistance is such a big deal. It’s not just about blood sugar — it’s about cellular energy failure.

My Numbers — And Why They’re Interesting

Here are my recent results:

• Triglycerides: 52 mg/dL (excellent)

• Fasting Blood Glucose: 107 mg/dL (not great)

• HbA1c: 5.6% (down from 5.8% last year)

On the surface, this is a mixed picture.

Triglycerides are squarely in the optimal range, which aligns with how I eat: mostly meat, fruit, vegetables, and healthy fats, with minimal processed food and only intermittent treats like dark chocolate or potato chips.

However, my fasting glucose and HbA1c remain higher than I would expect given:

• My body fat (mid‑teens even without consistent training)

• My diet quality

• My overall lifestyle

Even when I eat very clean, these numbers don’t move dramatically — though the slow improvement in HbA1c suggests something positive is happening.

So what gives?

Why These Numbers Can Be Elevated Without a Bad Diet

This is where nuance matters.

Not all metabolic markers are driven purely by food choices. Some common non‑diet contributors include:

1. Genetic Predisposition

Some people are genetically predisposed to:

• Higher baseline fasting glucose

• Greater hepatic (liver‑based) insulin resistance

• Slower glucose clearance

This is often seen in people who stay lean easily but still show mild glycemic dysregulation.

2. Stress and Cortisol

Chronic psychological or physiological stress raises cortisol, which:

• Signals the liver to release more glucose

• Elevates fasting blood sugar

• Impairs insulin sensitivity

You can eat perfectly and still wake up with elevated glucose if stress is high.

3. Sleep Quantity and Quality

Poor sleep — even for a few nights — measurably worsens insulin sensitivity.

Short sleep duration and fragmented sleep:

• Raise fasting glucose

• Increase HbA1c

• Increase hunger and carbohydrate cravings

4. Low Muscle Mass or Low Activity

Skeletal muscle is the largest glucose sink in the body.

Less muscle mass or inconsistent resistance training = fewer places for glucose to go.

5. Dawn Phenomenon

Some individuals experience a pronounced early‑morning rise in glucose due to circadian hormone release.

This can elevate fasting glucose even when overall metabolic health is decent.

The Most Powerful Interventions for Metabolic Health

While supplements and biohacks get attention, behavior still dominates. If your metabolic health needs attention, this is how to get the picture to shift in the right direction. 

1. A Whole‑Foods Diet

The foundation:

• Eliminate ultra‑processed foods

• Minimize refined carbohydrates

• Emphasize meat, fruit, vegetables, and healthy fats

This reduces glucose load and volatility and lowers triglyceride production at the liver.

2. Sleep

Improving sleep duration and quality often produces:

• Lower fasting glucose

• Improved insulin sensitivity

• Reduced cravings

Sleep is not optional for metabolic repair.

3. Regular Activity and Exercise

The most metabolically protective combination:

• Low‑intensity movement (walking, daily steps)

• Aerobic training (Zone 2 or aerobic threshold work)

• Resistance training (muscle mass acts as a powerful glucose sink)

It's worth mentioning, exercise increases insulin sensitivity independent of weight loss.

What Better Metabolic Health Feels Like

This is the big one. While you often hear metabolic health mentioned in the context of long term health and chronic disease, you can change your metabolic health meaningfully in just a matter of weeks and reap some pretty cool benefits day to day. In the short term, people often notice:

• More stable energy throughout the day meaning no mid afternoon crash

• Improved mental clarity and focus driven by better fuel delivery to the brain

• Better mood and emotional resilience 

• Easier fat loss or body recomposition

This isn’t subtle — as my clients change their habits around food and sleep they often say "I had no idea I could feel this good" or that they thought it would take longer to see changes. 

Long‑Term Consequences (and Opportunities)

Poor metabolic health is the cause of — not merely correlated with:

• Type II diabetes

• Heart disease

• Stroke

• Fatty liver disease

• Many cancers

• Alzheimer’s disease and other dementias

Emerging research increasingly frames Alzheimer’s as a metabolic disease of the brain.

Newer studies show that improving insulin sensitivity and metabolic flexibility can acutely improve cognitive performance and slow cognitive decline, even later in life. 

This is huge considering the pharmaceuticals we have to treat alzheimers and cognitive decline are not currently very effective. However there are plenty of examples in the literature where even severe symptoms have been reversed through big changes in diet, sleep, and exercise. 

This makes metabolic health one of the highest‑leverage targets for both longevity and quality of life.

How Often Should You Test?

One of the most common questions I get after reviewing labs is: “How long will it take for this to change?”

The answer depends on the marker.

• Fasting Blood Glucose can improve relatively quickly — sometimes within 1–3 weeks — because it’s highly sensitive to sleep, stress, and recent activity levels.

• Triglycerides are also fairly responsive and often improve within 2–6 weeks, especially when processed carbohydrates and alcohol are reduced.

• HbA1c moves the slowest by design. Because it reflects roughly 90 days of blood sugar exposure, meaningful changes typically require 8–12 weeks of consistent behavior change.

For most people, re‑testing every 3–4 months strikes the right balance: frequent enough to see progress, but long enough for real physiology to shift.

If You Only Fix One Thing

If you’re feeling overwhelmed, start here.

Eliminate processed foods.

A simple rule of thumb: if it’s something you couldn’t realistically make in your own kitchen, it probably doesn’t belong in your regular rotation.

Processed foods — especially processed carbohydrates — are uniquely disruptive because they:

• Deliver sugar and starch in forms the body absorbs extremely quickly

• Drive larger blood sugar spikes

• Increase triglyceride production at the liver

• Promote insulin resistance over time

You don’t need perfection. You don’t need macro tracking. You don’t need supplements.

Just removing foods that come from factories instead of farms or kitchens often produces outsized improvements in metabolic health all by itself.

Coming Next: Cholesterol (And Why Our View Is Different)

Next week in the Blood Work series, we’re tackling cholesterol — one of the most misunderstood and emotionally charged lab categories in medicine.

We take a more contrarian view.

You might be doing better with higher cholesterol than your doctor is willing to admit — and in some cases, aggressively lowering cholesterol can actually mask deeper metabolic problems rather than fix them.

We’ll break down:

• Why total cholesterol is often a poor standalone metric

• Which cholesterol markers actually matter

• How cholesterol, metabolic health, and inflammation are tightly linked

• And when high cholesterol may be a sign of resilience rather than risk

More to come.