Primary Causes & Action Plans

Fasting Insulin

The earliest marker of metabolic dysfunction
Fasting insulin measures the amount of insulin your pancreas produces to maintain normal blood sugar after an overnight fast. Elevated fasting insulin is the earliest detectable sign of insulin resistance, appearing years to decades before blood sugar itself rises. It is arguably the single most important metabolic biomarker that most doctors do not routinely order.
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Target < 5 uIU/mL (optimal)
Suggested Action Plan

If fasting insulin is elevated, prioritize reducing refined carbohydrates and sugar. Time-restricted eating (intermittent fasting) can improve insulin sensitivity. Regular resistance training and Zone 2 cardio both independently improve insulin sensitivity. Retest every 3-6 months to track progress.

HbA1c

Your 90-day blood sugar average
Hemoglobin A1c (HbA1c) measures the percentage of hemoglobin proteins in red blood cells that have glucose attached. Because red blood cells live approximately 90-120 days, HbA1c provides a rolling 3-month average of blood sugar levels. It is the standard diagnostic test for diabetes and prediabetes.
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Target < 5.2% (optimal)
Suggested Action Plan

If HbA1c is elevated, reduce refined carbohydrates and added sugars. Increase fiber intake. Exercise regularly, especially after meals. Consider continuous glucose monitoring to identify personal glucose-spiking foods. Retest in 3 months.

Fasting Glucose

Your baseline blood sugar level
Fasting glucose measures blood sugar after an overnight fast of at least 8 hours. It is the most common screening test for diabetes, though it only becomes abnormal late in the disease progression. Many people develop significant insulin resistance while maintaining normal fasting glucose through compensatory insulin production.
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Target < 90 mg/dL (optimal)
Suggested Action Plan

If fasting glucose is elevated, test fasting insulin and calculate HOMA-IR for a complete picture. Reduce refined carbohydrates. Walk for 10-15 minutes after meals. Prioritize sleep and stress management, both of which significantly affect blood sugar regulation.

HOMA-IR

Calculated insulin resistance score
HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) is calculated from fasting insulin and fasting glucose: (insulin x glucose) / 405. It quantifies insulin resistance on a single scale, making it easier to track metabolic health over time. A HOMA-IR below 1.0 indicates excellent insulin sensitivity.
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Target < 1.0 (optimal)
Suggested Action Plan

Reduce HOMA-IR through the same strategies that lower fasting insulin: restrict refined carbohydrates, exercise regularly (both resistance training and cardio), achieve a healthy body composition, manage stress, and optimize sleep. Track HOMA-IR over time to gauge progress.

Triglyceride/HDL Ratio

Surrogate marker for insulin resistance and small dense LDL
The triglyceride-to-HDL cholesterol ratio is a simple, inexpensive surrogate marker for insulin resistance. It reflects the metabolic shift toward atherogenic dyslipidemia that accompanies insulin resistance: elevated triglycerides, low HDL, and increased small dense LDL particles. This ratio can be calculated from any standard lipid panel.
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Target < 1.5 (optimal)
Suggested Action Plan

Lower your TG/HDL ratio by reducing refined carbohydrates (the primary driver of elevated triglycerides), increasing healthy fats (olive oil, avocado, nuts, fatty fish), exercising regularly, and achieving a healthy body weight. Therapeutic-dose omega-3s can help lower triglycerides.

C-Peptide

Measures actual insulin production by the pancreas
C-Peptide is released in equal amounts to insulin when proinsulin is cleaved in the pancreas. Unlike insulin, which is partially cleared by the liver on first pass, C-Peptide circulates with a longer half-life and provides a more stable measure of endogenous insulin production. It is particularly useful for distinguishing type 1 from type 2 diabetes and assessing remaining beta cell function.
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Target 1.0 - 2.5 ng/mL (optimal)
Suggested Action Plan

C-Peptide interpretation depends on context. In suspected type 2 diabetes, elevated C-Peptide confirms insulin resistance with preserved beta cell function (reversible). Low C-Peptide with high glucose suggests beta cell failure or type 1 diabetes. Work with an endocrinologist for proper interpretation.

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Getting Started

1
Test Fasting Insulin Early

Do not wait for blood sugar to become abnormal. Request fasting insulin alongside your standard glucose and HbA1c tests. This can detect insulin resistance 10-15 years before a diabetes diagnosis, when the condition is fully reversible.

2
Monitor Trends Over Time

A single snapshot is less valuable than a trend. Test metabolic markers every 3-6 months and track your HOMA-IR and TG/HDL ratio over time. Improving trends confirm that your lifestyle interventions are working.

3
Prioritize Dietary Interventions

Reduce refined carbohydrates, added sugars, and processed foods. Increase fiber, healthy fats, and protein. Consider time-restricted eating. These dietary changes are the most powerful tools for reversing insulin resistance.

4
Exercise Consistently

Both resistance training and aerobic exercise independently improve insulin sensitivity through different mechanisms. Aim for 3-4 sessions of resistance training and 150+ minutes of Zone 2 cardio per week. Walking after meals can also significantly blunt glucose spikes.

Why I built this guide.

"Type 2 diabetes is a preventable disease when caught early. Fasting insulin is the most important test your doctor probably is not ordering."

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