⚠️ This information does not constitute medical advice. It is compiled expert opinion for educational purposes. Your doctor knows you best. Consult your doctor for specific questions about your personal lab results.
Most of us get a standard panel of blood tests — cholesterol, glucose — every year or two at a physical. We assume that if any result is too high or low, the doctor will say something. No news is good news.
This is not the path to optimal health.
We believe you should be empowered to make sense of those results yourself — to know what the values tell you about what's going on in your body, and to have a sense of not just the standard ranges, but the optimal levels and how they interact with each other.
A note on sourcing: This guide reflects the views of several early Levels advisors — physicians and researchers who helped shape our thinking when Levels was getting started. Their perspectives are opinionated, sometimes contrarian, and worth reading as a counterweight to mainstream guidance.
For more granular evidence and voices from lipid specialists like Ronald Krauss, MD and Kevin Maki, PhD, see our Biomarker Guides and the relevant podcast episodes, linked throughout.
We put together this guide by talking to eight advisors who are experts in metabolic health. The point isn't to give you more challenging numbers to aim for, but to help you understand that blood test markers are complex, they represent interrelated systems in your body, and they're worth investing time to understand. None of these markers exists in isolation.
The Advisors
Ben Bikman, PhD
Associate Professor of Cell Biology & Physiology, Brigham Young University · Director, Laboratory of Obesity and Metabolism · Author, Why We Get Sick
Dom D'Agostino, PhD
Associate Professor, Dept. of Molecular Pharmacology & Physiology, USF Morsani College of Medicine · Research Scientist, Institute for Human and Machine Cognition
Dr. Sara Gottfried
Director of Precision Medicine, Marcus Institute of Integrative Health · Clinical Assistant Professor, Dept. of Integrative Medicine & Nutritional Sciences, Thomas Jefferson University
Dr. Mark Hyman
Founder & Senior Advisor, Cleveland Clinic Center for Functional Medicine · Co-founder & Chief Medical Officer, Function Health · 16-time New York Times bestselling author
Dr. Rob Lustig
Professor Emeritus of Pediatrics, Division of Endocrinology, UCSF · Neuroendocrinologist specializing in childhood obesity, metabolic health, and nutrition
Dr. Molly Maloof
Concierge precision medicine physician · Founder & CEO, Adamo Bioscience · Former lecturer on healthspan, Stanford University School of Medicine · Author, The Spark Factor
Dr. Casey Means
Co-founder of Levels · Stanford-trained physician · Associate Editor, International Journal of Disease Reversal and Prevention
Dr. David Perlmutter
Board-certified neurologist · Associate Professor, University of Miami Miller School of Medicine · Director of Neuroscience Research, Bryan Therapeutics · Author, Grain Brain
Quick Reference
Expert consensus: optimal targets
| Marker | Standard range | Optimal target |
|---|
| hsCRP | < 2.0 mg/L | < 1.0 mg/L |
| HbA1c | < 5.7% | < 5.5% (some: < 5.0%) |
| Fasting glucose | < 100 mg/dL | 70–85 mg/dL |
| Fasting insulin | < 25 mIU/L | 2–6 μIU/mL |
| LDL-C | < 130 mg/dL | < 100 mg/dL (context-dependent) |
| Triglycerides | < 150 mg/dL | < 100 mg/dL |
| HDL-C | > 45 mg/dL | > 60 mg/dL |
| Total cholesterol | < 200 mg/dL | < 180 mg/dL |
| TC/HDL ratio | < 5:1 | < 3.5:1 (ideally < 2:1) |
| TG/HDL ratio | — | < 1:1 |
| Post-meal glucose | < 140 mg/dL | < 110–115 mg/dL |
| HOMA-IR | 0.5–1.4 | < 1.0 |
Marker 01
High-sensitivity C-reactive protein (hsCRP)
A protein made by the liver that rises in blood concentration when you have inflammation — a general signal of metabolic dysfunction, infection, or chronic disease.
Standard range
< 2.0 mg/L lower risk
> 2.0 mg/L higher risk
Optimal target
< 1.0 mg/L
(some: < 0.5 mg/L)
Elevated CRP signals that inflammation is present — and inflammation is both a driver and a consequence of metabolic dysfunction. All features of metabolic syndrome are associated with increased CRP. High BMIs, abdominal obesity, and increasing insulin resistance are all linked to higher levels. Think of it as a canary: its elevation tells you something worth investigating, even before more specific tests flag a problem.
Dr. Mark HymanCleveland Clinic / Functional Medicine
"The easiest way to measure hidden inflammation in the body is C-reactive protein. CRP is significantly elevated in most people with diabesity (insulin resistance). As the diabesity gets better, the inflammation goes down."
Dom D'Agostino, PhDUniversity of South Florida
"High CRP levels are found in those with obesity, heart disease, diabetes, Alzheimer's disease, leaky gut, infection, cancer, sleep disorders, and other states of chronic inflammation. All features of metabolic syndrome are associated with increased CRP."
Dr. Casey MeansCo-founder, Levels
"Inflammation is a key driver of metabolic dysfunction, and metabolic dysfunction leads to further inflammation. hsCRP can give you a signal of how much general inflammation is going on in the body."
Ben Bikman, PhDBrigham Young University
"Whether from hypertrophic adipocytes, arterial foam cells, or simple white blood cells doing their job, hsCRP is a solid indicator of subclinical systemic inflammation — a canary in the coal mine for insulin resistance, atherogenesis, and more."
Dr. Rob LustigUCSF
"hsCRP is an 'acute-phase reactant.' A virus or other acute illness can raise it irrespective of your metabolic status — which makes it sensitive but not specific for metabolic inflammation."
Dom D'Agostino, PhD
Ideal: < 1.0 mg/L · Average: 1.0–3.0 mg/L · High: 3.0–6.0 mg/L · Pathologically high: > 6.0 mg/L
Dr. Molly Maloof
Shoot for < 0.5 mg/L.
Dr. Sara Gottfried
I aim for < 0.5 mg/L in most of my healthy patients who are not elite athletes.
Dr. Mark Hyman
Less than 1.0 mg/L is ideal.
Dr. Rob Lustig
The lower the better; try for less than 1.0 mg/L.
Levels synthesis
< 1.0 mg/L is the target; some experts push to < 0.5 mg/L. Elevated hsCRP in the absence of infection is one of the clearest signals of underlying metabolic dysfunction — and one of the most responsive to lifestyle improvement.
Podcast · A Whole New Level
Immune Health: Inflammation, White Blood Cells, and Resilience
89 min · Nov 2025 · #285
Immune resilience isn't the same as immune strength. Why chronic inflammation is a metabolic problem, how the immune system ages, and what daily habits shift your baseline.
Marker 02
Hemoglobin A1c (HbA1c)
A way to measure blood glucose averages over the preceding three months, expressed as the percentage of hemoglobin molecules that have been glycated.
Standard range (ADA)
< 5.7% normal
5.7–6.4% prediabetes
≥ 6.5% diabetes
Optimal target
< 5.5%
(some: < 5.0–5.2%)
HbA1c captures a three-month average of blood glucose — more stable than a single fasting reading and better at catching chronic hyperglycemia. It's the recommended diagnostic for prediabetes and diabetes. But it has meaningful limitations: it misses glycemic variability entirely, and by the time it rises, metabolic dysfunction is typically already well advanced.
Dr. Rob LustigUCSF
"HbA1c is the blood test that assesses glucose control over three months. The problem is that by the time it rises, the horse is out of the barn — it's one of the last things to change with metabolic dysfunction."
Dr. Mark HymanCleveland Clinic
"HbA1c tells you if your overall blood sugar has been high over the previous six weeks. Even in the face of normal fasting blood sugar your HbA1c can be high, because it measures your average sugar, including the effects of all the food you eat throughout the day."
Dr. Molly MaloofFunctional Medicine
"As a diagnostic, HbA1c has a sensitivity of only 60%, meaning 40% of patients with impaired fasting glucose will go under-diagnosed. It also does not address glycemic variability. One study found HbA1c has a false negative rate of 64.9% for prediabetes and 75.1% for diabetes compared to fasting glucose and oral glucose tolerance tests."
Dr. Sara GottfriedMarcus Institute / Jefferson Health
"HbA1c is useful as a three-month summary of glucose excursions. Its limitations: it doesn't reflect day-to-day variability, and can be falsely low in patients with nighttime hypoglycemia — something I see often in perimenopausal and menopausal women."
Ben Bikman, PhDBrigham Young University
"A person with robust and long-lived red blood cells is more likely to have some glycosylated even if glucose levels are normal — a false positive. Conversely, someone with more fragile RBCs but high glucose would have an artificially low A1c — a false negative. RBC longevity matters."
Dom D'Agostino, PhD
Optimal: < 5.0% (common with low-carb diet or calorie restriction) · Normal: < 5.7%
Dr. Molly Maloof
Optimal: 4.5–5.3%
Dr. Sara Gottfried
I like < 5.2%. In patients with prediabetes, I'm aiming for < 5%.
Dr. Mark Hyman
Ideally less than 5.5%.
Dr. Rob Lustig
I like to see 5.5% or less.
Dr. David Perlmutter
The average A1c should ideally be in the range of 5.2%.
Levels synthesis
Aim for < 5.5%; several experts target 5.0–5.2% as truly optimal. Don't rely on HbA1c alone — it misses glycemic variability and has real sensitivity limitations. Pair it with fasting glucose and, ideally, fasting insulin.
Note: HbA1c can be falsely skewed by hemoglobin variants common in people of African, Mediterranean, or Southeast Asian descent, as well as anemia, blood loss, high triglycerides, and certain medications.
Podcast · A Whole New Level
Glucose Metabolism: HbA1c, Insulin Resistance, and Better Energy
105 min · Oct 2025 · #284
HbA1c tells you averages — insulin tells you direction. How glucose metabolism works, why insulin resistance precedes blood sugar abnormalities, and what to track instead.
Marker 03
Fasting Glucose
A measure of your blood sugar levels unaffected by a recent meal — the most commonly ordered metabolic test, and one of the last to rise as dysfunction develops.
Standard range
< 100 mg/dL normal
100–125 prediabetes
≥ 126 diabetes
Optimal target
70–85 mg/dL
Fasting glucose is useful but tells an incomplete story on its own. The body works hard to maintain normal glucose by producing more and more insulin — so by the time glucose rises to 100, insulin resistance is typically well underway. Multiple studies show cardiovascular and metabolic risk increases even within the "normal" range. View fasting glucose alongside fasting insulin for a fuller picture.
Dr. Rob LustigUCSF
"Every practitioner gets a fasting glucose on all their adult patients, looking for type 2 diabetes. Yet this is the single worst parameter to measure, because it's the last thing to change. Once fasting glucose rises over 100 mg/dL, metabolic syndrome is in full force. But a fasting blood glucose of 90 mg/dL is already questionable."
Dr. Mark HymanCleveland Clinic
"There are six stages of diabesity. By the time fasting blood sugar is higher than 90 or 100 mg/dL, we're already far down the progression of insulin resistance — this is stage four of six."
Dr. Casey MeansLevels
"Multiple research studies show that as fasting glucose increases, there is an increased risk of health problems like diabetes and heart disease — even if it stays within the normal range."
Ben Bikman, PhDBrigham Young University
"Blood glucose matters — chronically high levels will damage blood vessels and nerves through several distinct mechanisms. However, to be most valuable, glucose needs to be viewed dynamically: how does it rise and fall in response to diet, exercise, sleep?"
Dom D'Agostino, PhD
Optimal: < 90 mg/dL · Normal: < 100 mg/dL · Pre-diabetic: 100–125 mg/dL
Dr. Molly Maloof
Optimal: 72–89 mg/dL · Increased prediabetes risk: 90–100 mg/dL
Dr. Sara Gottfried
I target 70–85 mg/dL, or 65–85 mg/dL in patients in ketosis.
Dr. Mark Hyman
Fasting blood sugar should be less than 85 mg/dL.
Dr. Casey Means
Aim for 72–85 mg/dL. Research shows increased risk even within the normal range as glucose climbs.
Levels synthesis
Aim for the 70s to low 80s. A fasting glucose of 90 mg/dL is already a yellow flag for many experts. By 100, insulin resistance is typically in full force — which is why fasting insulin is a more sensitive early warning.
Podcast · A Whole New Level
Insulin Resistance and How It Affects Each of Us Differently
42 min · Apr 2022 · #102
Insulin resistance doesn't look the same in everyone. Why women, South Asians, and lean individuals hit dysfunction at different thresholds — and what that means for testing.
Marker 04
Fasting Insulin
Insulin levels unaffected by a recent meal. Rises before fasting glucose does — making it the earlier and more sensitive warning sign for insulin resistance.
Why it mattersThe body will do everything it can to maintain normal fasting glucose — including producing more and more insulin. That's insulin resistance. Measuring fasting insulin reveals how hard the pancreas is working, even when glucose looks fine. This dysfunction can advance for years, even decades, before glucose rises enough to be flagged. Most conventional panels don't include fasting insulin — which is a significant gap.
Dr. Rob LustigUCSF
"The body will do everything it can to maintain a fasting serum glucose below 100 mg/dL, including increasing insulin — that's insulin resistance. Many medical societies don't advocate getting a fasting insulin level. They cite cost (~$15) and reproducibility. But it's not about obesity; it's about metabolic health. If you don't measure fasting insulin, you're missing all the normal-weight metabolically ill people."
Ben Bikman, PhDBrigham Young University
"We can have a scenario where a person is steadily becoming more and more insulin resistant for years — even decades — while glucose remains in the normal range. This is why so many people with insulin resistance are undiagnosed: we look at it wrong. For every one micro unit increase in fasting blood insulin, there is approximately a 20% increase in insulin resistance."
Dr. Mark HymanCleveland Clinic
"The second stage of diabesity is elevated levels of fasting insulin with a perfectly normal blood sugar level. By the time fasting glucose rises, fasting insulin has been high for a long time."
Dr. Mark Hyman
2–5 IU/dL optimal · > 10 IU/dL concerning · > 15 IU/dL significantly elevated
Dr. Rob Lustig
< 10 μU/mL target · > 15 μU/mL = significant insulin resistance
Dom D'Agostino, PhD
Optimal: 2–6 μIU/mL
Dr. David Perlmutter
Target 8 or lower.
Ben Bikman, PhD
≤ 10 μIU/mL = insulin sensitive · 11–20 = warning range · 20+ = strong insulin resistance
Levels synthesis
Optimal is likely 2–6 μIU/mL. Fasting insulin is one of the most valuable and most underused tests available — it can reveal metabolic dysfunction years before glucose rises. If your standard panel doesn't include it, ask for it explicitly.
Podcast · A Whole New Level
Understanding Blood Sugar Levels, Insulin Resistance, and Impact on Chronic Diseases
80 min · Apr 2023 · #209
Insulin is the energy-storage hormone — when cells stop responding, everything breaks. How to test for resistance early, why rising insulin precedes rising glucose by years.
Marker 05
LDL Cholesterol (LDL-C)
Cholesterol carried by low-density lipoproteins. Often called "bad" cholesterol — an important marker, but the standard test measures cholesterol mass rather than the particle count that better predicts risk.
Standard range
< 130 mg/dL general
< 100 high risk
< 70 very high risk
Optimal target
< 100 mg/dL
(< 70 per some experts)
LDL matters — but the standard LDL-C test measures cholesterol mass, not particle count. What drives plaque buildup is primarily small dense LDL (type B) particles, not large buoyant ones (type A). Two people with identical LDL-C numbers can have very different cardiovascular risk depending on particle composition. More than 50% of people who arrive at an ER with a heart attack have "normal" cholesterol.
Dr. Rob LustigUCSF
"There are two different LDLs. Large buoyant (type A) LDL — increased by dietary fat and reduced by statins — is cardiovascularly neutral. Small dense (type B) LDL is predictive of heart attack risk. Statins lower type A because it's 80% of total LDL — but they're not doing anything to type B, the problematic particle. Small dense LDL rises from refined carbohydrates and sugar, not dietary fat."
Dr. Mark HymanCleveland Clinic
"We measure and treat LDL because we have drugs to lower it — not because it's the most important marker. More than 50% of people who show up at the ER with heart attacks have normal cholesterol — but they have small LDL particles caused by insulin resistance. The NMR lipid test, which measures particle size, is one of the most essential tests for evaluating cardiovascular risk."
Dom D'Agostino, PhDUniversity of South Florida
"Risk from elevated LDL is meaningful in the context of other elevated biomarkers — triglycerides, HbA1c, hsCRP. In isolation, particularly in those on a high-fat low-carb diet, it tells an incomplete story."
Ben Bikman, PhDBrigham Young University
"LDL is a very misunderstood molecule. The degree to which it contributes to heart disease is very unclear. More clear is its role in immunity — LDL has the capacity to bind and neutralize infectious, pro-inflammatory pathogens. People with the lowest LDL levels have a significantly higher risk (5×) of frequent fevers and serious infections."
Dr. Rob Lustig
If LDL-C is below 100, the small dense fraction can't be high enough to be harmful. If over 300, suspect familial hypercholesterolemia. For 100–300, look at triglyceride level: if > 150 mg/dL, that's metabolic syndrome until proven otherwise.
Dom D'Agostino, PhD
Optimal: < 150 mg/dL (lower risk for cardiovascular disease)
Dr. Molly Maloof
Optimal: < 100 mg/dL · High: 130–190 mg/dL · Critically high: > 191 mg/dL
Dr. Sara Gottfried
< 70 mg/dL
Dr. Mark Hyman
< 70 mg/dL is optimal — but it depends on particle size and number, which LDL-C alone cannot tell you.
Levels synthesis
The absolute LDL-C number is less informative than particle size and count. Look at ApoB or NMR fractionation if available — these are stronger predictors. Use the triglyceride-to-HDL ratio as a practical surrogate for small dense LDL burden. Target < 100 mg/dL overall; < 70 is considered optimal by some, but context matters. See our
ApoB guide for more.
On ApoB: ApoB testing — one protein per atherogenic particle — is increasingly recognized as a stronger predictor of cardiovascular risk than LDL-C. It's not significantly more expensive and is worth requesting alongside a standard lipid panel.
Podcast · A Whole New Level
Why Your LDL Score Doesn't Tell the Whole Story
60 min · Mar 2026 · #294
LDL-C alone won't tell you your real risk. What ApoB, small dense LDL, and Lp(a) reveal that a standard cholesterol panel misses — and what metabolic dysfunction has to do with it.
Marker 06
Triglycerides
Fat stored in cells when calories go unused, carried mainly by VLDL — which become LDL after releasing their triglycerides. One of the most direct markers of dietary quality and metabolic syndrome.
Standard range
< 150 mg/dL
Optimal target
< 100 mg/dL
(some: < 80 or < 50)
Triglycerides rise primarily with excess refined carbohydrate and sugar intake — not dietary fat — and they’re tightly linked to insulin resistance. When VLDL unloads its triglycerides at adipose tissue, it becomes the small dense LDL fraction that contributes most to cardiovascular risk. Triglycerides are also one of the most responsive markers to dietary change.
Dr. Rob LustigUCSF
"The #1 risk factor for heart disease isn't LDL-C — it's the insulin resistance of metabolic syndrome, of which triglycerides are a much better marker. The main reason for high triglycerides isn't dietary fat; it's refined carbohydrates and sugars. The serum triglyceride, unloaded of its fat at adipose tissue, becomes the small dense LDL."
Dom D'Agostino, PhDUniversity of South Florida
"High serum triglycerides indicate metabolic syndrome and non-alcoholic fatty liver disease and also increase the risk of acute pancreatitis. They are an indication that excess calories are being consumed, typically in the form of sugar and fructose."
Dr. Mark HymanCleveland Clinic
"Patients with diabesity often have normal LDL and total cholesterol, but very high triglycerides and very low HDL. Triglycerides of 300 and HDL of 30 concerns me far more than total cholesterol of 300 with triglycerides of 60 and HDL of 80."
Dr. Casey MeansLevels
"Triglycerides are a good marker of dietary quality. I have seen them drop more than 80 mg/dL in less than one month in patients who eliminate refined and processed foods."
Dom D'Agostino, PhD
Optimal: < 100 mg/dL · Normal: 100–150 mg/dL · High risk: > 150 mg/dL
Dr. Molly Maloof
Optimal: < 80 mg/dL · Better: < 100 mg/dL · Normal: < 150 mg/dL · Borderline-high: 150–199 mg/dL
Dr. Sara Gottfried
< 150 mg/dL minimum; I aim for < 100 mg/dL or even < 50 mg/dL in patients optimizing metabolic health.
Dr. Mark Hyman
< 100 mg/dL; ideally under 70 mg/dL.
Dr. David Perlmutter
< 50 mg/dL would be ideal.
Levels synthesis
< 150 mg/dL is the minimum; optimal is < 100 mg/dL, with several experts pushing for < 80 or even < 50. High triglycerides paired with low HDL are among the clearest signals of insulin resistance and metabolic syndrome.
Marker 07
HDL Cholesterol (HDL-C)
High-density lipoproteins carry cholesterol back to the liver for breakdown. Often called "good" cholesterol — though functionality matters as much as the raw number.
Optimal target
> 60 mg/dL
(toward 90 is better)
HDL goes down in the setting of insulin resistance — it’s one of the defining features of metabolic syndrome. Low HDL is a meaningful cardiovascular risk signal, often paired with high triglycerides in people who are metabolically unwell. Higher HDL generally signals better metabolic health, though the relationship is more nuanced than the simple "good cholesterol" label: functionality — not just quantity — is what matters.
Dom D'Agostino, PhDUniversity of South Florida
"Epidemiological studies have shown that higher concentrations of HDL (> 60 mg/dL) are associated with reduced cardiovascular risk. For a given level of LDL, the risk of heart disease increases 10-fold as HDL varies from high to low."
Dr. Rob LustigUCSF
"If HDL is over 60 mg/dL, it almost doesn't matter what the other cholesterol fractions are — it's a sign of good cardiovascular health. If HDL is under 40 mg/dL (men) or under 50 mg/dL (women), predisposition to heart disease is much higher."
Dr. Sara GottfriedMarcus Institute / Jefferson Health
"The emerging narrative is that HDL is far more heterogeneous than previously understood. For HDL to be cardioprotective, it must be functional. Increased intake of virgin olive oil, nuts, legumes, whole grains, and fish improves HDL functionality."
Dom D'Agostino, PhD
Optimal: > 60 mg/dL · Normal: 50–60 mg/dL · Low: < 50 mg/dL · High risk: < 40 mg/dL
Dr. Molly Maloof
Aim for 50–90 mg/dL.
Dr. Mark Hyman
> 60 mg/dL is optimal.
Levels synthesis
HDL should be above 60 mg/dL, with higher being generally better up toward 90 mg/dL. Low HDL — particularly when paired with high triglycerides — is a strong signal of insulin resistance.
Marker 09
Total Cholesterol to HDL Ratio
Total cholesterol divided by HDL — a better predictor of cardiovascular risk than either number in isolation.
Standard range
< 5:1 most targets
< 3.5:1 very good
Optimal target
< 3.5:1
(ideally < 2:1)
For a given level of total cholesterol, heart disease risk increases 10-fold as HDL drops from high to low. Men have double the average risk if their ratio reaches 9.6:1, and roughly half the average risk at 3.4:1. This ratio contextualizes total cholesterol far better than the raw number — though the triglyceride-to-HDL ratio is an even stronger predictor.
Dr. Mark HymanCleveland Clinic
"LDL cholesterol is a very bad predictor of heart disease risk when compared with the total cholesterol-to-HDL ratio. And this is not as good a predictor as the triglyceride-to-HDL ratio — which is the best way to check for insulin resistance other than the insulin response test."
Dom D'Agostino, PhDUniversity of South Florida
"For a given level of total cholesterol, the risk of heart disease increases 10-fold as the HDL varies from high to low. Men have double the risk if their ratio reaches 9.6:1, and roughly half the average risk with a ratio of 3.4:1."
Dom D'Agostino, PhD
Optimal: < 2:1 · Normal: 2–5:1 · High risk: > 5:1
Dr. Molly Maloof
Most healthcare providers want < 5:1. < 3.5:1 is very good.
Dr. Mark Hyman
Target < 3:1.
Levels synthesis
Keep the total cholesterol-to-HDL ratio below 3.5:1; optimally below 2:1. A useful ratio — though the triglyceride-to-HDL ratio below is generally a stronger cardiovascular and insulin resistance signal.
Podcast · A Whole New Level
Why You Need a Calcium Score to Know Your Real Heart Risk
54 min · Feb 2026 · #292
A coronary artery calcium score predicts heart events better than any blood test. Why most doctors don't order it, what a score of zero means, and when rising calcium is dangerous.
Marker 10
Triglyceride to HDL Ratio
Triglycerides divided by HDL — widely considered the best readily available surrogate for insulin resistance and small dense LDL particle burden. Pay close attention to this one.
Standard range
No universal standard
> 2:1 suggests dysfunction
Optimal target
< 1:1
(ideally < 0.5:1)
Triglycerides go up and HDL goes down together as insulin resistance develops — so the ratio amplifies the signal from both simultaneously. According to research published in Circulation, the triglyceride-to-HDL ratio is the most powerful predictor of heart attack risk among standard lipid markers, with a high ratio associated with a 16-fold increase in risk. It's also the best available surrogate for small dense LDL without needing an NMR test.
Dr. Mark HymanCleveland Clinic
"According to a paper published in Circulation, the most powerful test to predict your risk of a heart attack is the ratio of your triglycerides to HDL. If the ratio is high, your risk for a heart attack increases 16-fold — or 1,600 percent. This is because triglycerides go up and HDL goes down with insulin resistance simultaneously."
Dr. Rob LustigUCSF
"The triglyceride-to-HDL ratio is the best biomarker of small dense LDL, the best biomarker of cardiovascular disease, and the best surrogate marker for insulin resistance and metabolic syndrome."
Dom D'Agostino, PhDUniversity of South Florida
"The triglyceride-to-HDL cholesterol ratio has shown the strongest association with cardiovascular disease of any lipid marker or ratio."
Dom D'Agostino, PhD
Optimal: < 1:1 · Normal: 1–2:1 · High risk: > 2:1
Dr. Molly Maloof
< 1:1 = insulin-sensitive (optimal) · > 1.9:1 = early insulin resistance · > 2.9:1 = significant insulin resistance
Dr. Mark Hyman
Optimal: < 4:1. Abnormal: > 4:1.
Dr. Rob Lustig
For reasons that are unclear, race matters: > 2.5:1 in Caucasians or > 1.5:1 in African Americans correlates with metabolic syndrome.
Levels synthesis
This is the ratio to prioritize. Lower is better. > 2.5:1 in Caucasians or > 1.5:1 in African Americans correlates with metabolic syndrome. Ideal target: < 1:1.
Marker 11
Post-Meal Glucose
Blood sugar measured at peak or two hours after eating — capturing glycemic response that fasting glucose misses entirely.
Standard range (ADA)
< 140 mg/dL at 2 hours
Optimal target
< 110–115 mg/dL at any post-meal point
Not everyone with prediabetes has elevated fasting glucose — some people’s dysfunction shows up primarily in postprandial response. Repeated glucose spikes are an important contributor to atherosclerosis through endothelial dysfunction. Levels above 135 mg/dL are associated with large vessel damage; above 160 mg/dL, small vessel damage begins. A continuous glucose monitor gives you the clearest view of this dynamic.
Dom D'Agostino, PhDUniversity of South Florida
"Post-prandial glycemia is an important contributing factor in the development of atherosclerosis through endothelial dysfunction. Repeated hyperglycemic spikes are important contributors to cardiovascular disease."
Dr. Molly MaloofFunctional Medicine
"Post-meal peaks above 160 mg/dL will cause glucose to spill into urine through the kidneys. Above 135 mg/dL it will damage blood vessels."
Dr. Sara GottfriedMarcus Institute / Jefferson Health
"There are many roads to metabolic dysfunction. Not all people with prediabetes have high fasting glucose, so we want to look at the full dynamic range, including after meals."
Dr. Mark Hyman
30-minute, 1-hour, and 2-hour glucose should not rise above 110 mg/dL; some say 120 mg/dL.
Dr. Molly Maloof
Most healthy: < 110 mg/dL after meals. Vascular damage begins at > 135 mg/dL; glucose spills into urine at 160–180 mg/dL.
Dom D'Agostino, PhD
Optimal: < 120 mg/dL · Normal: < 160 mg/dL · High-risk: > 180 mg/dL
Dr. Sara Gottfried
Mainstream cutoff is < 140 at 2 hours. I like < 115 mg/dL, and I also assess glucotype — how spiky a person is across the day.
Levels synthesis
Aim to keep post-meal glucose below 110–115 mg/dL at any point. Levels above 135 mg/dL are associated with large vessel damage; above 160 mg/dL, small vessel damage. A CGM is the most practical tool for tracking this in real time.
Marker 12
HOMA-IR
Homeostatic Model Assessment for Insulin Resistance — calculated from fasting insulin × fasting glucose ÷ 405. A single number that estimates how well your insulin is working.
Standard range
0.5–1.4 generally healthy
If you have both fasting glucose and fasting insulin, HOMA-IR gives you a composite number reflecting insulin sensitivity that you can track over time. It captures the relationship between how much insulin the pancreas is producing and how much work that insulin is actually doing. The fact that it requires both inputs is itself a practical argument for always ordering fasting insulin alongside fasting glucose.
Dr. Molly MaloofFunctional Medicine
"If you know your fasting blood glucose and fasting insulin, the HOMA-IR equation can tell you how insulin sensitive or insulin resistant you are. If your fasting blood sugar is 5.7 mmol/L but your insulin is over 12 μU/mL, you are insulin resistant. If it's under 9 μU/mL, you are likely insulin sensitive."
Dom D'Agostino, PhDUniversity of South Florida
"Insulin resistance precedes type 2 diabetes and would help to manage or even prevent it from happening. HOMA-IR is a valuable equation-based measurement to determine insulin sensitivity from paired fasting plasma glucose and insulin."
Dr. Molly Maloof
Optimal insulin sensitivity: < 1 · Early insulin resistance: > 1.9 · Significant insulin resistance: > 2.9
Dom D'Agostino, PhD
Optimal: < 0.5 · Normal: 0.5–1.4 · High risk: > 1.4 · Very high risk: > 2.9
Dr. Rob Lustig
< 2.0 is excellent · 4.0 is average · Higher than 4.0 means trouble.
Dr. Sara Gottfried
< 1 indicates an insulin-sensitive state.
Levels synthesis
Aim for HOMA-IR < 1.0. This composite operationalizes fasting glucose and insulin together — and requiring both inputs is itself a reason to always order fasting insulin alongside glucose.
Calculate yours →See your own numbers — and what moves them
Levels pairs at-home blood testing for these markers with a continuous glucose monitor, so you can see where you stand against the optimal targets above and track your progress over time.
Get started →
