What they are
Triglycerides are fat in transit
A triglyceride is the form in which the body stores and transports most of its fat. The molecule is made of one glycerol backbone with three fatty acids attached, hence the name. When you eat fat, most of it is packaged into triglycerides inside intestinal cells and shipped through the bloodstream to be either burned for energy or stored. When you eat more carbohydrate than the body needs in the moment, the liver converts the excess into triglycerides through a process called de novo lipogenesis, and then sends them out into circulation as well.[1]
This is the first thing that surprises most people about triglycerides. The number on a lipid panel reflects fat in transit through the blood, but a large fraction of that fat was assembled by the liver out of carbohydrate, not eaten as fat in the first place. A diet high in refined carbohydrate and added sugar reliably elevates fasting triglycerides even in the absence of meaningful fat consumption. That single observation explains why low-fat diets that replaced fat with refined starch and sugar so often produced rising triglycerides rather than falling ones.
The numbers, in plain English
What the normal range actually says
A standard fasting lipid panel categorizes triglycerides into roughly these bands (units are mg/dL, as used in the United States):
- Normal: below 150 mg/dL
- Borderline high: 150 to 199 mg/dL
- High: 200 to 499 mg/dL
- Very high: 500 mg/dL and above
Outside the United States, the same panel is usually reported in mmol/L. The conversion factor is 0.0113. So 150 mg/dL is approximately 1.7 mmol/L. The bands are otherwise identical.
There is an important nuance the "normal" label hides. A triglyceride number under 150 mg/dL is the official cutoff for "normal," but the metabolic literature has converged on a much more demanding optimal range. A fasting triglyceride below 100 mg/dL (about 1.1 mmol/L) is the genuine optimum. Numbers between 100 and 150 are technically normal but increasingly recognized as a sign of early insulin resistance. Numbers between 75 and 100 are characteristic of metabolically healthy populations. Numbers below 75 are common in plant-based eaters, in regular fasters, and in trained endurance athletes.
This matters because a person told their triglycerides are "normal" at 140 mg/dL may be reassured at the moment they should be informed. The lab range is a population threshold for clinical concern, not a target for health.
Why this number is so informative
Triglycerides as a metabolic mirror
Of all the lines on a standard lipid panel, fasting triglycerides are the most responsive to short-term metabolic changes and the most informative about insulin sensitivity. Total cholesterol moves slowly and is heavily influenced by genetics. LDL cholesterol is informative but takes months to shift meaningfully. HDL is slow to respond. Triglycerides, by contrast, can change measurably within weeks of an eating-pattern shift, and they correlate tightly with how well the body is handling carbohydrate, fat storage, and metabolic load.[2][T2]
The ratio of triglycerides to HDL cholesterol is particularly useful as a proxy for insulin resistance. A triglyceride-to-HDL ratio under 2 (using mg/dL) is a strong sign of metabolic flexibility. A ratio over 3.5 is a strong sign of insulin resistance regardless of where any single number sits in isolation. This ratio is calculable from any standard lipid panel and is one of the most overlooked metabolic signals in routine bloodwork.
What raises them, in order of impact
The inputs that move the number up
Triglycerides rise reliably in response to:
- Refined carbohydrate and added sugar, particularly fructose, which is processed almost entirely by the liver and drives de novo lipogenesis directly.
- Alcohol, which the liver prioritizes for processing and which suppresses fat oxidation. Even modest regular alcohol use produces measurable triglyceride elevation in most people.
- Recent eating. A triglyceride number drawn within hours of a fat-containing meal can be temporarily elevated by 50 to 100 percent. Standard lipid panels are drawn fasting (10 to 12 hours) specifically to avoid this.
- Insulin resistance and visceral adiposity, which together raise the rate at which the liver releases triglycerides into circulation.
- Sedentary behavior, which reduces skeletal muscle's uptake and oxidation of circulating fat.
- Untreated hypothyroidism, certain medications (beta blockers, thiazide diuretics, oral estrogens, some antiretrovirals), and pregnancy.
What lowers them, in order of impact
The inputs that move the number down
Triglycerides fall reliably in response to:
- Reducing refined carbohydrate and added sugar. This is the single highest-leverage dietary change for elevated triglycerides. Many people see 30 to 50 percent drops within weeks of this change alone.
- Plant-based eating patterns, which combine low refined-carbohydrate density with high fiber, which slows fat absorption and improves insulin sensitivity.
- Time-restricted eating, which extends the daily fasting window during which the liver clears circulating fat.
- Daily moderate movement, especially after meals, which improves muscle uptake of triglycerides for oxidation.
- Reducing or eliminating alcohol. Often produces a 20 to 40 percent triglyceride drop in heavy drinkers within weeks of cessation.
- Omega-3 intake, particularly EPA and DHA from fatty fish or algal oil. Has a modest direct lowering effect, especially at higher doses (2 to 4 grams per day) used clinically for elevated triglycerides.
- Treating underlying insulin resistance or thyroid dysfunction when present.
When triglycerides are very high
The clinical concern threshold
Triglycerides above 500 mg/dL are a separate clinical category. At this level the risk of acute pancreatitis rises significantly, and aggressive intervention is warranted. People in this range should be working with a clinician. The first-line interventions remain dietary (sharp reduction of refined carbohydrate, alcohol elimination, weight loss) but may be supplemented with pharmacological options (fibrates, high-dose omega-3, niacin in selected cases) depending on the clinical picture.
For the much more common situation of triglycerides between 150 and 300 mg/dL, the framework is the same one developed throughout The Health Protocol. The number is a signal, not a disease. It is responding to the inputs the body is receiving. Change the inputs and the number changes.[3][T1]
Where this lives in The Health Protocol
Mapped to the book
Triglycerides are part of the larger biomarker conversation in Chapters V and VI of The Health Protocol, which cover metabolic health and the cardiovascular consequences of metabolic dysfunction. The dietary patterns that move triglycerides are developed throughout Module 2 (Nourishment by Design) and the metabolic logic is the spine of Module 3 of the seminar (Metabolic Coherence).
Hunger is not simply a matter of willpower, and satiety is not a moral achievement.
The Health Protocol · Chapter V · p. 90
Primary references from The Health Protocol bibliography
These papers are cited in the canonical bibliography of The Health Protocol. Full bibliography at thejourneybeginswithin.com/health/references/.
- [T1]Satija A, Bhupathiraju SN, Spiegelman D, et al. Healthful and unhealthful plant-based diets and the risk of coronary heart disease in U.S. adults. Journal of the American College of Cardiology. 2017;70(4):411 to 422. The study distinguished healthful from unhealthful plant-based patterns and found sharply different coronary risk associations. TJBW [4.11]
- [T2]Koch M, Hjorth MF, Sjodin A, et al. Vegetarian or vegan diets and blood lipids: a meta-analysis of randomized trials. European Heart Journal. 2023;44(28):2609 to 2622. Vegetarian and vegan dietary patterns were associated with lower total cholesterol, low density lipoprotein cholesterol, and apolipoprotein B. TJBW [4.12]
Additional references cited in this article
All claims above are sourced to peer-reviewed literature. The numbered list below corresponds to the inline citations. The full bibliography for The Health Protocol is available at thejourneybeginswithin.com/health/references/.
- [1]Michael Miller et al.. Triglycerides and cardiovascular disease: a scientific statement from the American Heart Association. Circulation. 2011;123(20):2292 to 2333. AHA scientific statement on triglycerides and cardiovascular risk: optimal fasting triglycerides below 100 mg/dL, with the triglyceride/HDL ratio as a useful proxy for insulin resistance. doi.org/10.1161/CIR.0b013e3182160726
- [2]Mohammad G. Saklayen. The global epidemic of the metabolic syndrome. Current Hypertension Reports. 2018;20(2):12. Review of the global prevalence of metabolic syndrome (estimated one-quarter of adults worldwide) and its components (visceral adiposity, dyslipidemia, hypertension, insulin resistance). doi.org/10.1007/s11906-018-0812-z
- [3]Michael J. Wilkinson et al.. Ten-hour time-restricted eating reduces weight, blood pressure, and atherogenic lipids in patients with metabolic syndrome. Cell Metabolism. 2020;31(1):92 to 104.e5. Twelve-week trial of 10-hour time-restricted eating in patients with metabolic syndrome producing measurable reductions in weight, blood pressure, and atherogenic lipid markers. doi.org/10.1016/j.cmet.2019.11.004