What it measures.
Triglycerides are the main storage form of fat in your body, transported through blood after meals. Elevated fasting triglycerides often signal insulin resistance, fatty liver, or excessive carbohydrate intake—often years before diabetes is diagnosed.
Triglycerides are fats composed of three fatty acid chains attached to a glycerol backbone. Blood triglycerides measure the total amount of this fat being transported, primarily in VLDL particles from the liver and chylomicrons from dietary fat absorption.
Why it matters.
The triglyceride-to-HDL ratio is one of the best surrogate markers for insulin resistance. High triglycerides drive production of small, dense LDL particles (more atherogenic), contribute to fatty liver, and independently predict cardiovascular disease and pancreatitis at very high levels.
Physiology.
After eating, dietary fats are packaged into chylomicrons and enter your bloodstream. Meanwhile, your liver produces VLDL particles carrying triglycerides to tissues for energy or storage. Insulin regulates this process—when cells become insulin resistant, the liver overproduces VLDL, and fat tissue fails to efficiently clear triglycerides, leading to elevated levels.
Testing & preparation.
How to prepare
- Fast for 9-12 hours (triglycerides are significantly affected by recent meals)
- Avoid alcohol for 24-48 hours before testing
- Avoid heavy exercise the day before testing
- Take the test in the morning for most consistent results
When to test
Part of standard lipid panel. Should be checked whenever assessing metabolic health, especially if overweight or with signs of insulin resistance.
How often
Every 1-2 years if optimal; every 3-6 months when making dietary changes or starting medications.
Interpretation.
High triglycerides
Common causes:
- Excessive carbohydrate intake, especially refined carbs and sugar
- Alcohol consumption (even moderate amounts)
- Obesity and visceral fat accumulation
- Insulin resistance and type 2 diabetes
- Hypothyroidism
- Genetic hypertriglyceridemia
- Certain medications (beta-blockers, corticosteroids, estrogen)
- Chronic kidney disease
Implications:
- Strong marker of insulin resistance
- Increased risk of fatty liver (NAFLD)
- Production of atherogenic small, dense LDL
- Very high levels (>500 mg/dL) risk pancreatitis
- May contribute more to cardiovascular risk in women
Low triglycerides
Common causes:
- Low-carbohydrate diet
- Malnutrition or malabsorption
- Hyperthyroidism
- Genetic factors
Implications:
- Generally favorable for metabolic health
- Extremely low levels (<35 mg/dL) may warrant investigation
- Often reflects good insulin sensitivity
Optimization.
Diet
- Reduce refined carbohydrates and added sugars dramatically
- Limit or eliminate sugary beverages (including fruit juice)
- Reduce or eliminate alcohol (largest single factor for many people)
- Increase omega-3 fatty acids from fatty fish (2-3 servings weekly)
- Choose complex carbohydrates with high fiber content
- Consider time-restricted eating (can significantly reduce triglycerides)
Lifestyle
- Weight loss (5% reduction can lower TG by 20-30%)
- Regular aerobic exercise (150+ min/week)
- Improve sleep quality and duration
- Reduce chronic stress (cortisol raises triglycerides)
- Quit smoking
Supplements
- Omega-3 fatty acids (EPA/DHA): 2-4g daily can lower TG 15-30%
- Prescription omega-3 (Vascepa): 4g EPA daily for very high TG
- Berberine: 500mg 2-3x daily
- Niacin: effective but side effects limit use
FAQs.
Why are my triglycerides high if I don't eat much fat?
Triglycerides are more influenced by carbohydrates than dietary fat. Your liver converts excess carbs (especially sugar and refined starches) into triglycerides. Alcohol is also a major driver. Focus on reducing refined carbs and alcohol rather than just fat.
How quickly do triglycerides respond to diet changes?
Triglycerides are among the fastest-responding lipid markers. You can see significant reductions (20-30%) within 2-3 weeks of cutting refined carbs and alcohol. This makes them an excellent feedback marker for dietary compliance.
What is the triglyceride/HDL ratio?
Divide your triglycerides by your HDL. A ratio below 2.0 is considered good; below 1.0 is optimal. High ratios (>3.0) strongly suggest insulin resistance, even when fasting glucose appears normal.
Do high triglycerides cause heart disease?
The relationship is complex. Very high triglycerides are independently associated with cardiovascular risk. More commonly, elevated triglycerides indicate the metabolic dysfunction (insulin resistance) that drives heart disease through multiple pathways including small dense LDL production.
Why test fasting triglycerides?
Triglycerides spike after meals (postprandial lipemia). Fasting values provide a consistent baseline reflecting your liver's triglyceride production. Non-fasting values can be 2-3x higher and harder to interpret.