The Lipid Accumulation Product, usually shortened to LAP, estimates how much fat sits inside your abdomen from two inputs only: your waist circumference and your fasting triglycerides. That makes it a half-home, half-lab measurement. The tape part takes a minute; the triglyceride part needs a blood draw after an overnight fast, so you cannot finish the score without a lipid panel. No scanner, no bioimpedance scale and no specialist visit are involved.
It was published in 2005 as a cheap alternative to body mass index, on the argument that where fat sits matters more than what a person weighs. It is a continuous score, not a yes-or-no test.
What you need
- A flexible, non-stretch tape measure.
- Your waist circumference in centimeters, measured on bare skin.
- Your fasting triglycerides, from a standard lipid panel drawn after roughly 9 to 12 hours without food. Triglycerides appear on every routine panel, so no extra test needs ordering.
- Your sex, because the score uses a different baseline waist value for men and for women.
Height, weight and age are not used. If your lab reports triglycerides in mg/dL rather than mmol/L, the value has to be converted first.
How the measurement works
Measure the waist standing, at the end of a normal breath out, with the tape midway between the lowest rib and the top of the hip bone. Keep it snug but not compressing, and level all the way around. Measure twice, and repeat if the two readings differ by more than a centimeter.
The score then takes the amount by which your waist exceeds a fixed baseline circumference for your sex, and multiplies it by your fasting triglyceride concentration. Both inputs push the same way, and because they multiply rather than add, someone high on both lands far above someone high on only one. If your waist is at or below that baseline, the score bottoms out near zero and stops discriminating. The baseline is lower for women than for men, so male and female values cannot be compared with each other. Rather than doing the arithmetic by hand, enter your two numbers into the Lipid Accumulation Product (LAP) and let it apply the sex-specific constant for you.
How to read the result
There is no single internationally agreed cut-off for LAP. Published studies either split their populations into quartiles or derive local thresholds by ROC analysis, and those thresholds differ substantially between countries and between the sexes. A value that flags risk in one cohort sits mid-range in another.
So read it as a direction of travel, not a verdict. A higher score means a greater likelihood that fat is accumulating around the organs rather than under the skin. The most useful comparison is with your own earlier value, measured the same way on the same lab’s assay. If you want a threshold-based reading instead, the tape-only Waist-to-height ratio (WtHR) has better-established reference points, and the Fatty Liver Index (FLI) adds liver enzymes to the same two inputs when fatty liver is the specific question.
What it does not tell you
LAP does not measure visceral fat; it correlates with it. Only cross-sectional imaging, CT or MRI, quantifies visceral fat area directly, with DEXA giving an approximation.
It also cannot separate fat around the organs from fat inside the liver, and it inherits every weakness of the triglyceride test. A late meal, alcohol the night before, acute illness, untreated thyroid disease, poorly controlled diabetes or pregnancy can all inflate triglycerides for reasons unrelated to abdominal fat. The reverse matters just as much: fibrates, high-dose omega-3 and, to a lesser extent, statins lower triglycerides directly, so treatment can drop the score while the waist is unchanged.
The index was derived in a general adult US population, and the relationship between waist size and visceral fat varies by ancestry, with South Asian and East Asian populations tending to carry more visceral fat at any given waist. It has not been established for children, adolescents or pregnancy. And it is a risk marker, not a diagnosis: it says nothing about your blood pressure, glucose, muscle mass or liver enzymes, and a reassuring value does not rule any of those out.
Related reading
Disclaimer. This article is for information only and does not replace medical advice. Talk to a qualified clinician before changing anything about your health.