Fatty Liver Index (FLI) Calculator
Screen for non-alcoholic fatty liver disease using a validated algorithm. Combines BMI, waist, triglycerides, and GGT into a 0-100 score.
The Fatty Liver Index (FLI) is a validated algorithm that predicts hepatic steatosis (fatty liver) without requiring ultrasound or liver biopsy. Developed by Bedogni et al. in 2006, it uses four routinely available measurements: triglycerides, GGT, waist circumference, and BMI.
FLI <30 effectively rules OUT fatty liver (negative likelihood ratio 0.2), while FLI β₯60 rules IN fatty liver (positive likelihood ratio 4.3). This makes it useful for population screening and tracking metabolic health over time.
- β’Extremely common: NAFLD affects 25-30% of adults worldwide, making it the most common liver condition globally.
- β’Silent progression: Fatty liver is usually asymptomatic until advanced stages. Early detection enables intervention before irreversible damage.
- β’Reversible with lifestyle: Unlike cirrhosis, early fatty liver can be reversed through diet, exercise, and weight management.
- β’Metabolic warning sign: NAFLD is strongly associated with insulin resistance, type 2 diabetes, and cardiovascular disease. It's often the hepatic manifestation of metabolic syndrome.
FLI screening is particularly valuable for:
- β’Anyone with elevated triglycerides (>150 mg/dL)
- β’People with elevated GGT (even mildly)
- β’Those with central obesity (increased waist circumference)
- β’Anyone with type 2 diabetes or prediabetes
- β’People with metabolic syndrome
- β’Those with family history of liver disease
- β’Anyone following a weight loss program (to track progress)
Since FLI combines metabolic markers, improving it requires addressing root causes:
- β’Reduce carbohydrates: Fructose and excess carbohydrates drive de novo lipogenesis (liver fat production). Reducing sugar and refined carbs often dramatically improves FLI.
- β’Lose visceral fat: Central adiposity directly correlates with liver fat. Weight loss of even 5-10% body weight can significantly reduce fatty liver.
- β’Eliminate alcohol: While FLI predicts NAFLD, any alcohol consumption stresses the liver. Abstinence accelerates fatty liver reversal.
- β’Exercise regularly: Both aerobic and resistance exercise reduce liver fat independently of weight loss. Aim for 150+ minutes per week.
- β’Consider coffee: Studies show coffee consumption is associated with lower GGT and reduced liver disease progression.
Track Your FLI Over Time
Monitor your fatty liver risk as you make lifestyle changes. Sign up free to save your results and see trends.
Start Tracking Free βUnderstanding Your FLI Result
FLI is a probability score from 0-100. Here are three perspectives on interpretation:
Standard Medical
Original Bedogni thresholds. Focus on ruling in/out hepatic steatosis.
| Range | Category | What It Means |
|---|---|---|
| < 30 | Rules Out Fatty Liver | Low probability of hepatic steatosis. 87% sensitivity for ruling out. |
| 30-59 | Indeterminate | Cannot rule in or out. Consider ultrasound if clinically indicated. |
| β₯ 60 | Rules In Fatty Liver | High probability of steatosis. 86% specificity. Discuss with provider. |
Research Consensus
Preventive approach based on large-scale epidemiological studies.
| Range | Category | What It Means |
|---|---|---|
| < 20 | Excellent | Minimal liver fat risk. Optimal metabolic health marker. |
| 20-29 | Good | Low risk. Still within safe zone but room for optimization. |
| 30-44 | Monitor | Early metabolic dysfunction possible. Active lifestyle intervention advised. |
| β₯ 45 | Elevated Risk | Significant metabolic burden. Comprehensive intervention recommended. |
Metabolic Optimization
Context for carbohydrate restriction, where rapid FLI improvements are common.
| Range | Category | What It Means |
|---|---|---|
| FLI drops >20 pts | Excellent response | Typical with carb restriction. Liver de novo lipogenesis decreasing. |
| FLI stable/improving | Good adaptation | Expected metabolic improvement with low-carb approach. |
| FLI unchanged | Investigate | Check adherence, alcohol intake, or other factors. |
| FLI increasing | Reassess diet | Unusual pattern. Review fat sources and overall intake. |
Frequently Asked Questions
Frequently Asked Questions
- Bedogni G, Bellentani S, Miglioli L, et al.. The Fatty Liver Index: a simple and accurate predictor of hepatic steatosis in the general population. BMC Gastroenterology, 6:33. 2006. PMID: 17081293
- Zelber-Sagi S, Webb M, Ber N, et al.. High red and processed meat consumption is associated with non-alcoholic fatty liver disease and insulin resistance. Journal of Hepatology, 68(6), 1239-1246. 2018. PMID: 29567099
- Gastaldelli A, Kozakova M, HΓΈjlund K, et al.. Fatty liver is associated with insulin resistance, risk of coronary heart disease, and early atherosclerosis in a large European population. Hepatology, 49(5), 1537-1544. 2009. PMID: 19291789
Medical Disclaimer
The Fatty Liver Index (FLI) calculator provided on Metabolicum is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Last updated: December 2025