Fatty liver disease is the accumulation of fat inside liver cells beyond a normal threshold, and since 2023 it has carried a new official name: metabolic dysfunction-associated steatotic liver disease, or MASLD. The most important thing to understand about it is that it is silent through most of its early course — and that the routine liver enzyme tests everyone knows (ALT and AST) can come back perfectly normal in people who already have inflammation and advanced scarring. A clean liver panel is not a clean bill of health.
This article explains what changed in the definition and why the change was not cosmetic, why liver enzymes alone are not enough, which simple score doctors now use first to rank risk (FIB-4) — calculated from tests you may already have — and then the number that matters most in the whole story: the percentage of body weight whose loss actually changes the disease, plus what physical activity can do even when the scale refuses to move.
One note before we start: this is educational content, not a diagnosis and not a treatment plan. Every number and test mentioned here is a question to bring to your doctor, not a decision to make on your own.
What is fatty liver disease, and why did its name change in 2023?
The liver works as a metabolic factory: it receives what arrives from the gut, stores, synthesises and distributes. When the fat being made and stored outpaces the fat being exported and burned, fat starts to accumulate inside liver cells. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) describes it as "a condition in which excess fat builds up in your liver," and distinguishes two forms: one where you "have fat in your liver but little or no inflammation or liver damage," and a more serious one where you "have inflammation of the liver and liver damage, in addition to fat in your liver" — the form once called NASH and now called MASH.
In June 2023, a multisociety Delphi consensus statement adopted by the American Association for the Study of Liver Diseases (AASLD) and its counterparts rewrote the vocabulary entirely. "Steatotic liver disease (SLD) was chosen as an overarching term to encompass the various aetiologies of steatosis." Under it, NAFLD became MASLD, NASH became MASH, and a new category — MetALD — was created for people who have MASLD and also drink alcohol at higher levels.
Why the rename was not cosmetic
Because the old name was a definition by negation. "Non-alcoholic fatty liver disease" literally meant: fat in the liver, not from alcohol, and not from anything else we know of. It was a diagnosis of exclusion — you arrived at it by ruling other things out. The new name is a definition by affirmation: ruling out other causes is no longer sufficient; at least one metabolic factor from a defined list must be present. AASLD explains the reasoning: "The vast majority of diseases currently designated as NAFLD are related to so-called 'metabolic' factors," and the initiative sought "an affirmative non-stigmatizing name and diagnosis" after patients noted that the word "fatty" can be stigmatising.
The five cardiometabolic criteria
To diagnose MASLD, liver fat must be present together with at least one of these five criteria, as published by AASLD:
- Body size: BMI ≥ 25 kg/m² (≥ 23 for Asian populations), or waist circumference above 94 cm in men and 80 cm in women.
- Blood glucose: fasting glucose ≥ 5.6 mmol/L (100 mg/dL), or HbA1c ≥ 5.7%, or established type 2 diabetes.
- Blood pressure: ≥ 130/85 mmHg, or being on antihypertensive treatment.
- Triglycerides: ≥ 1.70 mmol/L (150 mg/dL), or being on lipid-lowering treatment.
- HDL cholesterol: ≤ 1.0 mmol/L (40 mg/dL) in men, ≤ 1.3 mmol/L (50 mg/dL) in women.
Look closely at that list. Four of the five are numbers that already exist in a routine annual panel or on a home blood-pressure cuff. Which means a great many people meet the metabolic criterion without ever having connected it to their liver. (If you want the detail on waist circumference specifically, we devoted a whole article to visceral fat and why the scale doesn't show it — it's in our metabolic literacy series.)
Why aren't liver enzyme tests enough?
This is the point that gets missed more than any other. When a clinician suspects fatty liver, the usual first signal is a rise in the liver enzymes ALT and AST. But the relationship does not run in reverse: normal enzymes do not rule the disease out.
The AASLD Practice Guidance states it plainly: "Serum AST levels are often used clinically to identify patients with liver disease but can be normal in patients with diabetes, NASH, and advanced hepatic fibrosis." Read that last clause again: advanced hepatic fibrosis. The most consequential stage of the disease can coexist with a lab report that looks entirely reassuring.
And "normal" on the report is not always normal
There is a second layer to the problem. The same guidance notes that "a true normal alanine aminotransferase (ALT) ranges from 29 to 33 U/L in men and from 19 to 25 U/L in women" — figures lower than the reference range printed on many lab reports. The practical consequence is immediate: your result could read 38 U/L and carry no flag at all, because your lab treats "up to 40" as normal, while it actually sits above the true upper limit.
This is also why fatty liver is so often found by accident. Harvard Health puts it this way: "In its early stages, MASLD has no symptoms. It's often discovered by chance during an imaging test, such as abdominal ultrasound, MRI, or CT." Cleveland Clinic says almost the same thing: "Healthcare providers often find steatotic liver disease during routine tests for other conditions."
So what number actually measures the risk?
The good news is that clinicians are no longer forced to choose between "an enzyme panel that isn't enough" and "a liver biopsy." There is a middle step, and it has become the standard first move: the FIB-4 index.
FIB-4 is calculated from just four values, all of them usually already available: age, AST, ALT and platelet count. No special equipment, and in most cases no extra test. The AASLD Liver Fellow Network explains why it is preferred over biopsy: biopsies are "invasive, uncomfortable, and time consuming," carrying risks that range from "pain at the biopsy site to more life-threatening complications such as biliary leak, bleeding, and pneumothorax," while risk scores "typically only require the age of the patient and basic labs to calculate."
How the result is read
AASLD guidance sets out three zones:
- Below 1.3 — low risk: a "FIB-4 score less than or equal to 1.30 had a 90% negative predictive value," meaning it is very good at excluding advanced fibrosis; such patients can generally be managed in primary care.
- 1.3 to 2.67 — indeterminate: neither excludes nor confirms, and calls for secondary assessment.
- Above 2.67 — high risk: a "FIB-4 score greater than or equal to 2.67 had an 80% positive predictive value," warranting referral to specialty care.
When a result lands in the indeterminate zone, the next step is usually a measurement of liver stiffness — vibration-controlled transient elastography (FibroScan/VCTE) or the Enhanced Liver Fibrosis (ELF) blood test — which AASLD describes as "the preferred tools for secondary risk assessment." NIDDK notes that ordinary imaging — ultrasound, CT and MRI — can show fat accumulation but "can't show inflammation or fibrosis," which is precisely the gap elastography fills.
Here is the crux of it: the important question is not "do I have fat on my liver?" — that is extremely common — but "has the fat turned into inflammation and scarring?" The first is a description. The second determines the trajectory.
What actually reverses it? The dose is known and published
The landmark study here is Vilar-Gomez and colleagues, published in Gastroenterology in 2015: 293 patients with liver biopsy at baseline and again at 52 weeks of lifestyle modification. The headline numbers were modest. "25% of patients (72/293) obtained NASH resolution," "47% had improvement in nonalcoholic fatty liver disease activity score," and "19% had fibrosis regression."
But the breakdown is the real story
When results were sorted by how much weight each person actually lost, a steep gradient appeared:
- 10% or more of body weight lost: "90% of those with 10% or more weight lost achieving NASH resolution," and "100% of those who lost 10% or more achieved a two-point improvement in NAS score." For fibrosis, "45% regressing and 55% stabilizing."
- 7% to 10%: "64% of those in the 7% to 10% category" achieved NASH resolution, while "16% had fibrosis regression" and 84% stabilised.
- 5% to 7%: "62% of those in the 5% to 7% category" achieved improvement in the activity score.
The message is not a barked "lose 10%." It is something more precise and much fairer: the relationship is graded, and every percentage point buys something. Five per cent is not a failed attempt at ten; it is a gain in its own right. Harvard summarises the upper end of the gradient in one sentence: "Losing 10% of your body weight can reverse MASLD."
An important caveat: the speed of loss matters too. Very rapid loss and severely restrictive diets carry their own complications — we covered them in detail in our article on gallstones and the dieting mistake that creates them. The goal is gradual, sustainable, supervised loss, not a race.
The second lever: exercise works even without weight loss
This is one of the most liberating findings for anyone who has stalled on the scale. In a systematic review and meta-analysis led by Jonathan Stine, covering "14 studies with a total of 551 subjects who had NAFLD," the dose studied was equivalent to "150 minutes per week of brisk walking" (that is, ≥ 750 MET-minutes). The result: "39% of patients prescribed greater than or equal to 750 metabolic equivalents of task…achieved significant treatment response," against "only 26% of those prescribed lesser doses of exercise" — with response defined as a "greater than or equal to 30% relative reduction in MRI-measured liver fat."
And crucially: "Independent of weight loss, the team found exercise training was 3 1/2 times more likely to achieve clinically meaningful treatment response." You have two independent levers, not one. If you want the detail on what muscle itself does to your metabolism, we covered it in Muscle and Blood Sugar.
Why does sugar deserve its own section?
Because the liver does not merely store the fat you eat — it manufactures new fat from carbohydrate, in a process called de novo lipogenesis, and fructose is among its most efficient fuels.
In a randomised controlled trial published in the Journal of Clinical Investigation, 29 adolescent boys aged 11–16 with biopsy-proven fatty liver were assigned either to a diet restricting free sugars to under 3% of energy, or to their usual diet, for eight weeks. The reported result: "Hepatic DNL was significantly decreased in the treatment group (from 34.6% to 24.1%) versus the control group (33.9% to 34.6%) (adjusted week 8 mean difference: –10.6% [95% CI: –19.1%, –2.0%]), which was paralleled by greater decreases in hepatic fat (25.5% to 17.9% vs. 19.5% to 18.8%)."
Eight weeks. One intervention, aimed specifically at free sugars. This does not mean sugar is the sole cause of fatty liver — the picture is broader and includes weight, activity and insulin resistance — but it does mean sugar is an input that can be modified relatively quickly. Mayo Clinic lists the same advice under prevention: "Limit alcohol, simple sugars and portion sizes."
The bigger risk is not the liver — it's the heart
This is the paradox most people never hear. NIDDK notes that people with fatty liver face elevated risk of "cardiovascular disease, which is the most common cause of death" among them. Harvard says the same: "In people who have MASLD, cardiovascular disease is one of the most common causes of death," and offers the likely mechanism: "Experts believe that inflammatory compounds and other substances pumped out by a fat-afflicted liver may damage the insides of arteries, making plaque buildup more likely and setting the stage for a heart attack or stroke."
In other words, treating fatty liver is not a liver project alone; it is simultaneously a cardiac and metabolic project. Which is exactly why the five criteria above are not administrative detail — they are the risk map.
On the liver side, Cleveland Clinic lists the progression as hepatitis, then fibrosis, then cirrhosis, then liver failure — and adds the sentence worth memorising: "Early-stage steatotic liver disease can sometimes improve within months." The window is real. But a window is, by definition, a thing with a frame around it.
Fatty liver in Saudi Arabia: what the numbers say
A systematic review and meta-analysis published in Cureus in 2023 pooled eight studies with 4,045 participants: "The pooled prevalence of NAFLD among all adult populations in KSA was 16.8% (11.1%–22.5%)." Among people with type 2 diabetes, however, "the prevalence was 58.0% (45.0%–70.9%)." The authors themselves add a caution worth repeating: "there were no true general population studies of the prevalence of NAFLD in KSA available," so the first figure should be read as an estimate rather than a census.
A later Cureus meta-analysis in 2024 focused specifically on people with diabetes in Saudi Arabia and found pooled estimates "ranging from 47.8% to 72.8%," with substantial statistical heterogeneity (I² = 90.6%) and every included study relying on ultrasound — a method whose sensitivity is limited. The number, then, is a direction rather than a precise measurement. But the direction is unmistakable: where type 2 diabetes is present, fatty liver is the rule, not the exception.
Regionally, Global Burden of Disease 2021 data show that MASLD cases in the North Africa and Middle East region "increased from 35.92 million (1990) to 106.41 million (2021)," with the regional prevalence rate climbing from 22,409 to 31,829 per 100,000 population — among the highest anywhere in the world.
A practical seven-step plan
- Ask for the four numbers. At your next routine blood draw, make sure the report includes ALT, AST and platelet count — then ask your doctor directly: "Can you calculate my FIB-4?"
- Don't treat "normal" as the end of the conversation. If you have diabetes, prediabetes, raised blood pressure, raised triglycerides or increased waist circumference, ask about your liver even when the enzymes are in range.
- Aim for gradual, realistic weight loss. Five per cent is a genuine win, 7–10% more so, and 10% is where the highest response rates appear — gradually and with supervision, not through severe deprivation.
- Move for at least 150 minutes a week. Even if the scale doesn't budge. Brisk walking is a sufficient starting point.
- Cut sweetened drinks first. If there is one change worth starting today, it is liquid free sugars, because they feed hepatic fat synthesis most directly.
- Treat what surrounds the liver. Managing blood glucose, blood pressure and lipids is not a separate project; it is part of treating the liver itself.
- Skip the "liver cleanses." There is no reliable evidence behind herbal products and supplements marketed to detoxify the liver, and some carry a risk of liver injury themselves. Talk to your doctor before any supplement.
What about medication? And when should you see a doctor?
In March 2024, the U.S. Food and Drug Administration approved Rezdiffra (resmetirom) for adults with noncirrhotic NASH with moderate to advanced liver scarring, "to be used along with diet and exercise," noting that "previously, patients with NASH who also have notable liver scarring did not have a medication that could directly address their liver damage." That matters for two opposite reasons: the science is moving, and the drug is aimed at a narrowly defined group, is prescription-only, and is explicitly paired with diet and exercise rather than replacing them. Never request or discontinue a medication on the strength of an article.
See a doctor if any of the following appear, particularly alongside metabolic risk factors:
- Persistent pain or discomfort in the upper right abdomen.
- Severe, unexplained fatigue.
- Yellowing of the skin or the whites of the eyes (jaundice).
- Abdominal swelling or swelling in the legs.
- Repeatedly elevated liver enzymes across more than one test.
- A diagnosis of type 2 diabetes — on its own a sufficient reason to raise the liver question.
Those who should pay closer attention: people with type 2 diabetes or prediabetes, people with insulin resistance, and those with polycystic ovary syndrome, obstructive sleep apnoea or hypothyroidism — all of which appear on Mayo Clinic's risk-factor list. Pregnant and breastfeeding women and people with other liver conditions should not make radical dietary changes without medical supervision.
Where does Bakery 8 fit into this?
No bread treats fatty liver. We say it plainly before anything else: treating MASLD is an integrated metabolic project — weight, movement, glucose, blood pressure, lipids and medical follow-up. No single food product does that job, and ours don't either.
What a food choice can do is far narrower, and far more honest: it can remove one input among the inputs that feed hepatic fat synthesis — added sugar and refined carbohydrate load. That is precisely what the products of Bakery 8 / مخبز ثمانية in Riyadh, Saudi Arabia are built around: sugar-free, gluten-free, almond-flour formulations.
- Samoli and cloud bread — a daily alternative that keeps the shape of the meal you're used to, without the added sugar.
- Keto granola — for anyone who wants a fast breakfast instead of sweetened cereal.
- Sugar-free desserts — because occasions won't stop, and sustainability means having an alternative rather than total deprivation.
And honesty requires saying it: swapping one product for another is not a treatment plan. It is one step that makes the harder steps — gradual loss, regular movement, consistent follow-up — a little easier to sustain over the long run. That is the whole of our claim.
Frequently asked questions
Is fatty liver disease dangerous?
It depends on the stage. Fat alone without inflammation is the milder form, but once inflammation and fibrosis are added, the trajectory shifts toward cirrhosis and liver cancer. More importantly, the most common cause of death among people with MASLD is not the liver but cardiovascular disease, according to NIDDK. Early assessment of fibrosis stage is what defines the real risk.
Can fatty liver be completely reversed?
In its early stages, it can improve substantially. Cleveland Clinic notes that early-stage steatotic liver disease "can sometimes improve within months," and Harvard reports that losing 10% of body weight can reverse MASLD. With advanced fibrosis the goal shifts toward halting progression rather than full recovery — which is exactly why timing matters.
My liver tests are normal. Does that mean I'm fine?
Not necessarily. AASLD guidance states that AST "can be normal in patients with diabetes, NASH, and advanced hepatic fibrosis," and the true upper limit for ALT is lower than the range printed on many lab reports. If you carry metabolic risk factors, ask your doctor about a FIB-4 score rather than relying on the enzymes alone.
Does eating fatty food cause fatty liver?
The picture is wider than dietary fat. The liver manufactures new fat from carbohydrate, and free sugars feed that process directly; in a randomised trial in adolescents, hepatic de novo lipogenesis fell from 34.6% to 24.1% over eight weeks of free-sugar restriction. Body weight, insulin resistance and inactivity are equally central contributors.
Is exercise useful if my weight doesn't change?
Yes. In a meta-analysis of fourteen studies covering 551 people, 39% of those doing the equivalent of 150 minutes a week of brisk walking achieved at least a 30% reduction in liver fat, versus 26% at lower doses — and this was "independent of weight loss." Movement is an independent lever, not merely a means of losing weight.
The bottom line
Fatty liver disease is neither a rare diagnosis nor a loud one; it is common and quiet, and its new name reflects what it truly is — a metabolic disease before it is a liver disease. Enzyme tests alone cannot reassure you, a FIB-4 score is a simple thing worth raising at your next appointment, and the therapeutic dose is known and published: weight that comes down gradually, movement that works even when the scale doesn't, and added sugar that withdraws from the plate and from the day.
And if one of those choices means finding a sugar-free alternative that keeps you on the plan instead of abandoning it after two weeks, that is exactly what we make at Bakery 8. Healthy and delicious.
This article is for educational purposes only and is not a substitute for medical advice. Do not start or stop any medication or diet on the basis of it.
References
- American Association for the Study of Liver Diseases (AASLD). New MASLD Nomenclature — multisociety Delphi consensus, 2023.
- Rinella ME, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Hepatology, 2023.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Definition & Facts of NAFLD & NASH. NIH.
- NIDDK. Diagnosis of NAFLD & NASH. NIH.
- Rinella ME, et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology, 2023.
- AASLD Liver Fellow Network. Why are non-invasive risk scores such as FIB-4 used in clinical practice?
- AASLD Liver Fellow Network. Spare Me the Jab: Noninvasive Assessment of Patients with MASLD.
- Vilar-Gomez E, et al. Weight Loss Through Lifestyle Modification Significantly Reduces Features of Nonalcoholic Steatohepatitis. Gastroenterology, 2015;149(2):367–378.
- Cohen CC, Schwarz JM, et al. Dietary sugar restriction reduces hepatic de novo lipogenesis in adolescent boys with fatty liver disease. Journal of Clinical Investigation, 2021.
- Stine JG, et al. Exercise Training Is Associated With Treatment Response in Liver Fat Content by MRI Independent of Clinically Significant Body Weight Loss in Patients With NAFLD: A Systematic Review and Meta-Analysis. 2023.
- Mayo Clinic. Metabolic dysfunction-associated steatotic liver disease (MASLD).
- Cleveland Clinic. Steatotic (Fatty) Liver Disease.
- Harvard Health Publishing. An often-silent liver condition that threatens the heart.
- U.S. Food and Drug Administration. FDA Approves First Treatment for Patients with Liver Scarring Due to Fatty Liver Disease. 14 March 2024.
- Alhabeeb H, et al. Prevalence of Non-alcoholic Fatty Liver Disease (NAFLD) in Saudi Arabia: Systematic Review and Meta-analysis. Cureus, 2023;15(6):e40308.
- Prevalence of NAFLD Among Diabetes Mellitus Patients in Saudi Arabia: Systematic Review and Meta-Analysis. Cureus, 2024.
- Global, regional and national burden of MASLD in adolescents and adults aged 15–49 years from 1990 to 2021 (GBD 2021). Frontiers in Medicine, 2025.
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