Visceral fat is the fat stored inside the abdominal cavity, around the liver, pancreas and intestines. It behaves like an active organ rather than passive storage, and it is associated with heart disease, type 2 diabetes and fatty liver disease in ways that the fat under your skin is not. [1]

The problem is that you cannot see it. A man can carry a clinically significant amount without looking overweight, and that gap between appearance and risk is what makes it worth understanding.

In this article

  1. What is visceral fat, and how is it different?
  2. Why men are more exposed
  3. The health risks linked to visceral fat
  4. The lean but metabolically unwell problem
  5. How to get a clearer picture of your risk
  6. What actually reduces visceral fat
  7. When to speak to a GP
  8. Frequently asked questions

What is visceral fat, and how is it different?

Your body stores fat in two main places. Subcutaneous fat sits just under the skin: you can pinch it, and it is the fat you see on the arms, thighs and around the waist. Visceral fat sits inside the abdominal wall, packed around the organs.

Location is what matters. Visceral fat drains into the portal vein, the blood vessel that feeds the liver directly, so the fatty acids and inflammatory signals it releases reach the liver first and in concentrated form. The exact share of the damage done by that direct route, versus by inflammation and by fat accumulating inside the liver itself, is still debated in the research, but the association between visceral fat and metabolic harm is consistent across studies. [1] [2]

Why men are more exposed

Men store proportionally more fat viscerally than women do. In imaging studies that measure the fat depots directly, men had more visceral fat than women at the same BMI and the same total body fat. [3] At the same age and BMI, men also showed a more adverse pattern of blood fats and blood sugar.

So two men can weigh the same, share a BMI and look broadly alike while carrying very different amounts of visceral fat. The one with more of it carries more metabolic risk, even if neither would call himself overweight.

The health risks linked to visceral fat

Cardiovascular disease

Visceral fat is associated with cardiovascular risk through several overlapping routes: inflammation, arterial stiffness, raised blood pressure and insulin resistance. Its signature on a blood test is not usually high LDL cholesterol. It is raised triglycerides, low HDL and a shift towards smaller, denser LDL particles, with LDL cholesterol itself often near normal. [4]

The American Heart Association's 2021 scientific statement on obesity concluded that abdominal obesity, measured by waist circumference, is a cardiovascular risk marker independent of BMI, and that studies measuring fat depots directly support visceral fat as an independent indicator of poor cardiovascular outcomes. [5] In plain terms: a large waist can flag raised cardiac risk in men whose weight and BMI would not.

Type 2 diabetes

Visceral fat is closely tied to insulin resistance. When the liver is exposed to a steady supply of fatty acids and inflammatory signals it responds less well to insulin, the pancreas compensates by making more, and over time that compensation can fail. Blood sugar rises, and type 2 diabetes follows. Men are diagnosed at a lower BMI than women, which fits the pattern above. [6]

The process can be well under way before a diagnosis. HbA1c, your average blood sugar over roughly the past three months, is one way to see where you are on that path, and it is the blood sugar marker in HeMed's panel.

Fatty liver disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously called non-alcoholic fatty liver disease, is fat building up inside liver cells. Liver UK (formerly the British Liver Trust) estimates it affects about 1 in 4 adults in the UK. [7] Visceral fat and insulin resistance are its main drivers, and it progresses silently; most people have no symptoms until the liver is already under strain.

Liver enzymes (ALT, AST and GGT) in the blood are one of the few early signals, with one caveat: normal liver enzymes do not rule MASLD out, because NICE notes that more than 80% of people with the condition have normal routine liver blood tests. [8] See Silent liver disease (MASLD): what to know.

Metabolic syndrome

Visceral fat sits at the centre of metabolic syndrome: a large waist, raised blood pressure, high triglycerides, low HDL and raised blood sugar. Three or more of the five is the standard definition, and the cluster is associated with roughly 2.3 times the risk of cardiovascular disease. [9] [10] Visceral fat is both a cause and a consequence of the cluster, which is why reducing it tends to move several markers at once. See Metabolic syndrome in men: symptoms, causes and what to do about it.

The lean but metabolically unwell problem

Visceral fat does not always come with visible obesity. A man can have a BMI in the healthy range, no obvious belly, and still carry enough visceral fat to raise his risk of heart disease, type 2 diabetes and liver disease. Researchers have called this metabolically obese normal weight, and estimates of how many normal-weight adults it describes range from about 2% to more than half, depending on the definition and population studied. [11]

This is why BMI alone is a poor screen for metabolic risk in men. Waist measurement is more informative:

  • The World Health Organization classes a waist above 94 cm in men as increased risk and above 102 cm as substantially increased risk. [12]
  • The International Diabetes Federation sets the central obesity cut point at 94 cm for men of European origin and 90 cm for men of South Asian, Chinese and Japanese origin. [9]
  • NICE, in its 2025 obesity guideline, recommends keeping your waist to less than half your height. A ratio of 0.5 to 0.59 means increased central adiposity and 0.6 or more means high. This check works across ethnicities and for men with high muscle mass, for whom BMI misleads, and applies at a BMI under 35. [13]

How to get a clearer picture of your risk

Waist circumference

Measure at the midpoint between your lowest rib and the top of your hip bone, standing, after breathing out normally, with the tape snug but not tight. [12] Then divide by your height. It is not a perfect proxy for visceral fat, but it beats BMI.

Blood markers

Blood tests do not tell you how much visceral fat you have. They show what it is doing to the systems around it, which is often the more useful question. The markers clinicians look at include:

  • Blood sugar: HbA1c, or a fasting glucose test, which a GP can arrange
  • Blood fats: triglycerides and HDL in particular, since both move with visceral fat; LDL and total cholesterol for overall risk
  • Liver enzymes: ALT, AST and GGT, remembering the caveat above
  • Thyroid function: TSH, because an underactive thyroid can cause a modest weight gain (much of it fluid) and tiredness that get mistaken for other things [14]
  • Inflammation: C-reactive protein (CRP), which some clinicians request to gauge the low-grade inflammation visceral fat produces

HeMed's at-home blood test covers 10 of these: total cholesterol, LDL, HDL, triglycerides, the cholesterol ratio, ALT, AST, GGT, HbA1c and TSH, with a clinician reviewing every result. It does not include CRP, and fasting tests are arranged through your GP. Read the marker definitions on What we test.

Clinical assessment

If you are concerned about visceral fat, the right starting point is a clinician reading your results in context rather than self-diagnosis from a tape measure. A clinician can see which risk factors are present, how they interact and what to do next.

What actually reduces visceral fat

Visceral fat responds to change, and in the early stages of weight loss it tends to go first: a review of 61 studies found modest weight loss removed visceral fat preferentially, though the advantage faded as losses grew larger. [15] The evidence for each lever:

  • A sustained energy deficit. Whatever the method, visceral fat falls when intake stays below expenditure over months, and it falls faster than total weight does early on. [15]
  • Aerobic exercise. The exercise type most consistently shown to reduce visceral fat in trials. Resistance training alone has not shown a significant effect on visceral fat in trials, though it protects muscle, so it belongs alongside aerobic work rather than instead of it. [16]
  • Sleep. In a controlled inpatient trial, two weeks of 4-hour nights increased visceral fat by 11% in healthy adults, driven mainly by eating around 300 more calories a day, and the extra visceral fat did not reverse during the recovery sleep that followed. [17]
  • Fewer sugary drinks and less alcohol. Fructose-sweetened drinks increased visceral fat over 10 weeks even when weight gain matched a glucose-sweetened comparison. [18] In a Japanese cohort of men, heavier drinking was associated with more visceral fat independent of BMI. [19]
  • Clinical support. Where visceral fat is contributing to significant metabolic risk, clinician-led weight management adds measurement and review to the levers above. Whether that is right for you is a clinical decision.

The point is not appearance. It is the load on your liver, heart and blood sugar regulation.

When to speak to a GP

Speak to your GP if your waist is 94 cm or more (90 cm for South Asian, Chinese or Japanese heritage), if your waist is more than half your height, if you have two or more components of metabolic syndrome, or if you have not had your blood pressure and blood fats checked in the last few years. In England the free NHS Health Check covers waist, blood pressure and cholesterol for adults aged 40 to 74. [20] The conditions visceral fat drives develop silently, and catching them early leaves you with more options.

Frequently asked questions

What is visceral fat and where does it sit in the body?

Visceral fat is stored inside the abdominal cavity around the liver, pancreas and intestines. Unlike subcutaneous fat, which sits under the skin, it is metabolically active and releases fatty acids and inflammatory compounds into the blood supply that feeds the liver.

Why is visceral fat more dangerous than subcutaneous fat?

Because of where it drains and what it releases. Its fatty acids and inflammatory signals reach the liver directly, and it is associated with insulin resistance, raised triglycerides, low HDL and fatty liver disease more strongly than fat under the skin is.

Can you have too much visceral fat without looking overweight?

Yes. Men can carry clinically significant visceral fat with a normal BMI and no obvious belly. Researchers call this metabolically obese normal weight. Waist-to-height ratio and blood markers tell you more than body weight alone.

What waist size indicates raised visceral fat risk in men?

The World Health Organization classes a waist above 94 cm as increased risk and above 102 cm as substantially increased. The cut point is 90 cm for men of South Asian, Chinese or Japanese origin. NICE adds a simpler rule: keep your waist under half your height.

Which blood markers are most relevant to visceral fat?

Triglycerides and HDL cholesterol, because both move with visceral fat; HbA1c or fasting glucose for blood sugar; and the liver enzymes ALT, AST and GGT for early liver strain. Some clinicians add CRP for inflammation. Together they show what the fat is doing, not how much there is.

Does visceral fat respond to diet and exercise?

Yes. A sustained energy deficit, aerobic exercise, enough sleep and less alcohol and sugary drink all reduce it, and modest weight loss removes visceral fat preferentially before the advantage fades with larger losses.

What should I do if I am concerned about visceral fat?

Measure your waist and compare it with half your height, then get your blood pressure, blood fats, blood sugar and liver enzymes checked and reviewed by a clinician. That gives you a picture of actual risk rather than a guess from the mirror.

HeMed provides clinician-led weight management. We do not diagnose or treat cardiovascular disease, type 2 diabetes or liver disease. This page is general health information, not medical advice. If you are worried about symptoms, speak to your GP, or use NHS 111.

Next step: see what the HeMed blood test measures.

Sources (20)
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Numbered markers in the page text link to these entries. Statistics describe populations, not any one person’s results.