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“Only my belly is sticking out.” “I was told I have metabolic syndrome at my checkup.” “My weight is normal, but my waist is huge.” Have you experienced any of these?
These may be signs of excessive visceral fat accumulation. Visceral fat is not just a cosmetic issue. Left untreated, it is a major risk factor for serious conditions such as type 2 diabetes, hypertension, myocardial infarction, and erectile dysfunction (ED).
In this article, a medical doctor explains the difference between visceral and subcutaneous fat, how to identify “hidden obesity”, and effective ways to reduce visceral fat through diet, exercise, and medical weight-loss treatment.
Table of Contents
Body fat is broadly divided into two types: visceral fat and subcutaneous fat. Each accumulates in a different location and has very different health implications.
Key Point: Visceral fat is metabolically active, which means it is easy to lose but also easy to gain. Men accumulate visceral fat more readily than women, and it can build up rapidly if neglected. Conversely, with the right approach, results can be felt within a relatively short period.
If your weight is normal but your checkup flagged abnormalities, you may have hidden obesity (visceral obesity). Because BMI is calculated from weight and height alone, it cannot capture the ratio of fat to muscle or where fat is distributed.
The more of the following items that apply to you, the more likely it is that visceral fat is accumulating.
Note: The most reliable way to measure visceral fat precisely is an abdominal CT scan (a cross-sectional area of 100 cm-squared or more at the navel level is diagnostic of obesity). At our clinic, we can also provide a general assessment using abdominal ultrasound or body composition analysis.
Visceral fat accumulation is driven by multiple intertwined factors in daily life. Understanding the causes that are particularly relevant to men makes it possible to take more effective countermeasures.
Consuming large amounts of refined carbohydrates such as white rice, bread, noodles, and sweets causes blood glucose spikes, and the surplus energy is preferentially stored as visceral fat. Diets high in saturated fats, such as fried foods and fast food, also drive visceral fat gain.
Alcohol is high in calories (about 7 kcal/g) and also promotes fat synthesis in the liver while inhibiting fat burning. It also stimulates appetite, so calorie intake from snacks during drinking sessions tends to climb. Beer, sake, and sweet cocktails are particularly high in carbohydrates and require extra caution.
The spread of desk-based work and remote work has reduced everyday activity levels, leading to a chronic state in which calorie expenditure falls below calorie intake. With less muscle mass, basal metabolism is also lower, and even a small amount of overeating can quickly translate into visceral fat.
Lack of sleep raises ghrelin (the appetite-stimulating hormone) and lowers leptin (the appetite-suppressing hormone). Chronic stress also increases secretion of cortisol (the stress hormone), and research has shown that cortisol directly promotes visceral fat accumulation.
Testosterone, the male hormone, helps maintain muscle mass and supports fat burning. As testosterone declines after age 40, muscle mass drops and fat is more easily stored. Increased visceral fat in turn lowers testosterone further, creating a vicious cycle.
Metabolic syndrome is a state in which visceral fat accumulation triggers multiple coexisting metabolic abnormalities. In Japan, it is diagnosed using the following criteria (jointly established by eight medical societies including the Japanese Society of Internal Medicine).
In other words, a waist circumference of 85 cm or more is required, and if two or more of the lipid, blood-pressure, or blood-glucose categories also exceed thresholds, a diagnosis of “metabolic syndrome” is made.
Visceral fat is more than just an “energy storage depot.” It actively secretes harmful substances called inflammatory cytokines and adipokines, disrupting metabolism throughout the body.
Inflammatory substances secreted from visceral fat, such as TNF-alpha and interleukin-6, damage blood vessel walls and accelerate atherosclerosis. People with metabolic syndrome have an approximately 2 to 3 times higher risk of myocardial infarction (per Japan’s Ministry of Health, Labour and Welfare statistics).
Visceral fat causes “insulin resistance,” which interferes with insulin’s action and leads to chronically elevated blood glucose (type 2 diabetes). Studies show that reducing visceral fat by just 5 to 10% can improve insulin sensitivity.
As visceral fat increases, fat also accumulates in the liver, progressing to non-alcoholic fatty liver disease (NAFLD). If left untreated, it can advance through hepatitis to cirrhosis and liver cancer.
Visceral fat accumulation reduces penile blood flow through low testosterone, vascular endothelial dysfunction, and atherosclerosis, leading to ED. The prevalence of ED in obese men is reported to be 2 to 3 times higher than in men of normal weight, so reducing visceral fat is also directly tied to improving ED.
Visceral fat responds quickly to dietary changes and tends to decrease before subcutaneous fat. Rather than extreme calorie restriction, simply changing the quality and order of your meals can produce major results.
What to Do: If you “eat less but still don’t lose weight,” review the content and order of your meals rather than just portion size. Late-night carbohydrate intake is the most likely to be stored as visceral fat, so even halving your evening carbs can produce noticeable results.
For men concerned about visceral fat or metabolic syndrome
Consult a doctor online. Even GLP-1 medical weight-loss treatment can be prescribed entirely through your smartphone.
The most effective approach to reducing visceral fat is to combine aerobic exercise with strength training. Either alone is rarely enough; sustained practice of both produces synergistic effects.
Aerobic activities such as walking, jogging, swimming, and cycling burn fat directly as energy. Because visceral fat tends to be burned before subcutaneous fat, continuing these activities relatively quickly improves waist circumference.
As muscle mass increases, resting calorie expenditure (basal metabolism) rises and your body becomes a “fat-burning body” even outside of workouts. Even starting with bodyweight exercises like squats, push-ups, and sit-ups can be effective.
Note: If you “don’t have time,” HIIT (High-Intensity Interval Training) is an efficient option. Just 8 sets of 20 seconds of all-out effort with 10-second rests (about 4 minutes total) is reported to produce a fat-burning effect comparable to roughly 30 minutes of steady-state aerobic exercise.
If diet and exercise alone are not producing results, or if you want faster outcomes, medical weight-loss treatment is another option. Combined with lifestyle improvements, it can efficiently reduce visceral fat.
These drugs enhance the action of GLP-1, a hormone secreted by the gut after meals. By acting on the brain’s appetite center to suppress hunger and stabilize blood glucose, they reduce body weight and visceral fat. Options include weekly self-injections (semaglutide) and daily oral tablets (Rybelsus). Clinical studies have also shown a tendency for visceral fat to decrease before subcutaneous fat.
Bofutsushosan is a Kampo (traditional Japanese herbal) medicine approved in Japan for “improvement of visceral (abdominal) obesity.” It supports fat burning and improves bowel movements, helping curb visceral fat accumulation. With relatively few side effects, it is suitable for long-term use.
STEP 1
Assessment (Waist Circumference, Blood Test, Interview)
Waist circumference, weight, and blood test results (triglycerides, HDL, blood glucose) are reviewed via online consultation to assess the degree of visceral fat and treatment eligibility.
STEP 2
Treatment Plan (Medication + Lifestyle)
The doctor selects the most suitable medication, such as GLP-1 injections, oral medication, or Kampo, and advises you on key dietary and exercise improvements.
STEP 3
Start Treatment at Home (Medication Delivered)
The prescribed medication is delivered to your home. Treatment begins with weekly injections or daily oral medication, alongside parallel improvements to diet and exercise.
STEP 4
Monthly Follow-Up and Effectiveness Review
Changes in weight and waist circumference are checked online every month. Side effects are monitored and dosage is adjusted as we provide ongoing support until your goals are reached.
This article has covered the characteristics of visceral fat and how to reduce it. Here are the most important points.
Start today, with just your smartphone.
Visceral fat & metabolic syndrome care | GLP-1 medical weight-loss | Online consultation available
Medication is delivered to your home, making it easy to keep going even with a busy schedule.
Reviewed by: Shimbashi Ginza Swift Clinic Physician
References: Japan Society for the Study of Obesity (JASSO) / Ministry of Health, Labour and Welfare / Japanese Circulation Society
AGA
