【Obesity Is the Gateway to Disease】How Metabolic Syndrome and Diabetes Differ and Connect, the Chain of Illness That Starts with Belly Fat, and How to Break It

“I’ve put on a little weight, but I don’t have diabetes yet, so I’m fine.” Is that what you’re thinking?

Some of you may also be wondering, “What’s the difference between metabolic syndrome and diabetes?”

The truth is, obesity and metabolic syndrome are in themselves the gateway to serious illness.

The “chain of fear” of metabolic syndrome → diabetes → heart disease → dementia often progresses quietly, without any noticeable symptoms.

When I was at my heaviest (over 70 kg / 154 lb), my waist, blood pressure, and blood sugar all hit the criteria for metabolic syndrome.

I’ve experienced firsthand just how dangerous the feeling of “I’m fine for now” can be.

In this article, I’ll clearly explain the chain of illness that obesity and metabolic syndrome set off, and how to break that chain through fasting and lifestyle improvements.

Along the way, let’s also sort out the differences and the relationship between metabolic syndrome and diabetes, based on their diagnostic criteria.

What’s the Difference Between Metabolic Syndrome and Diabetes? Their Diagnostic Criteria

Metabolic syndrome and diabetes are both terms you often hear at health checkups, but they mean completely different things.

First, let’s lay out the definition and diagnostic criteria for each.

What Is Metabolic Syndrome?

Metabolic syndrome (visceral fat syndrome) refers to a state in which, in addition to a buildup of visceral fat, two or more of high blood sugar, high blood pressure, and abnormal blood lipids overlap.

Put simply, it’s a state where fat around the belly overlaps with abnormalities in blood sugar, blood pressure, and lipids.

Japan’s diagnostic criteria for metabolic syndrome are as follows.

Metabolic syndrome is diagnosed when waist circumference is 85 cm (33.5 in) or more for men and 90 cm (35.4 in) or more for women (visceral-fat-type obesity), and two or more of the following three items also apply.

According to data from Japan’s Ministry of Health, Labour and Welfare, about 30% of men and about 10% of women aged 40 and over meet the criteria for metabolic syndrome, and including those at risk, about half of all adults are said to fall into this group.

You can see that this is by no means a problem for only a small number of people.

What Is Diabetes?

Diabetes, on the other hand, is a disease in which the sugar in your blood (blood sugar) stays chronically high.

Blood test numbers are used for diagnosis, with guidelines such as a fasting blood sugar of 126 mg/dL or higher, or an HbA1c (a number that reflects your average blood sugar over the past 1 to 2 months) of 6.5% or higher.

If you meet the criteria, a procedure of retesting on a different day to confirm may also be followed.

Diabetes has almost no noticeable symptoms in its early stages, and as it progresses, signs such as feeling thirsty, urinating more often, and losing weight even though you’re eating may appear.

By the time symptoms show up, it has often already progressed, so it’s important to notice early through your health checkup numbers.

How the Two Differ and How They’re Connected

Metabolic syndrome is judged by the combination of “belly fat + abnormalities in blood sugar, blood pressure, and lipids,” whereas diabetes is judged by the test numbers for blood sugar and HbA1c.

To put it another way, the difference is like metabolic syndrome being “a highly flammable house where fires break out easily,” and diabetes being “a house that has already caught fire.”

In the research world as well, metabolic syndrome is sometimes positioned as a stage before diabetes.

In other words, if you take action at the metabolic syndrome stage, there’s a good chance you can prevent it from progressing to diabetes.

How Metabolic Syndrome Progresses to Diabetes: Visceral Fat and Insulin Resistance

What makes metabolic syndrome frightening isn’t that it’s a problem on its own, but that it’s “the gateway to the next illness.”

Metabolic abnormalities centered on visceral fat set off a chain of illnesses throughout the body, like falling dominoes.

Here, let’s look at the process from metabolic syndrome to diabetes, stage by stage.

Stage 1: Chronic Inflammation Caused by Visceral Fat

Visceral fat isn’t just a “lump of fat”; it functions as an “inflammation factory” that secretes inflammatory substances (cytokines) such as TNF-α and IL-6.

This causes chronic inflammation throughout the body and lays the groundwork for all kinds of illnesses.

Inflammation is like a small smoldering fire inside the body.

When visceral fat builds up, these small fires can keep smoldering throughout your body.

Because it progresses with almost no noticeable symptoms, it’s not uncommon for the embers to have already spread inside your body by the time you notice.

Stage 2: Insulin Resistance and Type 2 Diabetes

Inflammation from visceral fat interferes with insulin signaling, and insulin resistance worsens.

To put it simply, it’s a state where insulin stops working as well.

Insulin is a hormone that gets the sugar in your blood taken up into your cells; it’s like “the key that opens the door to your cells.”

It’s said that in about 80 to 90% of people with diabetes, obesity or metabolic syndrome came first.

Also note that people who meet the criteria for metabolic syndrome are said to have about 5 to 10 times the risk of developing diabetes compared with those who don’t.

Think of metabolic syndrome as something like “the trailer for diabetes.”

Watch Out for Blood Sugar Spikes After Meals, Too

Even if your fasting blood sugar is normal, some people experience “blood sugar spikes,” where blood sugar rises sharply only after meals.

Blood sugar spikes are hard to detect in regular health checkups, and they damage your blood vessels and burden your pancreas without you noticing.

If you often feel very sleepy or sluggish after eating, it’s a good idea to review how much you eat and the order you eat in.

The Illnesses That Lie Beyond Diabetes: Heart Disease, Stroke, Dementia, and Cancer

The chain of illness brought on by metabolic syndrome and obesity doesn’t stop at heart disease and diabetes.

Recent research has also strongly indicated links to dementia and cancer.

Stage 3: Arteriosclerosis, Heart Disease, and Stroke

When high blood sugar, high blood pressure, and abnormal lipids combine, damage to the blood vessel walls accelerates.

Your blood vessels lose their flexibility, just as an old hose becomes hard and brittle.

This is arteriosclerosis, and it’s said to be a major cause of heart disease and stroke, which are among the leading causes of death in Japan.

People with metabolic syndrome are said to have 3 to 4 times the risk of heart disease and 2 to 3 times the risk of stroke compared with healthy people.

The Link Between Obesity and Dementia

There is data showing that obesity in middle age (BMI of 30 or higher) raises the risk of Alzheimer’s disease later in life by up to 3 times.

The following pathways are thought to be the mechanisms.

Amyloid beta is a protein, like garbage in the brain, that’s considered one of the causes of Alzheimer’s disease.

The Link Between Obesity and Cancer

WHO research reports have also shown that obesity raises the risk of 13 or more types of cancer, including breast, colorectal, endometrial, pancreatic, and liver cancer.

Chronic inflammation and a state in which large amounts of insulin keep being released are thought to create an environment where cancer cells grow more easily.

Even if you think, “I’m just a little overweight,” a chain may be quietly progressing inside your body.

The idea that “being overweight is fine” is one of the most dangerous misconceptions.

Visceral fat acts like an “organ” that affects your health throughout your entire body.

Diabetes Complications Can’t Be Overlooked Either

As diabetes progresses, damage spreads to the eyes, kidneys, and nerves, which have many small blood vessels.

Retinopathy, in which the retina of the eye is damaged; nephropathy, in which kidney function declines; and neuropathy, which causes numbness in the hands and feet, are known as the typical complications of diabetes.

All of them greatly lower your quality of life, so it’s very important to stop things at the metabolic syndrome stage, before diabetes develops.

Is Visceral Fat More Dangerous Than Subcutaneous Fat? Getting to Know What Metabolic Syndrome Really Is

At the core of metabolic syndrome is “visceral fat.”

Even though both are fat, subcutaneous fat and visceral fat affect the body very differently.

The Difference Between Visceral Fat and Subcutaneous Fat

Subcutaneous fat is fat that sits just under the skin, and you can pinch it with your fingers.

Visceral fat, on the other hand, is fat that forms around internal organs such as the stomach and intestines, and you can’t pinch it from the outside.

If your belly sticks out but there isn’t much you can pinch with your hand, it may be a sign that you have a lot of visceral fat.

If you’re concerned, it’s a good idea to compare your waist measurement from your health checkup year by year.

You Can’t Let Your Guard Down Even If You Look Slim

Visceral fat is hard to see from the outside, so people with thin arms and legs but a belly that sticks out need to be careful.

Some people have “hidden metabolic syndrome,” where visceral fat has built up from lack of exercise or overeating even though their weight is normal.

It’s important to pay attention not just to your weight but also to the size of your waist.

How to Check Your Visceral Fat

At home, an easy method is to measure around your belly at the level of your belly button.

If it’s 85 cm (33.5 in) or more for men or 90 cm (35.4 in) or more for women, consider it a sign that visceral fat has built up.

With the results of your yearly health checkup too, comparing your blood sugar, blood pressure, triglycerides, and HDL cholesterol with last year’s makes it easier to notice changes in yourself.

Visceral fat is also said to be fat that “builds up easily but also comes off easily,” so if you notice early, you can take plenty of action against it.

Lifestyle Habits That Make Visceral Fat Build Up

Visceral fat tends to build up when the balance between how much you eat and how much you burn is thrown off.

In particular, when things like carb- and fat-heavy meals, constant grazing, late-night eating, lack of exercise, drinking too much alcohol, lack of sleep, and stress pile up, fat tends to accumulate around your belly.

Men tend to accumulate visceral fat easily, and women are also said to build up visceral fat more easily after menopause as female hormones decrease.

Losing muscle with age and the resulting drop in metabolism is also one of the causes of increased visceral fat.

Reduce Visceral Fat Through Fasting and Break the Chain of Illness

One of the most effective approaches to stopping the chain of illness that starts with metabolic syndrome and obesity is fasting (intermittent fasting).

Fasting works directly on visceral fat.

Visceral fat could be called the first domino in the chain of illness.

Why Fasting Burns Visceral Fat First

When insulin drops during fasting, the body uses fat rather than carbohydrates as its energy source.

Insulin is also “the one in charge of storing fat,” so when insulin goes down during your fasting hours, it becomes easier to draw on stored fat.

At this point, visceral fat has the property of being broken down and burned more easily than subcutaneous fat, so fasting efficiently reduces visceral fat.

Visceral fat is like “a checking account you can use right away,” and subcutaneous fat is like “a fixed-term deposit that’s hard to withdraw.”

This property is thought to be the reason your waist size is the first to change.

Effects Reported in Research

Multiple meta-analyses pooling clinical trials of intermittent fasting have consistently reported a reduction in visceral fat along with improvements in insulin sensitivity, blood pressure, and lipid profiles.

Insulin sensitivity refers to how well insulin works.

In other words, it can work on all of the diagnostic items for metabolic syndrome at the same time.

Being able to tackle blood sugar, blood pressure, triglycerides, and waist circumference all at once with a single habit is a big draw.

A selective effect on visceral fat in particular has been reported, and it’s considered one of the effective approaches to improving metabolic syndrome.

For me too, within three months of starting to fast, my waist shrank by 7 cm (2.8 in) and my triglycerides returned to normal.

When visceral fat goes down, your body doesn’t just feel lighter; even your mood and focus start to change!

If You’re Being Treated for Diabetes, Always Consult Your Doctor

However, people who have already been diagnosed with diabetes and are being treated with medication or insulin injections need to be careful.

Fasting on your own judgment can cause hypoglycemia, where your blood sugar drops too low.

If you’re under treatment, be sure to consult your doctor before starting to fast.

Points to Keep Fasting from Losing Its Effect

Practical Fasting Steps and a Lifestyle Checklist to Prevent Metabolic Syndrome and Diabetes

The key to sticking with fasting is to let your body get used to it little by little rather than suddenly attempting long fasts.

Here, I’ll introduce step-by-step fasting stages along with the lifestyle habits worth reviewing at the same time.

A Concrete Fasting Protocol

During your eating hours, eating vegetables and protein first and saving rice or bread for last helps keep your blood sugar from rising.

The reason to combine strength training with your exercise is that muscle becomes “a place to use sugar,” burning a lot of the sugar in your blood.

When you build muscle, insulin also tends to work better, bringing you closer to a body where visceral fat is less likely to build up.

Effective for Improving Metabolic Syndrome! A Lifestyle Checklist and Steps You Can Take Starting Today

Before you start fasting, first get a handle on the problem areas in your current lifestyle.

Check which items apply to you in the checklist below, and find the points you should prioritize improving.

If three or more apply to you, starting to improve your lifestyle right now is the first step toward fighting off visceral fat.

You don’t need to change everything at once.

Building up small habits like “no eating after 10 p.m.” and “cutting out snacks” eventually leads to big changes.

Pick one thing you can do starting today, such as switching sweet drinks to water or tea, or walking one extra train stop.

Having fewer items checked is also a sign that you’re getting closer to a lifestyle in which visceral fat comes off more easily.

Look over this list again in a month and see how you’ve changed.

Frequently Asked Questions About Metabolic Syndrome and Diabetes

Take Action While It’s Still Metabolic Syndrome, and the Chain of Illness Can Be Stopped

Metabolic syndrome and diabetes are different things, but metabolic syndrome can be called a stage that comes before diabetes.

That’s exactly why reducing visceral fat, the first domino in the chain, matters more than anything.

If you create fasting hours and review what you eat, your exercise, and your sleep, you can gradually reduce visceral fat.

Start by reviewing your health checkup results and measuring your waist to find out what stage you’re at right now.

Here’s a summary of the key points.

You need to know, starting today, the risks of leaving a “just a little overweight” condition alone.

Taking action right now is the best investment you can make to protect your health 10 and 20 years from now.

For a scientific program focused on improving visceral fat and metabolic syndrome, also take a look at ufeelgreat: a science-based fasting program to reset visceral fat and metabolic syndrome.

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