Obesity kills slowly and indirectly, which is why it rarely appears on a death certificate and why it is so easy to postpone doing anything about. It does its work through the conditions it causes: heart attack, stroke, type 2 diabetes, obstructive sleep apnoea, fatty liver disease, several common cancers, osteoarthritis, and in men specifically, low testosterone and erectile dysfunction.

In Singapore the conversation is complicated by appearances. This is not a country where obesity is visually obvious in the way it is in parts of Europe or North America. Yet Singaporean adults carry a metabolic disease burden that is entirely out of proportion to how heavy they look, because in Asian populations the damage begins at a lower body weight and concentrates in a more dangerous place.

Why the standard BMI thresholds mislead in Asia

Body mass index is weight in kilograms divided by height in metres squared. The conventional cut-offs, overweight at 25 and obese at 30, were derived largely from European populations. Applied to Asian bodies they systematically underestimate risk.

At any given BMI, people of Chinese, Malay and Indian descent tend to carry a higher proportion of body fat and, critically, more of it in the abdominal cavity than people of European descent. The consequence is that metabolic complications appear earlier on the scale. Singapore's Health Promotion Board therefore uses lower action points, treating a BMI of 23 as the start of increased risk and 27.5 as high risk.

BMI (Asian cut-offs)	Category	Risk of metabolic disease
Below 18.5	Underweight	Risk of nutritional deficiency
18.5 to 22.9	Healthy range	Low
23.0 to 27.4	Moderate risk	Moderate, action recommended
27.5 and above	High risk	High, clinical management advised

Waist circumference is the better single measurement

BMI cannot distinguish muscle from fat, nor can it tell you where the fat sits. A more useful measure takes thirty seconds with a tape measure. Waist circumference above 90 centimetres in Asian men, or a waist-to-height ratio above 0.5, indicates excess visceral fat regardless of what the scale says.

This matters because "TOFI", thin outside fat inside, is a genuine and common phenotype in Singapore. A man with a BMI of 23, a normal-looking build and a waist of 92 centimetres can have a fatty liver, insulin resistance and an atherogenic lipid profile. He will pass a visual inspection and fail a blood test.

Why visceral fat is different

Subcutaneous fat, the layer under the skin, is largely inert storage. Visceral fat, packed around the liver, pancreas and intestines, behaves like an active endocrine organ, and not a helpful one.

Visceral adipose tissue secretes inflammatory cytokines that circulate throughout the body and promote insulin resistance. It releases free fatty acids directly into the portal vein, delivering them to the liver at high concentration and driving fatty liver disease and excess glucose production. It disrupts the hormones that regulate appetite, so leptin signalling becomes blunted and hunger persists despite abundant stored energy. And in men it converts testosterone to oestrogen through the aromatase enzyme, which lowers testosterone, which in turn makes it harder to build muscle and easier to accumulate more fat.

That last mechanism creates a self-reinforcing loop that is one of the reasons weight gain in men accelerates through the forties. Fat lowers testosterone, low testosterone increases fat mass and reduces the drive to train, and the cycle tightens.

What excess weight actually does to a man's body

Cardiovascular and metabolic

Obesity is a primary driver of hypertension, dyslipidaemia and type 2 diabetes, the three conditions responsible for most premature cardiovascular death in Singapore. Excess weight raises blood pressure through increased blood volume, sympathetic nervous system activation and effects on kidney sodium handling. It raises triglycerides and lowers HDL. It produces small dense LDL particles that penetrate artery walls more readily.

Sleep

Obstructive sleep apnoea is dramatically more common with central obesity, and is grossly underdiagnosed. Fat deposition around the upper airway and neck causes repeated collapse during sleep, with dozens or hundreds of oxygen desaturations per night. The consequences are not limited to snoring and daytime fatigue: untreated sleep apnoea independently raises blood pressure, worsens glucose control, increases arrhythmia risk and impairs testosterone production. Poor sleep then increases appetite and reduces training capacity, closing another loop.

Liver

Metabolic dysfunction-associated fatty liver disease is now among the most common liver conditions worldwide and is strongly linked to visceral fat and insulin resistance. Most cases are silent, picked up as a mildly raised ALT on a screening panel or as a bright liver on ultrasound. A minority progress to inflammation, fibrosis and cirrhosis. Weight loss remains the only reliably effective treatment.

Sexual and hormonal health

Erectile dysfunction is substantially more common in men with obesity, through three separate routes: endothelial dysfunction in the small penile arteries, lower testosterone from aromatase activity, and the psychological burden of body image and low energy. Because penile arteries are narrower than coronary arteries, erectile difficulty often appears years before cardiac symptoms and is a genuine early warning sign worth investigating rather than ignoring.

Cancer

Excess body fat is an established risk factor for cancers of the colon, oesophagus, pancreas, kidney and liver, among others. The mechanisms involve chronic inflammation, elevated insulin and insulin-like growth factor signalling, and altered sex hormone levels.

Why willpower is the wrong frame

The advice to eat less and move more is not wrong, it is just incomplete in a way that sets people up to fail. Body weight is defended physiologically. When you lose weight, resting metabolic rate falls by more than the loss of tissue alone accounts for, ghrelin rises, leptin falls, and the subjective experience of hunger increases and stays increased for a long time. This is a biological response, not a character flaw, and it explains why most unsupported diets are followed by regain.

The environment does not help. Singapore's food culture is one of the great pleasures of living here and also a landscape of high-calorie, high-sodium, highly available options served late into the night. Long working hours compress sleep and exercise. Air-conditioned convenience reduces incidental movement. None of this is an excuse, but a plan built without accounting for it is a plan that will not survive contact with a Tuesday.

What actually works

Protein, resistance training and sleep before anything else

The three interventions with the best ratio of benefit to difficulty are raising protein intake to roughly 1.6 grams per kilogram of body weight, resistance training at least twice weekly, and getting seven hours of sleep. Protein preserves lean mass during a deficit and is the most satiating macronutrient. Resistance training protects muscle, which protects resting metabolic rate and glucose disposal. Sleep restriction reliably increases appetite and reduces adherence to everything else.

A modest, sustainable deficit

A deficit of roughly five hundred calories a day produces around half a kilogram of loss per week, which is fast enough to be motivating and slow enough to preserve muscle. Aggressive crash dieting produces faster scale movement, more muscle loss, worse hunger and higher regain rates.

Five to ten percent is enough to change your labs

This is the most underrated fact in weight management. You do not need to reach an ideal weight to gain most of the health benefit. Losing five to ten percent of starting body weight produces clinically meaningful improvements in blood pressure, HbA1c, triglycerides, liver enzymes and sleep apnoea severity. For a hundred kilogram man, that is five to ten kilograms, not thirty.

Medication where it is appropriate

GLP-1 receptor agonists have changed what is achievable for people with significant obesity or obesity with metabolic complications, producing average losses well beyond what lifestyle intervention alone typically delivers. They are not a shortcut around the fundamentals, they work best alongside protein, training and sleep, and they require medical supervision, dose titration and an exit strategy. We cover them in detail in our guide to prescription medication for weight loss.

Measure the right things

Scale weight fluctuates daily with sodium, carbohydrate, hydration and bowel habit. Tracking a weekly average, waist circumference monthly, and blood markers every three to six months gives a far more honest picture of progress than a daily number that moves for reasons unrelated to fat.

Where to start

A useful first step is a baseline that tells you what the weight is actually doing to your body: fasting glucose and HbA1c, a lipid panel, liver function, thyroid function, testosterone, blood pressure and waist circumference. Those results turn an abstract goal into a specific target with a measurable review point at three months.

Frequently Asked Questions

Q: My BMI is 24, which is normal by international standards. Should I be concerned in Singapore?

A: Possibly. Singapore uses lower action points for Asian populations, treating 23 and above as moderate risk, because metabolic complications appear at lower body weights in Asian bodies. Check your waist as well: above 90 centimetres for a man, or a waist greater than half your height, indicates excess visceral fat even when BMI looks acceptable.

Q: How much weight do I need to lose to see health benefits?

A: Five to ten percent of your starting weight is enough to produce measurable improvements in blood pressure, HbA1c, triglycerides, liver enzymes and sleep apnoea. Most of the metabolic benefit arrives early in the process, which is why aiming for a realistic first target beats aiming for an ideal weight and abandoning the attempt.

Q: Why do I regain weight so easily after losing it?

A: Because your body actively defends its previous weight. After loss, resting metabolic rate falls more than tissue loss alone explains, the hunger hormone ghrelin rises and leptin falls, and appetite stays elevated for a long period. This is physiology, not weakness. It is also why maintenance needs a plan of its own rather than being treated as the absence of dieting.

Q: Can obesity cause low testosterone and erectile dysfunction?

A: Yes, through several routes at once. Visceral fat converts testosterone to oestrogen via aromatase, obesity impairs the function of blood vessel linings including the small arteries supplying the penis, and associated sleep apnoea further suppresses testosterone production. Weight loss frequently improves both testosterone levels and erectile function without any hormonal treatment.

Q: Is exercise or diet more important for weight loss?

A: Diet drives most of the weight loss, exercise drives most of the health improvement and most of the maintenance. Trying to out-train a calorie surplus rarely works because exercise burns fewer calories than people assume and can increase appetite. Trying to lose weight by diet alone without resistance training costs you muscle you will want to keep.

Q: Are weight loss medications safe to use long term?

A: The current generation of GLP-1 medications has an established safety profile in clinical use, with gastrointestinal side effects being the most common issue and generally manageable with slow dose escalation. They are prescription medicines that require assessment, monitoring and a plan for what happens when treatment stops, since weight regain is common on discontinuation without an established lifestyle foundation.

Book a weight management consultation at our Orchard clinic or speak to a doctor about a baseline metabolic assessment.

Obesity: The Silent Killer Behind Singapore's Chronic Disease Burden