You step on the scale. The doctor glances at your height and weight, tells you your BMI is normal, and moves on. You leave feeling reassured, but three months later, your fasting blood sugar is elevated, your cholesterol is off, and your blood pressure has crept up.
This is not a rare story. It happens regularly, and it happens because BMI, body mass index, measures only one thing: weight relative to height. It says nothing about where that weight lives in your body, what it's made of, or how your metabolism is functioning.
For Filipino patients in particular, relying on BMI alone carries a specific and well-documented risk.
What BMI actually measures
BMI is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). It was developed in the 1830s by a Belgian mathematician, not a physician, as a statistical tool for population studies. It was never designed to diagnose individual health.
The standard international classification from the WHO looks like this:
| BMI Range | Classification (General/Western) |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
These cutoffs were established primarily from data on European and North American populations. The problem is that bodies are not all built the same way, and research has shown clearly that Asians, including Filipinos, develop metabolic complications at lower BMI values than their Western counterparts.
The Filipino-specific BMI problem
The WHO itself, in its 2004 expert consultation, recommended lower action thresholds for Asian populations. At equivalent BMI values, Asians tend to carry a higher proportion of body fat, particularly visceral fat, than people of European descent. This means the metabolic risk that kicks in at BMI 25 for a Caucasian person may already be present at BMI 22 or 23 in a Filipino.
The Asia-Pacific BMI cutoffs recommended for clinical use:
| BMI Range | Classification (Asia-Pacific / Filipino) |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 22.9 | Normal weight |
| 23.0 – 27.4 | Overweight, increased risk |
| 27.5 and above | Obese, high risk |
This is clinically significant. A Filipino patient with a BMI of 24, who would be told they are "normal" by the Western standard, is already in the overweight range by Asia-Pacific criteria and may warrant metabolic screening.
Visceral fat vs. subcutaneous fat: why it matters
Not all body fat is equivalent. There are two main types:
- Subcutaneous fat sits just under the skin. You can pinch it. It's the fat on your arms, thighs, and hips. It is metabolically relatively inactive at normal levels.
- Visceral fat surrounds your internal organs, liver, pancreas, intestines. It is metabolically active and inflammatory. It releases fatty acids and hormones that drive insulin resistance, high triglycerides, elevated blood pressure, and systemic inflammation.
BMI cannot tell visceral fat from subcutaneous fat. A person who is "thin" by the scale can carry significant visceral fat, this is sometimes called TOFI: thin outside, fat inside. This pattern is more common in Asians and is associated with the same cardiovascular and metabolic risks as obesity, even in people with normal BMI.
Conversely, a muscular person with a BMI of 27, technically "overweight", may have very little visceral fat and excellent metabolic health. BMI cannot distinguish between these two people.
Better measurements to ask your doctor about
None of these replace a full clinical assessment, but each gives information that BMI cannot:
Measures central (abdominal) fat directly. Better predictor of visceral fat than BMI.
Risk threshold (Filipino): >80 cm women / >90 cm menWaist divided by hip circumference. Reflects fat distribution pattern and cardiovascular risk.
Risk threshold: >0.85 women / >0.90 menMeasured by DEXA, bioimpedance, or skinfold calipers. Directly assesses fat mass vs. lean mass.
Normal range varies by age and sexFasting blood glucose, HbA1c, fasting lipid panel, uric acid. These measure what fat is actually doing to your body.
Annual check recommended for adults 40+What this means for you as a patient
If your doctor says your BMI is normal and moves on, that is a starting point, not a complete picture. Here is what to ask for:
- Have your waist circumference measured at every annual physical. It takes ten seconds and tells your doctor far more about abdominal fat than your weight on a scale.
- Request a fasting lipid panel and fasting glucose at least once if you're over 35, or sooner if you have a family history of diabetes, heart disease, or hypertension.
- Do not accept "your weight is fine" as a complete answer if you are experiencing symptoms like fatigue, increased thirst, frequent urination, or difficulty losing weight despite reasonable effort. These may signal metabolic changes that your BMI is hiding.
- Apply the Asian cutoffs to your own BMI number. If you are Filipino and your BMI is between 23 and 27.4, you are in the overweight range by Asia-Pacific guidelines and may benefit from a closer look at your metabolic markers.
The bottom line
BMI is a quick screening tool, not a health verdict. For Filipino patients especially, the standard Western BMI cutoffs underestimate metabolic risk. You can have a "normal" BMI and still have early insulin resistance, high triglycerides, or significant visceral fat accumulation.
The goal is not to obsess over any single number, not BMI, not weight, not waist size. The goal is to understand your body's actual metabolic state, and that requires more than one measurement and one moment on a scale.
