BMI is one of the most widely used health screening tools in the world — and for good reason. It is fast, free, and broadly predictive of health risk. But it has real limitations. Relying on BMI alone can give you an incomplete — or even misleading — picture of your health. Here are the other metrics worth tracking.
The Limitations of BMI Alone
BMI does not distinguish between fat and muscle, does not measure where fat is distributed in the body, and does not account for age, gender, or ethnicity. A fit person with high muscle mass may have a "overweight" BMI, while someone with a normal BMI may carry dangerous levels of visceral fat around their organs.
These limitations mean that BMI is best used alongside other measures — not instead of them.
The Most Important Health Metrics Beyond BMI
Waist Circumference
Arguably more important than BMI for predicting cardiovascular risk. Fat stored around the abdomen (visceral fat) is metabolically active and dangerous. Measure at the level of your navel. Risk thresholds: over 88 cm (35 inches) for women, over 102 cm (40 inches) for men.
Waist-to-Hip Ratio (WHR)
Divide your waist measurement by your hip measurement. A ratio above 0.85 in women or 0.90 in men indicates an "apple shape" body — associated with significantly higher cardiovascular and metabolic risk than a "pear shape" (fat stored around hips and thighs).
Blood Pressure
High blood pressure (hypertension) is one of the most dangerous and most common conditions globally — and one of the least symptomatic. Normal is below 120/80 mmHg. Regular monitoring is essential, especially as you age. Many pharmacies offer free blood pressure checks.
Blood Glucose (Blood Sugar)
Elevated fasting blood glucose indicates insulin resistance — a precursor to type 2 diabetes. Many people have prediabetes for years without knowing it. A fasting glucose below 5.6 mmol/L (100 mg/dL) is normal. This is tested with a simple blood test from your doctor.
Cholesterol Levels
A lipid panel measures LDL (bad cholesterol), HDL (good cholesterol), and triglycerides. High LDL and triglycerides with low HDL is a dangerous combination for heart health. This simple blood test, available from your GP, gives a much clearer picture of cardiovascular risk than BMI alone.
Muscle Mass and Grip Strength
Muscle mass declines with age — a process called sarcopenia — and low muscle mass is strongly associated with poor health outcomes in older adults. Grip strength (measured with a dynamometer) is surprisingly predictive of overall health and longevity. Strength training helps preserve muscle mass at any age.
Resting Heart Rate
A lower resting heart rate generally indicates better cardiovascular fitness. Normal is 60 to 100 beats per minute. Athletes often have resting heart rates below 60. A consistently high resting heart rate (above 100) can indicate stress, dehydration, or underlying conditions worth investigating.
What Matters Most After 50
The list of useful metrics is long. After 50, three of them carry most of the weight — and they are not the ones most people track.
1. Waist circumference
After menopause, where the fat sits matters more than how much of it there is, and the waist is the number that measures that directly. Measure at the midpoint between your lowest rib and the top of your hip bone, after breathing out normally, and track it monthly rather than daily.
2. Waist-to-height ratio
Divide your waist by your height. Under 0.5 is the target. It needs no chart, no age band and no scale, which is exactly why it works — and it tracks the risk that BMI is most likely to miss after 50.
3. Strength, not weight
Lean muscle mass falls with age and falls faster after menopause. It is the tissue that keeps resting energy expenditure up, keeps blood sugar handled, and keeps you upright and independent. A measure as crude as how many times you can stand up from a chair in 30 seconds, or how much you can lift for eight repetitions, tracks something BMI cannot see at all — and it responds to training at any age.
If you track only one thing, make it the waist. If you track two, add strength. Weight is the third number, not the first.
How to Track These Metrics
You do not need expensive equipment to track most of these. Waist circumference requires only a tape measure. Blood pressure monitors are inexpensive and available at most pharmacies. Blood tests for glucose and cholesterol are routine — ask your GP for a health check if you have not had one recently.
Many modern smartwatches also track resting heart rate continuously, providing useful trend data over time.
Start With Your BMI
BMI is still a valuable first step. Calculate yours now for free — then build a fuller picture with the metrics above.
Calculate Your BMIThe Complete Health Picture
Good health is multidimensional. BMI, waist circumference, blood pressure, blood sugar, cholesterol, muscle mass, and resting heart rate each tell you something different. Together, they paint a far more accurate and useful picture than any single number alone.
The goal is not a perfect score on any one metric — it is a consistent pattern of healthy choices that improves multiple markers over time.
Read next: how to act on these numbers in practice, and what actually changes through perimenopause and menopause.