Waist circumference or body mass index: which is more informative?

When assessing the risk of type 2 diabetes, hypertension, and cardiovascular disease, body mass index alone is insufficient: waist circumference and, especially, waist-to-height ratio provide additional information about central, or abdominal, obesity. However, the most informative practical approach is not to choose between waist circumference and body mass index, but to use them together. A recent review from 2026 shows that when both indicators are analyzed simultaneously, waist circumference is often a stronger predictor of adverse outcomes, but their combination allows for better differentiation between obesity types and their associated risks. [1]

Body mass index is convenient for initial screening: it quickly shows the relationship between weight and height and is well standardized. However, it does not distinguish fat from muscle and does not indicate the location of fat tissue. Waist circumference better reflects fat accumulation in the abdominal region, including visceral fat, which is particularly important for cardiometabolic risk. [2]

This position is increasingly reflected in modern recommendations. NICE, in its 2025 guidance, recommends using waist-to-height ratio alongside body mass index for adults with a body mass index below 35 kg/m². The 2025 Lancet Diabetes & Endocrinology Commission went even further: it proposes using body mass index primarily as a screening indicator, and confirming the presence of excess body fat with additional anthropometric measurements—for example, waist circumference, waist-to-height ratio, or waist-to-hip ratio—except for people with a very high body mass index. [3]

What do body mass index and waist size actually measure?

Body mass index (BMI) measures how much a person weighs relative to their height, while waist size measures how much body fat is concentrated in the center of the body. These are related, but not identical, characteristics.

Body mass index is calculated using the formula:

Weight in kilograms / height in meters².

For example, with a weight of 90 kg and a height of 1.80 m:

90 / 1.80² = 27.8 kg/m².

For most adults, traditional classification considers 18.5–24.9 kg/m² to be in the normal weight range, 25–29.9 to be overweight, and values over 30 kg/m² to be obese. These limits remain a widely used practical tool, although current guidelines increasingly emphasize the need to interpret them in the context of body composition, ethnicity, and other factors.[4]

Waist circumference measures the size of the abdomen at a specific anatomical point. It is not a direct measurement of visceral fat: a tape measure cannot distinguish subcutaneous fat from the fat around the internal organs. However, at the population level, a large waist is a fairly good indicator of abdominal fat accumulation and can complement the information obtained from the body mass index. [5]

It is the difference between total body mass and fat distribution that explains why two people with the same BMI can have different metabolic risk.

Why belly fat is especially important

Not all adipose tissue is physiologically equivalent. Given the same overall body weight, significant central obesity is typically associated with a more unfavorable cardiometabolic profile.

Visceral adipose tissue is located within the abdominal cavity around the organs. Its excess is closely linked to insulin resistance, lipid metabolism disorders, and other metabolic changes. This is why the European Association for the Study of Obesity, in its new 2024 diagnostic approach, specifically identified abdominal fat accumulation as an important risk factor that body mass index alone may miss. [6]

The international consensus on visceral obesity also emphasizes that within a given BMI category, individuals with larger waist circumferences have a higher risk of adverse outcomes. Adding waist circumference allows us to identify a riskier phenotype that is not evident from weight and height alone. [7]

In a meta-analysis of 72 prospective cohorts including over 2.5 million people, central obesity remained associated with all-cause mortality even after controlling for body mass index. For example, a 10-cm increase in waist circumference was associated with a higher risk of all-cause mortality in a pooled analysis. These observational data do not prove that waist circumference alone is a direct cause of death, but they do confirm the independent prognostic value of central obesity. [8]

So, what is more informative - waist or body mass index?

The answer depends on the question.

Task	A more useful indicator	Why
Rapid weight-to-height screening	Body mass index	Simple, standardized, widely used
Assessment of central obesity	Waist circumference	Better reflects fat accumulation in the abdominal area
Cardiometabolic risk assessment	Waist + Body Mass Index	Their combination is more informative than a single indicator.
Comparison of people of different heights	Waist-to-height ratio	Takes body size into account
A very muscular man	Waist and body composition are more important than BMI alone	High BMI may be linked to muscle mass
An elderly man	BMI alone is not enough	Muscle loss is possible with preserved or increased fat mass.
Identification of underweight	Body mass index is more useful	Waist measurement is not intended to diagnose underweight.
Weight loss control	Weight/BMI + waist	Allows you to see both overall weight loss and changes in abdominal fat

A recent review from 2026, specifically comparing these two measures, reached this conclusion: waist circumference and body mass index characterize different components of obesity, and their combined use allows for better identification of individuals at increased risk. When statistically modeling both continuous measures simultaneously, the association between waist circumference and adverse outcomes often remains stronger. [9]

So, the question "which single number is better?" for an adult interested in metabolic health can be answered: waist size often provides more information about risk than BMI alone; but the two are most informative when taken together.

Why a normal body mass index does not guarantee low risk

A person can have a body mass index of 23-24 kg/m² and at the same time have significant fat accumulation in the abdominal area.

Body mass index does not differentiate between muscle, fat, and bone tissue and does not reflect fat distribution. Therefore, a person's weight may be formally within the normal range, but central fat tissue is quite prominent. The literature uses terms such as "normal weight with central obesity" or "normal-weight obesity," although the definitions of these conditions vary between studies. [10]

It is in this situation that waist measurement is particularly useful. The consensus of the International Atherosclerosis Society and the Visceral Obesity Working Group notes that waist measurement can detect increased risk within different BMI categories, including those with relatively low BMI values. [11]

NICE therefore specifically warns that even the 'healthy' BMI category does not exclude central obesity.[12]

That is:

BMI 23 ≠ automatically no excess abdominal fat.

A high body mass index does not always mean excess fat.

The reverse error is also possible.

The body mass index (BMI) measures kilograms but doesn't understand what they're made up of. A person with significant muscle mass—for example, a strength athlete—may fall into the "overweight" range, or even sometimes into the obese range, despite having a relatively small amount of body fat. Modern reviews explicitly include developed musculature within the known BMI limits. [13]

NICE recommends that body mass index be interpreted with caution in adults with high muscle mass.[14]

Let's imagine two men of the same height:

First: 95 kg, strength training, waist 84 cm.

Second: 95 kg, moves little, waist 110 cm.

Their body mass index will be the same.

However, tissue distribution and cardiometabolic profiles can vary significantly. This is why a single BMI number cannot provide a complete individual assessment.

Why waist size is sometimes more informative than BMI

If the body mass index is already known, the waist provides new information: where the excess weight is located.

This is clearly evident in statistical models. The International Waistline Consensus noted that after BMI was included in the model, the association between waistline and morbidity and mortality persisted and often became stronger. In other words, two people with the same BMI but different waistlines have different risks. [15]

A 2026 review confirmed this finding with current evidence: when waist circumference and BMI were used together as continuous variables, waist circumference consistently remained a stronger predictor of a range of adverse outcomes, while the BMI association weakened or reversed direction.[16]

This doesn't mean that the body mass index has become useless. Rather, it answers a different question.

BMI is a good indicator of overall weight relative to height.

The waistline specifies to what extent this mass is accompanied by central accumulation of adipose tissue.

Why is the waist-to-height ratio increasingly used today?

Measuring your waist is useful, but the waist-to-height ratio solves another problem: the same waist will have a different value for someone who is 150 cm tall and someone who is 195 cm tall.

The ratio is calculated very simply:

Waist/Height

In the same units.

For example:

Waist 85 cm, height 175 cm:

85 / 175 = 0.49.

Waist 95 cm with the same height:

95/175 = 0.54.

NICE recommends using waist-to-height ratio in conjunction with BMI in adults with a body mass index below 35 kg/m². For this group, the following practical interpretation is proposed:

Waist-to-height ratio	NICE interpretation
0.40-0.49	central obesity is not increased
0.50-0.59	increased central obesity and risk
≥0.60	even higher levels of central obesity and risk

The NICE rule of thumb is particularly simple: try to keep your waist less than half your height. NICE applies these categories to adults of both sexes and various ethnic groups with a BMI below 35 kg/m². [17]

If your height is 170 cm, half your height is 85 cm.

If height is 180 cm - 90 cm.

If the height is 190 cm - 95 cm.

Because of adjustment for body size, waist-to-height ratio has been shown in many studies to be slightly better at discriminating cardiometabolic risk than absolute waist circumference or BMI. A meta-analysis of over 300,000 adults found that waist-to-height ratio was superior to BMI in identifying a number of cardiometabolic risk factors. [18]

Does this mean that the "waist less than half the height" rule is universal?

This is a good screening guideline, but not a medical guarantee of health.

A ratio of less than 0.5 reduces the likelihood of severe central obesity according to NICE criteria, but does not exclude hypertension, diabetes, lipid metabolism disorders or other diseases.

A ratio above 0.5 is not a standalone diagnosis of diabetes or cardiovascular disease. It indicates that central fat accumulation deserves attention along with other risk factors. [19]

This rule also cannot be extended without reservations to pregnancy, children, or situations with a significant increase in the abdomen for other reasons.

Thus, the rule is useful specifically as a rapid adult screening test, not as a universal diagnostic test.

How to measure your waist correctly

The result depends on the measurement location, so it is important to use the same protocol.

NICE advises:

Find the lower edge of the ribs;

Find the top of the pelvic bones;

Place the measuring tape in the middle between these points;

Keep the tape horizontal;

Measure after a normal, calm exhalation. [20]

The tape should fit snugly against the body but not press into the skin.

Measuring "where it's narrowest," along the belt line, or exactly at the navel isn't always the same. International guidelines have historically used several different anatomical points, so values from different studies or medical systems may vary slightly. The World Health Organization specifically addressed this issue in an expert document on waist measurement. [21]

For home surveillance, the most important thing is to use the same equipment every time.

The difference between a waist measurement of 97 and 98 cm, resulting from the tape being two centimeters higher today, should not be interpreted as a physiological change.

What do the traditional thresholds of 88 and 102 cm mean?

The following meanings can often be found:

More than 88 cm for women;

More than 102 cm for men.

They are indeed used in a number of Western guidelines as indicators of high risk of central obesity, including American cardiology documents.[22]

But it is wrong to consider them universal for humanity.

International consensus emphasizes that optimal waist circumferences vary among ethnic groups and that using a single value independent of BMI has limitations. Values associated with increased risk vary significantly across populations. [23]

This is why the waist-to-height ratio is useful for an international audience: it partially accounts for differences in body size and allows for a simple benchmark of approximately 0.5. However, this indicator remains a screening criterion, not an absolute diagnostic one.

Why BMI thresholds don't work the same for everyone

The relationship between body mass index and body fat varies by age, sex, body type, and ethnicity.

For example, NICE indicates that people of South Asian, Chinese, other Asian, Middle Eastern, Black African, and Afro-Caribbean descent have, on average, a lower BMI and are at higher risk of developing cardiometabolic disease. This system uses a threshold of 23 kg/m² for overweight and 27.5 kg/m² for obesity for these groups, instead of the traditional 25 and 30 kg/m². [24]

This is a good example of the fundamental limitation of BMI: the same number does not always mean the same fat mass and the same risk in different populations.

However, waist circumference also has ethnically different thresholds. Therefore, the BMI problem cannot be solved by simply replacing one universal figure with another universal waist figure. [25]

The modern trend is precisely towards combined assessment.

A particular problem for older people

With age, body weight can remain almost unchanged, despite significant changes in body composition.

A person gradually loses muscle mass and simultaneously accumulates fat. As a result, weight and BMI change little, although the physiological profile becomes completely different.

Sarcopenic obesity—a combination of excess adipose tissue and decreased muscle mass and function—is especially prevalent in older adults. BMI alone can underestimate this condition. [26]

NICE therefore specifically recommends that BMI be interpreted with caution in people aged 65 years and over, taking into account medical conditions and functional status.[27]

Waist circumference adds information about abdominal fat, but it does not measure muscle.

If it is clinically important to assess sarcopenia, other parameters are needed, such as strength, physical function, and, if necessary, body composition assessment.

Does a normal waist make a high BMI safe?

No. It only changes the interpretation.

A high BMI with a relatively small waist may indicate that a significant portion of the body mass is muscle or peripheral tissue, rather than central fat. This profile often has a different cardiometabolic risk profile than the combination of a high BMI and a large waist.

But one centimeter isn't enough to consider a high BMI "healthy." Blood pressure, glucose, lipids, physical fitness, family history, and pre-existing medical conditions also play a role.

Modern diagnostic approaches to obesity are moving away from a single anthropometric number to a combination of body size + fat distribution + real health consequences. [28]

What does a large waist with a normal BMI mean?

This is one situation where the waist especially adds information.

For example, a person with a height of 170 cm and a weight of 68 kg has a BMI of:

68 / 1.70² ≈ 23.5 kg/m².

According to the traditional classification, this is a normal BMI.

If his waist is 92 cm, his waist to height ratio would be:

92 / 170 ≈ 0.54.

According to the NICE classification, this already corresponds to increased central fat mass and increased risk, despite a “normal” BMI. [29]

It's examples like these that show why the answer "I have a normal BMI, so weight is definitely not associated with risk" may be wrong.

What has changed in the understanding of obesity in 2024-2026?

Recent international documents have significantly strengthened the idea that BMI should not be the only individual diagnostic criterion.

In 2024, the European Association for the Study of Obesity introduced a new diagnostic system that takes into account not only overall BMI but also abdominal fat accumulation and the presence of medical, functional, or psychological consequences. The association recommends measuring the waist in people with a BMI below 35 kg/m² as an indicator of visceral fat accumulation and cardiometabolic risk. [30]

In January 2025, the Lancet Diabetes & Endocrinology International Commission proposed an even more fundamental change: to use BMI primarily for screening, and to confirm the presence of excess body fat with additional anthropometric measures or direct fat measurement. If the BMI exceeds 40 kg/m², the commission considers it practical to assume the presence of excess body fat without further confirmation. [31]

The commission also divided obesity into clinical, where excess adipose tissue is already accompanied by organ dysfunction or significant functional limitations, and preclinical, where excess fat is present but the corresponding disease does not yet exist. This once again demonstrates how modern diagnostics extend beyond a single weight or waist measurement. [32]

And in 2026, a review by Ross, Janssen, and Deprez directly formulated a practical conclusion: waist circumference and BMI should be considered together, as this allows for a better description of the heterogeneity of obesity and the identification of the most risky phenotypes. [33]

Does this mean that BMI is outdated?

No. Rather, the idea of using it as the sole description of individual health is outdated.

BMI has several strengths:

It is very simple;

It costs almost nothing;

Reproduces well;

Allows comparison of large populations;

Widely used in research;

It remains a practical primary screening tool. [34]

Therefore, the new recommendations do not suggest abandoning BMI.

They suggest not stopping there.

This is a significant difference.

When waist circumference can also be misleading

Waist is not a direct measurement of visceral fat.

It includes subcutaneous fat tissue, internal abdominal structures, and depends on body type. Different anatomical measurement points also yield slightly different values. [35]

Conventional thresholds are more difficult to interpret at very high BMI. This is why NICE recommends waist-to-height ratio as an additional indicator, especially for BMIs below 35 kg/m². [36]

In pregnancy, abdominal circumference is obviously not used in the usual way to assess central obesity.

Severe ascites or other conditions that significantly enlarge the abdomen also disrupt the normal relationship between waist circumference and body fat.

Therefore, the waist is not a universal diagnostic device.

Should I measure body fat percentage instead of BMI and waist circumference?

For most people, not necessarily.

A modern clinical obesity committee allows for direct assessment of adipose tissue—for example, by dual-energy X-ray absorptiometry—as one way to confirm excess fat mass. However, anthropometric measurements are much more readily available for routine initial examination. [37]

The European Association for the Study of Obesity also allows for body composition assessment when BMI and physical examination give an inconclusive picture.[38]

However, home smart scales with bioimpedance should not automatically be considered a more accurate alternative to BMI and waist measurement: the absolute individual accuracy of the calculated body fat percentage in consumer devices is limited.

For most people, a tape measure plus a standard scale provides a surprising amount of useful information if the readings are interpreted correctly.

What's best to track when losing weight?

Weight and waist at the same time.

Weight shows the change in the total mass of the body.

Waist helps us understand whether central obesity is changing.

These indicators don't always move in perfect sync. The International Waistline Consensus notes that physical activity and dietary changes can reduce waist circumference and visceral fat even with relatively small changes in overall body weight. [39]

Let's imagine that after three months a person weighs:

Was 90 kg → became 89 kg.

The scale shows that the result seems small.

But:

Waist was 104 cm → became 96 cm.

This change contains additional information that BMI alone does not show.

The opposite is also helpful: significant weight loss without the expected change in waist size can be a reason to take a closer look at the composition of the weight loss, diet, physical activity, and the accuracy of measurements.

Don't turn your waist into your new "magic number"

The transition from BMI to belly measurement should not simply replace one overly simplified system with another.

The risk of cardiovascular disease also depends on age, blood pressure, smoking, glucose, lipids, family history, physical activity and existing medical conditions.

Waist circumference does not replace these indicators.

Even the international consensus that strongly advocates for broader waist measurement notes that the question of how much its addition improves existing multivariate models of cardiovascular risk is more complex than simply associating waist with outcomes. [40]

That is, a large waist is a marker of increased risk, and not an independent prognosis of future disease.

A practical guide: which numbers to look at at home

For an adult without special circumstances, a simple sequence can be used.

First, measure your height and weight and calculate your body mass index.

Then measure your waist using the same method.

If your BMI is below 35 kg/m², it's helpful to additionally divide your waist by your height. This approach is consistent with current NICE guidelines. [41]

For example:

Height - 176 cm;

Waist - 96 cm;

Waist to height ratio is 96/176 = 0.55.

This means increased central obesity according to the NICE classification, regardless of whether the BMI is just around the normal-to-overweight limit.[42]

After this, it makes sense to consider the clinical context: blood pressure, glucose, lipids, physical activity, existing diseases and other risk factors.

What is often misunderstood

"BMI is useless." No. It is a convenient and well-standardized screening tool, especially at the population level. Its problem is its use as a single individual indicator. [43]

"Waist is always better than BMI." For central and cardiometabolic risk, it often adds more information, but for assessing overall mass, underweight, and standardized classification, BMI retains its advantages.

"A normal BMI means a normal amount of body fat." Not necessarily. Central obesity or a high percentage of body fat with a relatively normal overall weight are possible. [44]

"A high BMI means obesity in any athlete." Not necessarily. Large muscle mass can increase the index without a corresponding excess of fat. [45]

"102 cm for men and 88 cm for women are appropriate for all peoples." No. Risk thresholds vary by ethnicity, and international experts do not recommend using one set of limits as universal. [46]

"A waist less than half your height means there are no risks." No. This is only a simple indicator of central obesity, not a comprehensive health assessment.

Key points from experts

Robert Ross, PhD, is a professor of exercise physiology in the School of Kinesiology and Health Studies at Queen's University and a member of the Division of Endocrinology and Metabolism in the Faculty of Medicine. His research focuses on abdominal obesity and associated cardiometabolic risk. [47]

In a 2026 review, Ross, along with Ian Janssen and Jean-Pierre Despres, concluded that waist circumference and body mass index should be considered together. The authors note that when continuous variables are analyzed simultaneously, waist circumference remains a strong positive predictor of adverse outcomes, while the association with BMI is significantly weakened, confirming the independent value of assessing central obesity. [48]

Francesco Rubino, MD, is Professor and Head of Metabolic and Bariatric Surgery at King's College London. He chaired the Lancet Diabetes & Endocrinology International Commission on the Definition and Diagnosis of Clinical Obesity. [49]

The commission's recommendations propose abandoning the diagnosis of obesity in individuals based solely on BMI. The index is viewed as a screening tool, and excess body fat is recommended to be confirmed by additional anthropometric indicators or direct measurement of body fat; the actual consequences of excess body fat on organ function and daily activity are then assessed. [50]

Frequently Asked Questions

What is more important - weight or waist?

They answer different questions. Weight and BMI reflect overall body size relative to height, while waist size better reflects central fat accumulation. A combination of the two is more useful for risk assessment. [51]

What waist circumference is considered normal?

There is no universal centimeter value for all genders and ethnic groups. Some Western guidelines use cutoff values of 88 cm for women and 102 cm for men for high risk, but international data support the need to consider ancestry and other characteristics. [52]

What is easier to use at home?

The waist-to-height ratio is a very useful one. NICE recommends a BMI of less than 0.5 for those with a BMI below 35 kg/m²—that is, a waist less than half your height. [53]

If my BMI is 24 and I have a large waist, should I consider my weight normal?

BMI is formally within the normal range, but a large waist may indicate central obesity and higher cardiometabolic risk. Therefore, BMI alone is not enough. [54]

If your BMI is 27 and your waist is small, is it still bad?

Individual risk cannot be determined based on these two numbers alone. A small waist may indicate less severe central obesity, while a high BMI is sometimes associated with muscle mass. Additional information about health and body composition is needed.

How often should you measure your waist?

Monitoring changes doesn't usually require daily monitoring. Fat tissue changes slowly, and a slight misalignment of the tape placement can mask true progress. For long-term monitoring, a consistent methodology and comparison of results at reasonable intervals are more important.

Where exactly should I place the measuring tape?

According to the NICE method - midway between the lower edge of the ribs and the upper part of the pelvic bones, after a natural exhalation. [55]

Does a BMI of 30 always mean obesity?

According to traditional classification, for most adults, yes, but the current Clinical Obesity Commission recommends against using BMI as the sole individual diagnostic criterion. It may misclassify people with unusually high muscle mass or fail to reflect fat distribution. [56]

What shows visceral fat better?

Waist circumference is more closely related to visceral fat than BMI, but does not measure it directly. Imaging techniques are used to directly assess fat distribution, but in routine practice they are generally not needed for screening purposes alone. [57]

Is it possible to lose weight without a big change in BMI but still reduce your risk?

Yes, it is possible to reduce waist circumference and visceral fat with relatively small changes in body weight, especially with increased physical activity. Such changes may be accompanied by improvements in cardiometabolic risk factors. [58]

Main

For assessing individual cardiometabolic risk, waist circumference is often more informative than body mass index alone because it reveals central fat distribution. However, replacing BMI with waist circumference is also incorrect: the modern approach is to use both indicators together. This is consistent with both the international consensus on visceral obesity and the new reviews scheduled for 2026. [59]

For most adults, it's useful to know their BMI and waist-to-height ratio. For BMIs below 35 kg/m², NICE recommends using both measurements and using a waist measurement less than half their height as a simple marker for the absence of excess central fat mass. [60]

The main change in modern medicine is not that "BMI has been abolished," but that a single number is no longer sufficient for a complete individual assessment of obesity and its associated risks. The 2025 Lancet Diabetes & Endocrinology Commission explicitly proposed using BMI primarily for screening and confirming excess body fat with additional methods. [61]