Body Shape
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Scenario
ABSI and Mortality Risk
Understand how the A Body Shape Index predicts all-cause mortality. Learn what your ABSI Z-score means for your health risk.
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Your Measurements
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cm
Your Body Shape
Shape
WHR
Waist-to-Hip Ratio Scale
0.89
- 0.5
- 0.8
- 0.95
- 1.3
WHR Position vs Shape Classification
| Shape | WHR Range (Male) | Description |
|---|---|---|
| Pear | < 0.85 | Narrower waist relative to hips |
| Rectangle | 0.85 – 0.95 | Straight torso, similar waist and hips |
| Triangle | 0.95 – 1.0 | Waist slightly wider than hips |
| Apple | > 1.0 | Higher abdominal fat distribution |
What this means: Relatively straight torso — waist and hips are similar in width.
The formula
The formula
What WHR-Based Body Shape Classification Measures
Body shape classification uses the waist-to-hip ratio (WHR) — the circumference of your waist divided by the circumference of your hips — to categorize how your body distributes fat. This classification system is rooted in anthropometric research that links fat distribution patterns to metabolic and cardiovascular risk. Unlike overall weight, where fat is stored on your body has a significant impact on long-term health outcomes.
The concept of body shape typing dates back to the 1940s when psychologist William Sheldon introduced somatotypes (endomorph, mesomorph, ectomorph). The modern WHR-based approach was popularized by the World Health Organization (WHO) as a practical screening tool for abdominal obesity. It provides a simple, non-invasive way to estimate whether an individual carries more fat around the abdomen (apple-shaped) or around the hips and thighs (pear-shaped), with different implications for health risk.
The Body Shape Formula
Body shape is determined by calculating your waist-to-hip ratio (WHR) and then mapping the result to gender-specific classification thresholds. The WHR formula is:
WHR = Waist (cm) ÷ Hip (cm)
Male classification: < 0.85 = Pear (Triangle) | 0.85–0.95 = Rectangle | 0.95–1.0 = Triangle (Inverted) | > 1.0 = Apple
Female classification: < 0.75 = Hourglass | 0.75–0.80 = Pear (Triangle) | 0.80–0.85 = Rectangle | > 0.85 = Apple
The same measurement procedure applies regardless of gender. Waist circumference is measured at the narrowest point of the torso (typically just above the belly button), and hip circumference is measured at the widest point around the buttocks. Both measurements should be taken with a non-stretchable tape measure, snug but not compressing the skin.
Formula Source
This classification uses the **WHO waist-to-hip ratio thresholds** from the **World Health Organization's "Waist Circumference and Waist–Hip Ratio: Report of a WHO Expert Consultation"** published in **2008**.
Reference URL: https://www.who.int/publications/i/item/9789241501491
Last Verified: 2026-07-30
Worked Example
A woman has a waist circumference of 72 cm and a hip circumference of 96 cm. Her WHR is 72 ÷ 96 = 0.75. According to the female classification thresholds, a WHR of 0.75 falls at the boundary between Hourglass (< 0.75) and Pear (0.75–0.80). This means she has a relatively low waist-to-hip ratio, indicating fat storage predominantly around the hips and thighs rather than the abdomen — a pattern associated with lower cardiovascular risk.
As another example, a man with a waist of 98 cm and hips of 94 cm has a WHR of 98 ÷ 94 = 1.04. This places him in the Apple category (> 1.0), indicating a higher proportion of abdominal fat, which is associated with elevated cardiometabolic risk.
Body Shape Classification Table (WHO-Based)
| Shape | Male WHR | Female WHR | Fat Distribution |
|---|---|---|---|
| Hourglass | — | < 0.75 | Balanced fat distribution between upper and lower body; narrow waist relative to bust and hips. |
| Pear (Triangle) | < 0.85 | 0.75 – 0.80 | Fat stored predominantly in hips, thighs, and lower body. Associated with lower cardiovascular risk. |
| Rectangle | 0.85 – 0.95 | 0.80 – 0.85 | Relatively even fat distribution; waist and hips are roughly similar in circumference. |
| Triangle (Inverted) | 0.95 – 1.0 | — | Wider shoulders relative to hips; fat stored more in the upper body and trunk. |
| Apple | > 1.0 | > 0.85 | Fat concentrated around the abdomen. Associated with higher risk of metabolic and cardiovascular conditions. |
Why Body Shape Classification Alone Is Not a Full Picture
Body shape classification based on WHR is a useful screening tool, but it has important limitations. It tells you where fat is distributed but not how much total body fat you carry. A person with a pear shape may still have excess overall body fat, while an apple-shaped person with otherwise healthy body composition may be incorrectly flagged as high risk. WHR also does not distinguish between subcutaneous fat (under the skin) and visceral fat (around the organs), with the latter being the more metabolically harmful type.
Additionally, body shape classification thresholds were developed primarily from European-origin populations. Some studies suggest that optimal cut-points may differ for Asian, African, and Indigenous populations. Age also affects fat distribution — older adults tend to accumulate more abdominal fat regardless of their body shape classification in younger years.
Known Limitations
- WHR does not differentiate between visceral and subcutaneous fat — two types with very different metabolic impacts.
- Body shape classification is not a direct measure of body fat percentage; two people with the same WHR can have very different total body fat levels.
- Measurement accuracy depends on consistent tape placement. Small errors in measuring waist or hip circumference can change the shape classification.
- Pregnancy, recent childbirth, and certain medical conditions (e.g., ascites, fibroids) can alter waist circumference and produce misleading WHR values.
- Body shape categories are culturally influenced and may not capture the full diversity of human body morphology across ethnic groups.
- WHR alone says nothing about diet quality, physical activity level, muscle mass, or other lifestyle factors that contribute to overall health.
Scenario guide
Scenario guide
What the research shows
The landmark 2013 study by Krakauer and Krakauer, published in the Proceedings of the National Academy of Sciences (PNAS), analyzed data from nearly 100,000 participants in the NHANES database. They found that ABSI was a stronger predictor of all-cause mortality than BMI, waist circumference, or waist-to-height ratio — and this held true across all BMI categories.
How ABSI predicts mortality
ABSI captures the excess mortality risk associated with central obesity — fat stored around the waist — independent of overall weight. Even among people with a "normal" BMI, those with a high ABSI (indicating disproportionate waist size for their height and weight) had significantly higher mortality rates.
Understanding your ABSI Z-score
- −0.4 to −0.2: Significantly lower mortality risk than average for your age and sex
- −0.2 to +0.2: Average mortality risk
- +0.2 to +0.4: Elevated mortality risk
- above +0.4: Significantly elevated mortality risk
Why ABSI outperforms BMI for mortality prediction
BMI cannot distinguish between muscle and fat, and it does not account for where fat is stored. ABSI captures central fat distribution — the type most strongly linked to cardiovascular disease, metabolic disorders, and premature death. Two people with identical BMIs can have very different ABSI values and very different mortality risks.
Limitations
ABSI is a statistical tool, not a crystal ball. It predicts population-level risk, not individual outcomes. Genetics, lifestyle, access to healthcare, and other factors all influence individual mortality risk. Use ABSI as one input among many for understanding your health.
FAQ
Frequently Asked Questions
Yes. The 2013 PNAS study of nearly 100,000 participants found ABSI was a stronger predictor of all-cause mortality than BMI, waist circumference, or waist-to-height ratio across all BMI categories.
An ABSI Z-score above +0.2 indicates higher-than-average mortality risk for your age and sex. Above +0.4 indicates significantly elevated risk.
Yes. If you have a normal BMI but a disproportionately large waist for your height and weight, your ABSI will be high and your mortality risk elevated — even though BMI alone would suggest low risk.
ABSI predicts population-level risk trends, not individual outcomes. Genetics, lifestyle, and healthcare access all influence individual mortality. Use it as a general health indicator, not a definitive prediction.
Reducing central fat through diet, cardio exercise, strength training, and stress management will lower your waist circumference and improve your ABSI. Even modest reductions of 2-3 cm can make a difference.
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