BMI chart from biochemistry medical reference direct book
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BMI categories WHO adult body mass index classification
Body Mass Index (BMI) Chart for Adults
Formula
[
\text{BMI}=\frac{\text{Weight in kg}}{(\text{Height in metres})^2}
]
| BMI (kg/m²) | Classification |
|---|---|
| < 16.0 | Severe thinness |
| 16.0-16.9 | Moderate thinness |
| 17.0-18.4 | Mild thinness |
| 18.5-24.9 | Normal range |
| 25.0-29.9 | Overweight (pre-obesity) |
| 30.0-34.9 | Obesity class I |
| 35.0-39.9 | Obesity class II |
| ≥ 40.0 | Obesity class III (severe obesity) |
Example: Weight 58 kg, height 1.70 m
[
BMI=\frac{58}{1.70^2}=20.1\ \text{kg/m}^2
]
This is within the normal range.
The medical library search did not identify this classification as a dedicated table in an available biochemistry textbook, so I cannot honestly cite a specific biochemistry-book page. These are the standard adult WHO cutoffs, with BMI defined as weight in kilograms divided by height in metres squared, as stated in WHO BMI guidance.
For children and adolescents, do not use the adult chart alone: BMI must be interpreted against age- and sex-specific BMI-for-age charts.
For undergraduate level
Reading File
Finding Sources
Searching PubMed
"body mass index"
Searching the Web
WHO BMI adult classification underweight obesity cutoffs
Body Mass Index (BMI)
BMI is an anthropometric index used to assess whether an adult’s body weight is appropriate for their height. It is commonly used in nutrition, community medicine, and clinical biochemistry screening.
Formula
[
\text{BMI} = \frac{\text{Weight (kg)}}{[\text{Height (m)}]^2}
]
Unit: kg/m²
Example
A student weighs 60 kg and is 1.65 m tall:
[
\text{BMI} = \frac{60}{(1.65)^2}
= \frac{60}{2.7225}
= 22.0\ \text{kg/m}^2
]
Therefore, the person has a normal BMI.
Adult BMI Classification Chart
| BMI (kg/m²) | Interpretation |
|---|---|
| < 16.0 | Severe thinness |
| 16.0-16.9 | Moderate thinness |
| 17.0-18.4 | Mild thinness |
| 18.5-24.9 | Normal weight |
| 25.0-29.9 | Overweight / pre-obesity |
| 30.0-34.9 | Obesity class I |
| 35.0-39.9 | Obesity class II |
| ≥ 40.0 | Obesity class III / severe obesity |
Undergraduate Exam Points
- BMI is also called the Quetelet index.
- It is calculated using weight in kilograms and height in metres squared.
- In adults, a BMI of 18.5-24.9 kg/m² is considered normal.
- A BMI ≥25 kg/m² indicates overweight, while ≥30 kg/m² indicates obesity.
- BMI is useful for population screening but does not directly measure body fat.
- BMI may overestimate adiposity in muscular individuals and may be less accurate in people with edema, pregnancy, or marked loss of muscle mass.
- For children and adolescents, interpret BMI using age- and sex-specific BMI-for-age charts, rather than adult cutoff values.
The formula and core adult thresholds agree with WHO BMI classification guidance.
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