One of the most commonly used indices to compare nutritional level is the Body Mass Index (BMI). It is a measure of body fat based on height and weight that applies to both adult men and women.

How is BMI calculated?
BMI is calculated by dividing a person's weight in kilograms by their height in meters squared. The formula is:

BMI = weight (kg) / height^2 (m^2)

What do the BMI results mean?
The BMI results are interpreted as follows:

- A BMI below 18.5 is considered underweight
- A BMI between 18.5 and 24.9 is considered normal weight
- A BMI between 25 and 29.9 is considered overweight
- A BMI of 30 or higher is considered obese

Limitations of BMI:
While BMI is a useful tool for comparing nutritional level, it has its limitations. Some of them are:

- BMI does not take into account muscle mass, which weighs more than fat. As a result, athletes or people with a lot of muscle may have a high BMI even if they are not overweight.
- BMI does not take into account the distribution of body fat. People with a lot of fat around their waist are at a higher risk of health problems than people with fat in other areas of the body.
- BMI cannot be used to accurately assess the nutritional level of children, pregnant women, or older adults.

Conclusion:
In conclusion, BMI is a useful index for comparing nutritional level, but it should be used in conjunction with other measures like body fat percentage, waist circumference, and blood tests for a more accurate assessment. It is important to remember that BMI is just one tool and should not be used as the sole indicator of health.

The index that is used to compare nutritional level is called Body Mass Index (BMI), and it is derived from the weight (mass) and height of an individual. The BMI is defined as the body mass divided by the square of the body height and is universally expressed in units of kg/m2, resulting from the mass in kilograms and height in meters. It categorizes individuals as underweight, normal weight, overweight or obese based on the derived value.l