BMI and intermittent fasting: what a calculator cannot decide
The short answer
BMI cannot decide whether fasting is suitable or prescribe an eating window. A change in BMI describes a mathematical change in weight and height, not proof that a diet is safe or effective for a person. This tool gives no fasting plan, treatment or weight-loss deadline.
BMI cannot decide whether fasting is suitable or prescribe an eating window. A change in BMI describes a mathematical change in weight and height, not proof that a diet is safe or effective for a person. This tool gives no fasting plan, treatment or weight-loss deadline.
At a fixed height, a lower weight produces a lower BMI mathematically. This does not establish whether weight loss is appropriate for an individual, how it should be achieved, or a safe timetable. Recheck consistent measurements and discuss personal interpretation with an appropriate healthcare professional. This calculator does not prescribe diets, exercise or treatment.
How we calculate
Body mass index (BMI) is weight in kilograms divided by height in metres squared. It is one screening measure, not a diagnosis or a direct measurement of body fat.
Imperial inputs are converted using 1 lb = 0.45359237 kg and 1 in = 2.54 cm. Five feet nine inches is 69 inches, not 5.9 feet.
Units are converted before calculation. Categories use the unrounded result; only the display is rounded. The shortcut multiplier 703 can differ slightly from exact conversion.
Screening scope
Adult (20+), not pregnant. For ages 2–19, use a validated BMI-for-age calculator. This tool shows adult ranges only.
BMI is one screening measure, not a diagnosis or a weight goal. It does not distinguish muscle from fat and is not suitable for pregnancy.
This explanation checks the method and arithmetic. It does not claim an independent medical review. Personal interpretation requires context and an appropriate healthcare professional.
Sources
Sources below are in English.