At which BMI level is waist circumference not applicable?

Waist circumference becomes less applicable as a measure of health risk in individuals with a very high body mass index (BMI). When the BMI reaches levels such as 35.0 or higher, waist circumference does not provide additional risk information because individuals at this level are already classified as being at significantly increased risk for obesity-related health issues regardless of the distribution of fat.

At this high BMI, the individual's overall weight status predominates the effects of waist circumference. Thus, while waist circumference is useful for assessing health risk in lower BMI ranges, it becomes redundant in higher BMI classifications where the risks associated with health have already escalated significantly. This makes waist circumference measurements less relevant for further risk stratification in those with a BMI of 35.0 or higher.