Can you be sectioned for anorexia if you decide to leave hospital with a BMI of 17.5 and Is there a BMI you cannot be sectioned under?

Based on weight alone, it would be unlikely that someone with an eating disorder would be sectioned if they attempted to leave hospital with a BMI 17.5. Detaining people under the mental health act is always used as a last resort, and in order to be detained there needs to be adequate medical evidence that it is necessary.

Based on weight alone, generally a bmi at which someone may be sectioned would be ROUGHLY any where from bmi 13 and under.

HOWEVER...

Treatment should never be based on weight alone/bmi and other factors, such as blood chemistry, physical strength including heart rate etc, psychological factors i.e suicidal ideation, severe self harm should always be considered.

Meaning that, someone with a bmi of 17.5 WITH another health issue related to their eating disorder can be sectioned if it is agreed necessary to preserve life or the individuals life would be at serious risk if left to their own devices.

At any weight with any form of eating disorder, providing the individuals health is seriously compromised in some form, for example, an individual with Bulimia at a BMI 22 presents with extremely low potassium levels and refuses treatment, then this person may well be sectioned.

It is maybe more common that people sectioned for their eating disorder are at lower weights, because of the many health issues that accompany low body weight. It is important though, to recognise that ALL eating disorders are dangerous and ALL eating disorders can be life threatening, regardless of weight.

Hope that helps a tad.