| | Conditions Treatments | Obesity Is the BMI 17.8 too low? Yes, a Body Mass Index (BMI) of 17.8 is considered too low and falls into the "underweight" category. Obesity - Related Articles How to Get Back into the Community After Depression How to Create a Crossfit Routine for Women UV Waste Water Treatment Bio-Physical Impacts of Urbanization on Aquatic Ecosystems What is the medical term meaning breathlessness? Is Botox a substitute for an eye lift? Strobe Light Warnings