premise: Weighty problem. The World Health Organization (WHO) reports that obesity has reached epidemic proportions worldwide, with three times as many overweight adults as there were 20 years ago. Almost one-quarter of the adult population of the UK are now classed as obese, and they are over-represented in their use of NHS services. The most widely used tool to assess obesity is body mass index (BMI), which divides 2 weight in kilograms by height in metres squared to give the units kg/m . A BMI of 25 or above is defined as overweight or pre-obese, and a BMI of 30 or more is defined as obese. People with a BMI of 40 or above are morbidly obese; they are at severe risk of developing co-morbidities like cardiovascular disease and type 2 diabetes, which reduce life expectancy and increase hospital stay. Patients weighing more than 20 stone are described as bariatric the word originated from the Greek word baros meaning heavy and iatrics meaning medical treatment. The large size of bariatric patients often leads to poor mobility, with implications for manual handling, equipment, beds, chairs and space. Most bariatric patients will have a BMI in excess of 40, though not all bariatric people will be morbidly obese nor will every person with a BMI over 30 be obese. For example, a six-foot-five rugby player weighing 21 stone (BMI = 35) with a muscular build and a good weight distribution might be athletic. In these larger people the waist-to-hip ratio can serve as a more reliable indicator of a weight problem. A ratio of 1.0 or more is consistent with an excess of fat around the waist and the need to lose weight. From a health perspective, maximum safe waist measurements are reported as 40 inches (102 cm) for men and 35 inches (89 cm) for women irrespective of fat distribution.
hypothesis: A patient with a waist-to-hip ratio of 1.1 is obese.