disorders of nutrition
Obesity
Diagnosis of Obesity
Body mass index (BMI) Waist circumference Determination of body composition Obesity is diagnosed by determining the body mass index ( Obesity ). However, BMI has some limitations. The BMI does not take sex and age into consideration and makes only a few adjustments based on ethnic group. For people who are of Asian descent and some other ethnic groups, the BMI that is considered overweight is slightly lower. Also, the BMI does not distinguish between lean and fat tissue. Therefore, doctors may be unsure whether a high BMI is due to muscle (for example, in body builders) or excessive fat. In such cases, they determine body composition (the percentage of body fat and muscle). Diagnosis is measured. This measurement helps identify and quantify abdominal (visceral) obesity, which is fat that accumulates around the waist and in the abdomen. Abdominal obesity is much more harmful than fat that is distributed throughout the body under the skin (subcutaneous fat). Knowing how large the waist is and whether metabolic syndrome is present helps doctors estimate the risk of certain complications (such as heart disorders) better than knowing what the person's BMI is. Body composition(the percentage of body fat and muscle) can be determined using the following: Measurement of skinfold thickness and the circumference of the upper arm Bioelectric impedance, which can be done in a doctor’s office Underwater (hydrostatic) weighing Skinfold thickness is usually measured over the triceps, at the back of the upper arm. The skinfold is the skin and layer of fat under it that are measured by pinching the skin. Bioelectrical impedance analysis estimates the percentage of total body water directly and determines the percentage of body fat indirectly. It is most reliable in healthy people and in people with only a few chronic disorders, such as moderate obesity or Diabetes Mellitus (DM) . Underwater weighing is the most accurate method for measuring percentage of body fat. However, it is costly and time-consuming. Thus, it is used more often in research than in clinical care. Men are considered to have obesity when the body fat level is > 25%. In women, the level is > 32%. Typically, blood tests are done. Blood sugar (glucose) is measured to check for Prediabetes or Doctors also check for other disorders that are common among people who have obesity, such as Sleep Apnea , 