Obesity diagnosis involves not just diagnosing the presence of obesity but also its cause. It consists of differentiating it from other similar-looking conditions, personal history, physical examination and certain blood tests.

Obesity is a medical condition characterized by the excessive accumulation and distribution of fat in the body. It is classified as a medical disease and has acquired epidemic proportions worldwide.

Obesity is a medical diagnosis and diagnosing it is no rocket science. It requires the doctor to take the personal history of the patient, his family history, a physical examination, calculation of the body fat (BMI), measurement of the waist circumference, and a few pathological tests to rule out complications, if necessary.

Your body mass index (BMI) tells your weight status: whether you are underweight, of normal weight, overweight, obese, or morbidly obese.

A BMI of 30 or more classifies you as obese and beyond 35 as morbidly obese. Your obesity can be central or peripheral.

Central obesity, also known as abdominal obesity, is the deposit of excess fat around the abdomen, which has built up to the extent that it is likely to have an adverse impact on health. You become prone to various obesity complications including diabetes type 2, metabolic syndrome, and heart disease.

Central obesity is more dangerous because, in this type of obesity, the fat is accumulated around the vital organs in the abdomen. This makes it easy for the fat to leak into the bloodstream and cause obesity’s negative health effects.

Peripheral obesity is the deposit of subcutaneous fat around the hips, buttocks, and thighs. This does not pose dangers as central obesity does.

It is the obesity medicine clinician, whose help you should take to diagnose and treat this condition.

Once diagnosed, obesity needs to be treated with a modified weight loss diet, regular physical exercise, improved lifestyle habits, and if necessary medical intervention.

Differential diagnoses

However, obesity can be mistaken for other medical conditions. The differential diagnoses include:

  • Acromegaly is the thickening of the skin and soft tissues, and abnormal growth of the hands, feet, and face, caused by the excessive production of the growth hormone secreted by the pituitary gland.
  • Ascites is the excessive accumulation of fluid in the peritoneal cavity of the abdomen caused by conditions such as liver cirrhosis, cancer, heart failure, tuberculosis, pancreatitis, and blockage of the hepatic vein.
  • Iatrogenic Cushing Syndrome, caused by prolonged use of glucocorticoids, leads to fatty deposits around the abdomen, on the face, between the shoulders, and the upper back (causing a buffalo hump)

Criteria to diagnose obesity

An obese BMI requires a detailed medical history, a thorough physical examination, and a few blood tests.

Personal and family history

The doctor will take your personal history and will try to find out

  • Since when you had gained your extra pounds
  • what efforts you have made to lose them
  • your lifestyle habits vis-à-vis your eating habits, physical activity, alcohol, and smoking patterns, if present
  • Present medication, if any
  • Your family history for the presence of obesity and its complications in any family member – Genes also play a contributory role in you becoming obese.

The personal history is aimed at finding out the contributory cause of your obesity.

Physical exam

The physical examination in obesity diagnosis includes the measurement of

  • weight and height to determine your BMI,
  • vital signs such as blood pressure, pulse, temperature
  • auscultation of your heartbeats and lung sounds

Measurement of waist circumference: What is its importance in obesity diagnosis?

BMI, alone, is not sufficient to determine the extent of the risk of developing obesity-related complications. It is the amount of abdominal fat around your waist irrespective of your BMI, that will decide the degree of risk. That is why abdominal circumference becomes important.

Women with a waist circumference of more than 35 inches (80 cms) and men with a waist measurement of more than 40 inches (102 cms) harbor more health risks than people who have a smaller waistline.

The waist circumference tells you the amount of fat deposited in the abdomen. The more the circumference more is the fat and the health risks.

Waist-hip ratio (WHR)

The waist-hip ratio helps to determine and measure your central obesity. The score of this ratio also helps to measure the quantum of risk you face of developing the various complications that obesity can cause.

You should measure the waist circumference at the level of the naval in an exhaled and relaxed state. The hip measurement should be taken at the buttocks’ largest circumference.

A WHR greater than 0.8 for women and 0.9 for men indicates excess fat distribution around the abdomen (presence of central obesity). You must then make efforts to reduce your waist through exercise and dietary control. See your doctor if necessary.

If your WHR is higher than the cut-off levels mentioned above, you are at higher risk of developing the following comorbidities:

Lab and other tests in obesity diagnosis

Lab tests are conducted to determine if obesity has had any negative effects on any of your health. The tests usually recommended are:

  • Lipid profile
  • Liver function tests
  • Kidney function tests
  • Thyroid tests
  • Blood sugar tests along with HBA1c

All the above guidelines for obesity diagnosis will help the doctor to chart out a treatment plan to

  • Deal with your obesity in the most effective manner
  • Treat any complications that may have set in such as hypertension, diabetes, heart problems, and more.