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Dr. Dheeraj Naik
Internal Medicine


Obesity is characterized by having an excess amount of body fat. The two terms, obesity and overweight, are often simultaneously used, but they are both different. A person is overweight if they weigh higher than what is considered normal for their age and height. However, muscle, bone, fat and body water all contribute toward a person’s weight; obesity develops over time.

Obesity is a worldwide health concern. It has been reported that >1.9 billion of the world population is overweight, and ~650 million are obese. In India, the prevalence of obesity is increasing at a steady rate, with >135 million of its population falling under the category of obesity.

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Obesity can be divided into the following type with the help of body mass index (BMI). BMI determines weight with respect to the height of the person.

  • Overweight (not obese): BMI between 25 and 29.9

  • Class 1 (low-risk) obesity: BMI between 30 and 34.9

  • Class 2 (moderate-risk) obesity: BMI between 35 and 39.9

  • Class 3 (high-risk) obesity: BMI equal to or greater than 40

Causes And Risk Factors

When the amount of calories consumed by a person is greater than the amount of energy they burn each day, it results in obesity. This can occur because of a number of reasons:

  • Environmental Factors: Lifestyle choices such as the food type consumed by a person and their activity level influences the weight.

  • Psychological Factors: Emotions play an important role while making food choices. Individuals tend to eat more when they are sad or happy. Depression, anxiety, and boredom can trigger the emotional side of food, leading to overeating.

  • Genetic Factors: Family history of obesity increases a person’s risk of becoming obese.

  • Medical Conditions: Certain medical conditions such as hypothyroidism, depression and Cushing’s syndrome reduces a person's metabolism, which in turn leads to obesity.

  • Medications: Obesity can be the side effect of certain drugs such as anti-depressants and steroids.


Calculating BMI is the most commonly used method for diagnosing obesity. The waist circumference is measured for determining abdominal obesity. A waist size if >94 cm in men and >80 cm in women is defined as abdominal obesity.


Weight loss is not a short term thing; one needs to think about the long-term approaches of maintaining a healthy weight. This can be achieved only by making nutritional changes, lifestyle and behaviour.

Nutritional Management

It is difficult to suddenly change one’s eating habits; however, making small dietary changes to everyday food habits can make considerable difference. Eating a low-calorie diet and incorporating more fruits and vegetables into one's diet can help one lose weight.

Physical Activity

Performing regular physical activity can help one maintain a healthy lifestyle along with losing weight. Adults should perform at least 150 min of physical activity per week. Small changes in daily activities such as taking the stairs rather than the elevator improve fitness. Note that 30 min of daily aerobic exercises are recommended. This includes:

  • Jogging

  • Bicycling

  • Swimming

  • Walking

  • Rowing

Physical activities alone may not give the desired result. To get maximum benefit, combine physical activities with a low-calorie diet.

Weight Loss programs

Joining a commercial weight loss programs allows the patient to choose from a wide range of options they feel is best suited for them and will be easy to incorporate into their daily lifestyle. Such programs provide emotional and social support to patients.


Some patients opt for weight loss surgery (Bariatric Surgery). Surgery should be considered when all other non-clinical weight management options have failed.

Bariatric surgery is broadly classified into two:

  • Roux-en-Y gastric bypass: This procedure involves decreasing the size of the stomach and bypassing a part of the small intestine. As the stomach size is reduced, it helps one feel full faster. Because a part of the small intestine is bypassed, it does not absorb many calories from the food. Gastric bypass ensures long-term weight loss (60%-80% weight loss). Long-term vitamin deficiencies are one of the disadvantages of this surgery type.

  • Sleeve gastrectomy: In this procedure, 80% of the stomach is removed; hence, it limits the amount of food that the stomach can retain. One of the disadvantages of this surgery is that it is non-reversible, thereby leading to long-term vitamin deficiencies.

After surgery, if proper nutrition and lifestyle changes are not followed, the patient can gain weight.


Medications can help in losing weight only when they are used along with diet and exercise. They should be only used in patients who have failed to achieve weight loss with exercise and diet. Prescription drugs are approved for the following category of patients:

  • Patient with a BMI of >30 kg/m2

  • Patients with a BMI of >27 kg/m2 along with other comorbid conditions such as hypertension and type 2 diabetes

Weight loss drugs work by reducing the patient’s appetite, thereby creating a feeling of fullness. Most drugs are approved for short-term use by the FDA.

Prognosis And Complications

Over time, obesity paves the way for a number of health complications. If not controlled early, it can lead to the following medical conditions:

  • Hypertension: There is a strong link between obesity and prevalence of high blood pressure. Waist circumference can be used to determine the risk of hypertension for obese patients.

  • Diabetes Mellitus: People who are obese are at a higher risk of developing type 2 diabetes mellitus. The main reason behind this is thought to be insulin resistance.

  • Cardiovascular Diseases: In obese patients, the total blood volume and cardiac output is higher, leading to greatly increased cardiac workload. Obesity greatly increases the chances of developing cardiovascular diseases. Abdominal obesity increases this risk.

  • Dyslipidemia: Obesity increases the levels of triglycerides in the body and reduces high-density lipoproteins, which leads to dyslipidemia. Insulin resistance is primarily the reason behind this.

  • Cerebrovascular Diseases: The risk of stroke is higher in patients who are obese. Abdominal obesity can be used as a significant predictor of stroke in such patients.

  • Osteoarthritis: Obesity impacts the musculoskeletal system, which can lead to osteoarthritis. In patients already suffering from osteoarthritis, obesity quickens the disease progression.

  • Sleep Apnea: Obesity increases the risk of sleep apnea, which is a condition in which the person stops breathing for a certain time period while sleeping

Obesity can lead to certain types of cancer, gout, metabolic and reproductive diseases.


There is no specific approach to prevent obesity. The combination of physical exercise and healthy eating is the key to avoid weight gain.


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