Obesity 

Definition

Obesity is a complex, chronic disorder and a number of genetic and lifestyle factors have been found to contribute to the condition. Excess body weight increases your risk of a number of diseases and health problems including heart disease, diabetes and high blood pressure. If someone is obese, their heart is working harder to pump blood around their entire body which puts pressure on the organ.

The distribution of fat is also important when assessing obesity. For example; abdominal obesity is related to a higher risk of cardiovascular disease and type 2 diabetes.

Symptoms

People with a body mass index (BMI) of 25 or more are classified as overweight. People with a BMI of 30 or greater are classified as obese.

Your BMI is calculated by dividing your weight (in kilograms) by the square of your height (in metres). For example: if you weight 90 kg and are 1.8 m tall then your BMI = 90/1.8^2 = 25. The ranges below show healthy, at risk and unhealthy BMI levels:

Underweight = Below 18.5 BMI

Normal = 18.5 – 24.9 BMI

Overweight = 25.0 – 29.9 BMI

Obese (Class I) = 30.0-34.9 BMI

Obese (Class II) = 35.0 – 39.9 BMI

Extreme obesity (Class III) = 40.0 and above BMI

Causes

Obesity occurs when you consume more calories than you burn. While there are genetic, behavioural and hormonal influences that can affect body weight, the main causes of obesity are:

• Inactivity: If you’re not active and have a sedentary lifestyle, you will not burn as many calories as you consume through exercise or normal daily activities.
• Unhealthy diet and eating habits: If you have an unhealthy diet full of junk food and/or soft drinks or high calorie drinks, weight gain is inevitable. 
  

 Diagnosis 

The best way to detect whether you are obese is to calculate your BMI. If you are in the obese range, your doctor may want to perform some further tests to determine how much weight you need to lose and what health conditions you are at risk of. These tests include:

• Taking your health history
• Doing a general physical exam
• Measuring your waist circumference
• Checking for other health problems like high blood pressure or diabetes
• Blood tests

Treatment

The goal of obesity treatment is to lose and maintain a healthy weight. All reputable weight-loss programs require lifestyle changes through eating habits and physical activity and will be tailored to suit individual needs. Treatment tools include:

• Dietary changes
• Increase in physical exercise
• Behaviour therapy such as counselling or support groups
• Weight loss surgery (this is a last resort) 

Prevention

It is important to be mindful of the ways you can prevent excess weight gain whether you are a healthy weight or at risk of obesity. The steps to prevention include:

• Exercise regularly
• Eat a healthy diet
• Avoid foods and beverages high in saturated fats, trans-fats and sugar
• Monitor your weight 

Research into Obesity