Overweight and obesity are strongly correlated with an increased risk of developing various chronic diseases, including diabetes, hypertension, cardiovascular diseases, cancer, and sleep apnoea, which can even lead to premature death. Body Mass Index (BMI) and body fat percentage are commonly used metrics to assess an individual's weight status and body composition. Understanding these measures is crucial in identifying potential health risks and taking proactive steps towards maintaining a healthy weight.
BMI is an indicator of relative weight to height. It is a strong predictor of health risk, and can be calculated with the following formula:
Individuals with a higher Body Mass Index (BMI) are at a significantly increased risk of developing obesity-related health conditions. These conditions include but are not limited to type 2 diabetes, hypertension, cardiovascular diseases, certain types of cancer, and sleep apnoea. Higher BMI often indicates excessive body fat, which contributes to the development and progression of these chronic diseases. Understanding the implications of a high BMI is essential for taking preventive measures and making informed lifestyle choices to improve health outcomes and reduce the risk of obesity-related complications.
BMI |
Asian, Caribbean, African |
Caucasian |
Underweight |
<18.5 |
<18.5 |
Normal |
18.5 - 22.9 |
18.5 - 28.9 |
Overweight |
23.0 - 24.9 |
25.0 - 29.9 |
Obese |
≥25.0 |
≥30.0 |
While BMI is a widely used measure, it has limitations as it does not distinguish between body fat and lean tissue. A more precise method for measuring body fat is Bioelectrical Impedance Analysis (BIA). BIA is a reliable and quick technique for assessing body components, including total body water, body fat mass, muscle mass, and mineral mass. This method works by applying a small alternating current to the body, which detects the water and electrical resistance levels, providing accurate measurements of the various body compartments.
Below are the reference ranges of body fat percentage recommended for men and women in different age groups.
Age |
Men |
Women |
18 - 29 years |
14 - 20% |
17 - 24% |
>30 years |
17 - 23% |
20 - 27% |
Maintaining a healthy weight is essential for overall well-being and significantly reduces the risk of chronic diseases such as diabetes, hypertension, cardiovascular diseases, cancer, and sleep apnea. Understanding and utilising metrics like BMI and body fat percentage can help individuals identify potential health risks and make informed lifestyle choices. While BMI is a useful indicator of weight status, it is important to consider its limitations and complement it with other measures, such as Bioelectrical Impedance Analysis (BIA), to get a comprehensive view of body composition. By monitoring these metrics and making necessary lifestyle adjustments, one can work towards achieving and maintaining a healthy weight, thereby promoting long-term health and reducing the risk of serious health complications.