BMI and Body Fat Percentage: What to Know

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.

Body Mass Index (BMI)

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:

BMI= Weight (kg)/ Height (m)2

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 Reference Range for the Adult Population

Advice for BMI

1. If the BMI is above normal, a weight loss programme is recommended to reduce the risk of comorbidities associated with obesity.
2. If the BMI is below normal, it is recommended that one increase weight or, if the condition is not too severe, prevent further weight loss.
3. People with low body weight tend to be more susceptible to infection as they may have weaker immune systems. Low body weight can also cause other health complications, such as amenorrhea in women or osteoporosis.
4. In addition, being severely underweight can also indicate other underlying diseases, which, if not treated early, can become life-threatening.
   
   

Body Fat Percentage

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.

Body Fat Percentage Reference Range

Below are the reference ranges of body fat percentage recommended for men and women in different age groups.

Advice for Body Fat Percentage

1. If the body fat percentage is within the reference range of a specific age group, try to maintain this with a healthy, balanced diet and regular physical activities.
2. If the body fat percentage is above the reference range of a specific age group, the person is suggested to attain a healthy weight by managing weight and increasing activity levels to enhance muscle mass and burn off the extra fat.
3. A certain level of body fat is needed to maintain our body functions. Fat is a storage form of energy. It is required to produce hormones and digestive enzymes and acts as a medium for absorbing fat-soluble vitamins. It protects the vital organs, keeps us insulated, and maintains our body temperature. Therefore, an extremely low body fat percentage does not necessarily mean healthy. Elite sportsmen or physically active people may have higher muscle mass and relatively lower body fat percentages.
4. The waist–hip Ratio indicates whether a person has central obesity or excessive abdominal fat, which is a health risk indicator. Risks include diabetes and cardiovascular disease, among others. This is used with BMI and Body Fat Percentage to assess an individual’s health risk. For more information, check out Waist Measurements for Central Obesity.
   
   

A Glossary of Body Composition and Health Metrics

BMI Body mass index

• An indicator relative of weight to height.

Basal Metabolic Rate

• This is the basic energy requirement to carry out basic body functions. It does not take into account the energy needed for daily activity.

Body Fat Mass

• The total body fat weight

Percent Body Fat (PBF)

• The fat percentage is obtained when fat mass is divided by total body weight. Usually, women's percentage of fat is higher than that of men.

Total Body Water

• Total Body water is the amount of water in the body

Visceral Fat Level

• It is the rating of central obesity, the fat stored within the abdominal cavity that wraps around the vital internal organs. A high visceral fat level is associated with a higher risk for heart disease, diabetes, stroke, high cholesterol, fatty liver and certain cancers.

Achieving and Maintaining a Healthy Weight: Key to Long-Term Health

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.