Body Weight and Body Composition Blog- Featured Image

Do you have a love-hate relationship with your scale? Maybe you feel validated when the number is lower and reconsider your choices when it is higher. But what if I told you that your scale is lying to you? What if I told you that your body weight is not the best measure of your health and fitness? In fact, there is something that matters much more than your weight; your body composition. 

What is body composition? 

Body composition describes the proportion of fat and non-fat mass in your body. Non-fat mass includes muscle, bone, water, and organs. Fat mass includes essential fat that is vital for normal body functions, and stored fat that serves as an energy source. An ideal body composition tends to be high in muscle mass while maintaining enough body fat for healthy function.  

Why is body composition important for health? 

Body composition is important for health because it can affect your risk of developing chronic diseases such as diabetes, heart disease, and some forms of cancer. This is particularly true of excess fat around the abdomen which can increase inflammation and impair the function of hormones directly leading to these chronic conditions. On the other hand, having a higher percentage of muscle mass can improve your metabolism, strength, endurance, posture, and immune system.  

How can you measure your body composition? 

  • Body mass index (BMI): This is a ratio of your weight to your height. It is a widely used indicator of your weight status. However, it does not account for your body fat percentage versus muscle making it unreliable for measuring health. For example, Dwayne “The Rock” Johnson has a BMI of 34.3, which puts him in the obese category even though we know his ratio is high due to muscle mass. 
  • Waist circumference: This is a measure of abdominal fat around your waist and is good indicator of health risk. A waist circumference of more than 102 cm for men and 88 cm for women increases the risk of metabolic diseases like diabetes. This is important to note because if you tend to store more fat in the hips or legs, it may reflect in a higher body weight but not necessarily a higher risk of chronic disease. 
  • Bioelectrical impedance analysis (BIA): This is a device that sends a small electrical current through your body and measures how much it is resisted by different tissues. Since muscle contains more water than fat, the device is able to differentiate between the tissue and estimate how much of each you have. This method is the one used in bathroom “smart scales”, but its accuracy can be affected by factors such as hydration, temperature, and food intake.  
  • Dual-energy X-ray absorptiometry (DXA): This is a scan that uses low-dose X-rays to measure the density of different tissues in your body. It can provide accurate, reliable, and detailed information about your bone mineral density, muscle mass, and fat mass. However, it is also expensive and requires specialized equipment and trained personnel; often in a hospital or clinic.  

Some tips for improving your body composition are: 

  • Eat a variety of foods that provide adequate protein, carbohydrates, and fats. Protein is especially important for building and maintaining muscle mass. General recommendations are 0.8 to 1 gram of protein per kilogram of body weight per day. However, if you are doing a lot of exercise then recommendations may be higher; work with a dietitian for personalized targets.  
  • Limit processed foods that are high in sugar, salt, and trans fats. These foods can increase inflammation and contribute to weight gain and chronic diseases. Instead prioritize whole food snacks like fresh fruits, nuts, or unsweetened yogurt.  
  • Do resistance training at least two to three times per week to build muscle strength and endurance. Resistance training involves lifting weights or using your own body weight to create resistance against gravity.  
  • Do aerobic exercises like brisk walking, jogging, dancing, or playing sports. Choose an activity that you enjoy and can do consistently, aiming for at least 150 minutes of moderate-intensity activity per week. Aerobic exercise can help you burn fat, improve your endurance, lower your blood pressure, and improve your mental health. 


Body composition is a better indicator of your health and fitness level than body weight alone. By measuring your body fat percentage and muscle mass, you can get a more accurate picture of your health risk and progress. To improve your body composition, follow a balanced diet and engage in regular resistance training and aerobic exercise. Remember that the number on the scale does not define you. Instead, focus on how you feel, how you look, and how you perform. 


Terence is a masters-trained, registered dietitian and certified exercise physiologist. His specialty lies in providing nutrition counselling for sports, digestive health, and weight management with a focus on offering recommendations to complement training goals. He earned a Bachelor of Science in Honours Kinesiology from the University of Waterloo before pursuing a second Bachelor and Masters in Nutrition from Ryerson University. Since becoming a registered dietitian, Terence has founded CS Nutrition, a practice in Toronto with a focus on counselling athletes and the general population. He also authored a cookbook titled Bodybuilding 30-minute Cookbook which provides healthy recipes for amateur bodybuilders.