Bodyweight literally means how heavy we are….. I am sure all of us know this. But a more important aspect which might be unknown to you is that this heaviness is a sum total of fat and lean mass contained by the body. Lean mass comprises of muscles, body fluids (blood, extra and intracellular fluid), bones and organs whereas fat mass includes fat which is stored in the body.
For a person to lead a healthy, disease-free life; the percentage of lean mass should always be higher than the fat mass percentage. But why is that? Lean mass being a hard worker produces work and burns food calories whereas fat mass is quite lazy and is a piece of excess baggage for the body.
There are numerous factors which determine lean to fat ratio for a person. Few of these include age, gender, physical activity, diet, body weight, etc.
Let us understand how these factors affect the ratio of fat and lean mass.
Age: A baby is born with high fat and low lean mass percentage. This ratio slowly changes through childhood and adolescence. Fat mass might again show an increase in adulthood because of diet and inactivity.
Gender: Females like it or not, but their body stores more fat mass than males. The percentage of lean to fat mass is 25:75 in females which is approximately 15:85 in males.
Physical Activity: A physically active person burns fat and converts this tissue into muscles leading to an increase in lean mass. Athletes and sportsperson have lower percentages of fat compared to average because they burn the fat calories (calories derived from fat sources in the diet) for energy and thus store less fat. Gender bias is present in athletes too. Male athletes have less than 10% fat and female athletes have around 15% body fat.
Diet: A high fat and high simple carbohydrate diet can lead to an increase in fat mass in a person’s body. Fat has to get stored as fat but excess simple carbohydrates like sugar or refined foods too get easily converted to fat and are stored as fat tissue in the body.
Body Weight: Obese people have more than 30% of their weight as fat tissue. On the other hand, an underweight person might have less than 5% overall body fat.
I hope this gives you a small insight into what are the avoidable as well as unavoidable causes of high-fat percentage.