What is body fat percentage? Is the lower the body fat, the better it would be? Men and women should have different levels of body fat percentage? What would happened if body fat parentage is too low?
Written by: Ms. Sylvia Lam, Full Member of Hong Kong Dietitians Association
Accredited Practising Dietitian (DAA Australia)
Our body is mainly made up of two different body masses which include fat free mass and fat mass.
1. Fat free mass includes bone, water, muscle, organs and other body tissues. It may also be called lean body mass. These tissues are metabolically active and help burn energy to maintain bodily functions.
2. Fat mass can exist in muscle tissue, under the skin (i.e. subcutaneous fat) and around the organs (i.e. visceral fat). Our body needs essential fat in order to keep our body going including those use for organ protection, energy reserve and hormone production.
There are many ways to measure body masses, such as Bioelectrical Impedance Analyzer – BIA (which often called “body fat scale”), DEXA scan and skinfold measurements. DEXA scan and skinfold measurements need highly skilled people and equipment to perform which are more complicated. While BIA uses a small electric current going through the body, so that fat, water and lean body mass impede the electric current difference to provide us the results. There are now many home-use “body fat scales” which are easily operated facilitating daily monitoring of body weight and also body masses.
According to The American Council on Exercise (ACE), different people should have different level of body fat %:
|Classification||Women (% fat)||Men (% fat)|
|Obese||32 or above||25 or above|
For athletes or people who participate in elite sports, lower body fat and higher lean body mass would enhance sports performance, especially to sports which require speed. However, if female has too low body fat percentage, it might affect normal body functions. For example, it might lead to hormonal imbalance resulting in amenorrhea, infertility, anemia, comprised immunity, disordered eating and risk of bone fracture. Long term low body fat percentage in female would increase risk of osteoporosis and mental disorders. Many females who participate in dancing, gymnastics and ice-skating sports etc. are more prone to the above health conditions. Contrastingly, adults who have high body fat percentage might lead to obesity and other obesity-related diseases such as diabetes, heart diseases, cancer, joint problems and gout etc.
To people who are 60 years old or above, their body fat percentage should be slightly higher than regular adults. As elderly easily gets sick leading to poor appetite, the fat reserve can help provide extra calories while they are not eating too well. The fat reserve in this situation can lessen drastic weight loss which influences the resistance of the disease and speed of recovery. Besides, elderly, especially those who has less lean body mass, is at risk of fall. Extra body fat can help protect elderly from bone fracture when fall unfortunately occurs. Nevertheless, our skin will get thinner and metabolism will slowly reduce when we age, body fat can also help keep our body warm, subsequently reduces the chance of illness at an older age.
In summary, body fat percentage should not be too low or too high. In order to maintain good health, one should achieve adequate levels of fat free mass and fat mass according to gender, age and level of exercise. One should also take into consideration their body mass index and waist circumference. In addition to purchasing a “body fat scale” for home use, one can also consult a Registered Dietitian and a qualified physical trainer to help perform a detailed assessment. If needed, they could also provide you with suitable eating and exercise recommendations, so to achieve an optimal body composition.
Health information reference provided by Senior Registered Nutritionist Ms. Sylvia Lam.