We often think of body fat in negative terms, yet fat is essential to maintain normal body functioning. Body fat is important to us for several reasons. It transports the fat-soluble vitamins A, D, E and K around the body. These fat-soluble vitamins are essential to maintaining body functioning. Fat is a source of stored energy to be used for daily activities and to maintain body functioning. It also helps to conserve heat.
Your body stores a certain amount of fat to be used for energy. If these stores become depleted, the body’s response is to turn a large proportion of the food consumed during your next meal into fat. This fat is stored so your body’s fat stores do not become that depleted again. This is a key reason why you should eat regularly throughout the day.
In addition, fat supplies essential nutrients including fat-soluble vitamins and essential fatty acids around the body. It cushions and protects our internal organs. Without this protection, the body’s internal organs would be exposed to damage.
Why body fat percentages are used?
Body fat percentage is used to assess health over body weight or body mass index (BMI) as it is more specific to each individual.
health conditions that are associated with having too much body fat are widely known and include type 2 diabetes, hypertension, osteoarthritis and some cancers
How body fat is measured?
The most common ways of measuring body fat percentage are:
Bioelectrical impedance analysis (BIA): this uses a low voltage electric current that goes up one leg and down the other. As water conducts electricity, you should aim to be of a similar hydration level each time you are measured. If the test has been carried out correctly, the margin for error is +/-3%. If carried out incorrectly, the accuracy can vary +/-10%. Scales that measure body fat are widely available.
Skin-fold testing: this uses calipers to measure total body fat and is carried out by a trained professional. When done correctly, this method is more accurate than BIA testing.
What is a healthy body fat percentage?
Ideal body fat percentages vary considerably for men and women by age; the table below summarises the ideal ranges for each gender at various stages of life. Some variation also exists between different ethnic groups, these figures are however based on a Caucasian population only.
Age Male Female
10-30 10-18% 20-25%
31-40 13-19% 21-27%
41-50 14-20% 22-28%
51-60 16-20% 22-30%
60+ 17-21% 22-31%
What if you have too little or too much body fat?
Too little body fat can lead to the loss of reproductive functions, skeletal and cardiovascular problems, hormonal disturbances and abnormalities of the immune system.
The health conditions that are associated with having too much body fat are widely known and include an increased risk of:
- hypertension (high blood pressure)
- type 2 diabetes
- some cancers
- hypercholestrolemia (high cholesterol)
- heart disease
How body fat can be reduced?
Being physically active and eating a healthy, balanced diet can make a huge difference. If you are at all concerned about your body fat percentage, speak to your GP. If your doctor identifies a problem, a calorie controlled diet and exercise programme may be prescribed. As there are many health risks associated with having a body fat percentage that is either too high or too low, it is important to act now and start making healthy changes.