The quest to lose body fat remains a popular google search and a common reason for people hiring nutritionists, health coaches and personal trainers. Common reasons for this desire to “optimise” body fat levels may be due to health concerns, alongside aesthetics and athletic performance. However, whilst too much body fat may pose a health risk, so can too little!
This article provides an overview of the role of body fat, whether there are ideal ranges of body fat, how they differ between males and females, the health implications of body fat levels that are too high or too low and our recommended body fat targets based upon the scientific data out there and clinical experience in this area.
Many become so consumed with the mission to reduce body fat that they fail to appreciate the important and vital role that body fat has. It provides a crucial store of energy reserves for metabolic fuel; it protects and cushions our organs and it keeps us warm!
Total body fat can be split into two categories: essential fat and storage fat.
Essential fat is the amount of fat that is necessary in order to stay alive, as well as for other important functions such as reproductive health. Essential fat is present in organs, bone marrow, nerve cells, and the brain. On average, the amount of essential fat for a female is 10-13% and for a male is 2-5%.
Storage fat is deposited just under the skin and otherwise known as subcutaneous fat. Again, subcutaneous fat is necessary for protection against infection, the cushioning of organs and to maintain a healthy body fat percentage.
In addition, we also have visceral fat. Visceral fat is a type of body fat stored within the abdominal cavity, located near several vital organs. Unlike subcutaneous fat, which is found just under the skin, visceral fat is more deeply embedded and can significantly affect health. High levels of visceral fat are linked to various health risks, such as cardiovascular disease, type 2 diabetes, inflammation, and metabolic syndromes.
Classifications of percentage body fat
Whilst research clearly shows that increased body fat is associated with a host of chronic diseases and increased mortality, too low body fat is also associated with severe health risks and is dangerous. So, what is too high or too low? Well, it all depends on you! Your sex, race, and age.
Two key trends are that, in general, men have a lower body fat percentage than women and body fat percentage increases with age. Below are target body fat ranges presented in research studies. Note that there are variations in the method of assessment.
There is no one voice for optimal and average body fat percentage ranges. However, we have provided some guidelines from institutes and research studies below, as well as our own optimal body fat targets.
American council of Exercise ACE ranges (calliper-based measurements)
Whilst we have used skinfold callipers in clinical practice, we find the equations associated to calliper use do not provide an accurate measurement of body composition when compared to more gold standard measurements. Not to mention, the invasive nature of taking skinfold measurements for many clients.
For this reason, we use the SECA mBCA 525 device in clinical practice to establish accurate body composition readings. On request, skinfold calliper measurements can also be taken as well, particularly if wanting to track subcutaneous fat changes from different areas of the body.
For more information and to request a body composition test at our clinic in London, please go to our body composition testing page.
American College of Sports Medicine (ACSM) ranges
These ranges are based upon a sample size of 18,507 individuals
Males
Females
Proposal of normative table for body fat percentages through bioimpedanciometry – Journal of Exercise Rehabilitation
Is there an ideal body fat percentage?
The charts indicate the differing ranges of body fat percentages by age group, race and sex. A good body fat percentage for a female, might be around 20-30%, and for a male, 10-20%, however for athletes, this is likely to be lower, potentially 15-20% and 6-10% for females and males respectively.
On average, above 35% for females, and 25% for males, appears to be associated with increased risk of chronic disease and mortality. Increased risk of medical complications and health deterioration also appear to be associated with body fat percentages below 15% for females and below 6% for males.
It is important to note that the health impacts of too low or too high body fat do not tend to be immediate and therefore it is possible to ignore the reality that these increased health risks are present.
Depending on the individual, it may take some time for reduced health to manifest, and it also may not be possible to realise this unless you have objective markers – for example, blood tests. Additionally, the ideal body fat percentage will be unique to you – for instance, one female may stop menstruating at a lower body fat percentage than another.
Another factor to consider is that of water and muscle levels. When muscle and water increase, this will decrease the body fat percentage. It is incredibly important to also look at the total fat weight and not just body fat percentage when assessing one’s body fat levels. We also look at ones fat mass index, which is your body levels in kilograms divided by your height squared. See a section of our body composition assessment report below.
Body fat percentage should always be assessed in accordance with other body composition measurements and health status/symptoms to determine what is high, normal or low for that individual. This is why we have a team of trained Nutritionists that carry out these tests, so they can provide context to your given situation.
We can carry out these body composition assessments at our clinics in London and Hertfordshire.
Health effects of too low body fat
Too low body fat, and for a long period of time, may have a devastating effect on your health. Obviously, the degree of how low body fat is and for the duration, impact symptoms.
Exercise performance and recovery will be impaired by too low body fat, with excessive cramping, fatigue and higher risk of injury. Nutrient deficiencies, electrolyte imbalances and reduced energy availability ultimately affect every organ in the body.
Other manifestations may be, hair loss, constipation, dry skin, mood swings, poor concentration and low blood pressure. Non-essential functions suffer first, to preserve life – so levels of different hormones become altered, sex hormones drop, resulting in loss of libido to loss of menstrual cycle. Immune function will also be impaired and bone density is reduced, with increased risk of fractures to long-term development of osteoporosis.
Ultimately every organ in the body is affected, with impairment to the endocrine, cardiovascular, reproductive, skeletal, gastrointestinal and renal system. Severely too low body fat levels can result in death and prolonged durations of too low body fat will result in premature death.
Health effects of too high body fat
Too low body fat, and for a long period of time, may have a devastating effect on your health. Obviously, the degree of how low body fat is and for the duration, impact symptoms.
Exercise performance and recovery will be impaired by too low body fat, with excessive cramping, fatigue and higher risk of injury. Nutrient deficiencies, electrolyte imbalances and reduced energy availability ultimately affect every organ in the body.
Other manifestations may be, hair loss, constipation, dry skin, mood swings, poor concentration and low blood pressure. Non-essential functions suffer first, to preserve life – so levels of different hormones become altered, sex hormones drop, resulting in loss of libido to loss of menstrual cycle. Immune function will also be impaired and bone density is reduced, with increased risk of fractures to long-term development of osteoporosis.
Ultimately every organ in the body is affected, with impairment to the endocrine, cardiovascular, reproductive, skeletal, gastrointestinal and renal system. Severely too low body fat levels can result in death and prolonged durations of too low body fat will result in premature death.
How to work out what is your ideal body fat percentage?
Consider feedback from your body to inform decisions:
If you have any potential signs that your body fat is too low, begin taking action to change this or enlist some support. Our Nutritionists are on hand to support you with your goals.
A lack of calories consumed on a regular basis in relation to energy expenditure is common in more athletic populations. However, this can be overcome with appropriate support, nutrition, and training management.
Consider body weight and composition measurements:
If you have had feedback from your doctor that you may be under or overweight, it might be worth further investigating this. The use a body composition assessment that looks at fat mass in kilograms, body fat percentage, your fat mass index, visceral fat, muscle levels and water levels to give us a clear picture. This also allows us to set appropriate body composition goals for our clients and guide their nutrition and training accordingly.
Consider how balanced your nutrition, training and lifestyle:
If you never work out, then consider introducing more movement and training in your lifestyle – whether that’s aerobic, resistance or a combination of both.
Have a think about your diet – how do you approach it and does it provide you with the sustained energy your require for your lifestyle? Equally, if you are always doing HIIT (high intensity training) workouts and skimping on your energy dense foods, maybe change up of your HIIT for something of lower intensity and introduce additional calories.
There are so many ways to find appropriate energy balance to optimise body composition. Its really about understanding your demands, establishing your preferences and then formulating a realistic plan of action.
Consider what is “healthy” rather than focusing solely on appearance:
Whilst there is nothing wrong with valuing physical appearance and aesthetics, balancing it with what makes us feel good on the inside and is best for us in the medium and long term and overall health and well-being is also important.
Consider what is right for you:
Whilst average body fat percentages can be helpful information for one to be aware of, remember that you are unique and to ultimately follow what is right for you. Your ideal body fat percentage might well be slightly different to your best friends and that’s totally fine.
Try to avoid chasing numbers for numbers sake! We have seen many clients come unstuck because they have a fixed idea on what their body weight/body fat percentage should be, and that number can unfortunately become a number that determines mood or perception of success.
Combining body composition assessments, blood testing, symptoms and physical and mental health status is a far more appropriate when determining where someone is on their body composition journey.
A few words on Body Mass Index (BMI)
Whilst it is assumed that BMI is strongly positively associated with body fat percentage, studies indicate that this relationship may not be so strong (Meeuwsen et al. 2010).
Research indicates that there is only a weak association at a lower BMI, and that the association is not strong within the desirable range and is greatly affected by a variety of factors such as age (Meeuwsen et al. 2010). There may be a high degree of variability in body fat percentage within the same BMI values, which is especially evident when BMIs between different ethnicities are compared (Ramel et al. 2013).
Research indicates that health and risk of death increase at a lower BMI and at a higher BMI (Lee et al. 2018). There is an increased mortality risk at a lower BMI, which may be due to either a too low body fat percentage or low lean body mass. There is also an increased mortality risk at the BMI range of 25-29.9, and a more rapid increase in mortality risk over a BMI of 30 (Lee et al. 2018).
As BMI is merely a height and weight-based measurement it should be used with caution. For example an individual weighing 85kg and 175cm tall with 10% body fat and significant muscle mass has the same BMI as another individual of the weight and height but with low muscle mass and 35% body fat.
Key take-aways:
Body fat is essential for health and well-being: having both too low body fat levels and too high body fat levels are associated with severe health complications. On average, above 35% for females, and 25% for males, appears to be associated with increased risk of chronic disease and mortality. Increased risk of medical complications and health deterioration also appear to be associated with body fat percentages below 15% for females and below 6% for males.
Target optimal body fat percentages for males and females: A goal of 10-20% for males and between 20-30% for females I believe to be a very good range. For athletic populations this is likely to be lower, potentially 6-10% for males and 16-20% for females. however, this really does depend on the sport an of course your muscle and water levels.
Accurately assess your body composition in London & Hertfordshire
to learn more about the body composition assessment we use as well as rates and to book an appointment, please visit our body composition testing page.
References
- Lee et al. (2018). Predicted lean body mass, fat mass, and all cause and cause specific mortality in men: prospective US cohort study.
- Meeuwsen et al. (2010). The relationship between BMI and percent body fat, measured by bioelectrical impedence, in a large adult sample is curvilinear and influenced by age and sex.
- Ramel et al. (2013). Relationship between BMI and body fatness in three European countries.
- Borga et al. (2018). Advanced body composition assessment: from body mass index to body composition profiling.
