Method 2: Waist-hip ratio (WHR)
A waist-hip measurement is the ratio of the circumference of your waist to that of your hips. You measure the smallest circumference of your waist, usually just above your belly button, and divide that total by the circumference of your hip at its widest part.
If a woman's waist is 28 inches and her hips are 36 inches, her WHR is 28 divided by 36 = 0.77. Below is a breakdown of WHR linked to risk of cardiovascular health problems.
- Less than 0.9 - low risk of cardiovascular health problems
- 0.9 to 0.99 - moderate risk of cardiovascular health problems
- 1 or over - high risk of cardiovascular problems
- Less than 0.8 - low risk of cardiovascular health problems
- 0.8 to 0.89 - moderate risk of cardiovascular health problems
- 0.9 or over - high risk of cardiovascular problems
The WHR of a person is commonly said to be a much better indicator of whether their body weight is ideal and what their risks of developing serious health conditions are, compared to BMI. Various studies have shown that people with apple-shaped bodies - who have larger WHRs - have higher health risks compared to people with pear-shaped bodies - who have lower WHRs. An apple-shaped person will have more fat accumulating on the waist, while a pear-shaped person has the fat accumulating on the hips.
A woman with a WHR of less than 0.8 is generally healthier and more fertile than females with higher WHRs. They are less likely to develop diabetes, most cancers, or cardiovascular disorders. Similarly, men with a WHR no more than 9 are generally healthier and more fertile than men with higher WHRs, and less likely to develop serious conditions or diseases.
Studies indicate that if WHR were to replace BMI as a predictor of heart attack worldwide, figures would include many more people.
What is the problem with WHR?
WHR does not accurately measure a person's total body fat percentage, or their muscle-to-fat ratio. However, it is a better predictor of ideal weight and health risks than BMI.
Method 3: Waist-to-height ratio
In a study in 2012, Dr Margaret Ashwell, who used to be science director of the British Nutrition Foundation, and team found that waist-to-height ratio was better at predicting future heart disease and diabetes risk than BMI.
Dr. Ashwell presented her team's findings at the 19th Congress on Obesity in Lyon, France, on 12th May, 2012.
Dr. Ashwell said, in an interview with The Daily Telegraph, a leading UK newspaper:
"Keeping your waist circumference to less than half your height can help increase life expectancy for every person in the world."
- A man 6ft (72 inches, 183 cm) tall, should keep his waist measurement below 36 inches (91 cm)
- A woman 5ft 4 inches, i.e. 64 inches (163 cm) tall, should keep her waist measurement below 32 inches (81 cm)
Dr. Ashwell suggests waist-to-height ratio (WHtR) should be used as a screening tool.
Her team found that after analyzing several studies involving approximately 300,000 people, WHtR was better at predicting heart attacks, stroked, diabetes, and hypertension risk compared to BMI.
Ashwell explained that BMI does not take into account fat distribution around the body. The accumulation of abdominal fat (visceral fat) may be harmful for the heart, kidneys and liver, while fat build-up around the hips and bottom is less hazardous to health.
The researchers added that WHtR is much simpler for people to work out:
“Keep your waist circumference to less than half your height"
How do you measure your waist?
The World Health Organization suggests that you measure your waist mid-way between the lower rip and the iliac crest (the top of the pelvic bone at the hip) ("Waist To Height Ratio Better Than BMI". Catharine Paddock PhD. Medical News Today. 13 May 2012)
Method 4: Body fat percentage
Your body fat percentage is the weight of your fat divided by your total weight. The result indicates your essential fat as well as storage fat.
- Essential fat - this is the amount of fat we need to survive. Women require a higher percentage than men. Essential fat is 2%-5% in men, and 10%-13% in women.
- Storage fat - this consists of fat accumulation in adipose tissue, some of which protects our internal organs in the chest and abdomen.
- Total body fat percentage - this is essential fat plus storage fat.
The American Council on Exercise recommends the percentages below:
- Women 10-12%
- Men 2-4%
The total fat percentages are divided up by body type:
- Men 6-13%
- Women 14-20%
Non-athletes classed as fit
- Men 14-17%%
- Women 21-24
- Men 18-25%
- Women 25-31%
- Men 26-37%
- Women 32-41%
- Men 38% or more
- Women 42% or more
Many experts say that calculating people's body fat percentage is the best way to gauge their fitness level because it is the only measurement that includes the body's true composition. Any male whose body fat percentage is over 25% or female over 31% is either overweight or possibly obese.
Body fat percentage would not make the couch potato seem fitter than the 100 meter Olympic champion - as was the case with BMI.
There are various ways of calculating a person's body fat percentage. None of them can give a 100% accurate figure, but the estimates are accepted as fairly close. Examples include near-infrared interactance, dual energy X-ray absorptiometry, and bioelectrical impedance analysis.
Many gyms and doctor's practices have devices that can tell you what your body fat percentage is.
Conclusion about calculating how much you should weigh
This article has briefly explained four ways to help you find out whether your weight is ideal, and what your target should be if it is not. You can work out your BMI (body mass index), WHR (waist-hip ratio), WHtR (waist-height ratio) or Body Fat Percentage.
BMI, WHR and WHtR can be done easily in your home. WHR and WHtR are more accurate than BMI. However, BMI is a useful indicator if you are an "average" person - not an Olympic athlete or a dedicated weight trainer.
If you embark on a weight loss regime that includes exercise and diet, bear in mind that the exercise will probably increase your muscle mass, which may increase your weight, even though your waist may shrink. Muscle weighs more than fat.
It might be better to aim for target waist, hips and chest measurements. A Waist-hip ratio goal is also possible. If you feel really dedicated, check your Body Fat Percentage; if you are not happy with the reading, discuss a realistic target with a nutritionist, sports scientist, or personal trainer and go for it!
In this video by What Matters Nutrition, David Brewer, a registered dietician, takes a look at the question of ideal weight, discussing many of the points raised above.