These include age, muscle-fat ratio, height, sex, and body fat distribution, or body shape.
Having excess weight can affect a person’s risk of developing a number of health conditions, including obesity, type 2 diabetes, high blood pressure, and cardiovascular problems.
Not everyone who carries extra weight develops health problems. However, researchers believe that while these extra pounds might not currently impact a person’s health, a lack of management could lead to problems in the future.
Method 1: Body mass index (BMI)
BMI takes into account both height and weight but not body composition.
Body mass index (BMI) is a common tool for deciding whether a person has an appropriate body weight. It measures a person’s weight in relation to their height.
- A BMI of less than 18.5 means that a person is underweight.
- A BMI of between 18.5 and 24.9 is ideal.
- A BMI of between 25 and 29.9 is overweight.
- A BMI over 30 indicates obesity.
Weight and height guide chart
The following weight and height chart uses BMI tables to determine how much a person’s weight should be for their height.
|91 to 115 lbs.||119 to 138 lbs.||143 to 186 lbs.||191 to 258 lbs.|
|94 to 119 lbs.||124 to 143 lbs.||148 to 193 lbs.||198 to 267 lbs.|
|97 to 123 lbs.||128 to 148 lbs.||153 to 199 lbs.||204 to 276 lbs.|
|100 to 127 lbs.||132 to 153 lbs.||158 to 206 lbs.||211 to 285 lbs.|
|104 to 131 lbs.||136 to 158 lbs.||164 to 213 lbs.||218 to 295 lbs.|
|107 to 135 lbs.||141 to 163 lbs.||169 to 220 lbs.||225 to 304 lbs.|
|110 to 140 lbs.||145 to 169 lbs.||174 to 227 lbs.||232 to 314 lbs.|
|114 to 144 lbs.||150 to 174 lbs.||180 to 234 lbs.||240 to 324 lbs.|
|118 to 148 lbs.||155 to 179 lbs.||186 to 241 lbs.||247 to 334 lbs.|
|121 to 153 lbs.||159 to 185 lbs.||191 to 249 lbs.||255 to 344 lbs.|
|125 to 158 lbs.||164 to 190 lbs.||197 to 256 lbs.||262 to 354 lbs.|
|128 to 162 lbs.||169 to 196 lbs.||203 to 263 lbs.||270 to 365 lbs.|
|132 to 167 lbs.||174 to 202 lbs.||209 to 271 lbs.||278 to 376 lbs.|
|136 to 172 lbs.||179 to 208 lbs.||215 to 279 lbs.||286 to 386 lbs.|
|140 to 177 lbs.||184 to 213 lbs.||221 to 287 lbs.||294 to 397 lbs.|
|144 to 182 lbs.||189 to 219 lbs.||227 to 295 lbs.||302 to 408 lbs.|
|148 to 186 lbs.||194 to 225 lbs.||233 to 303 lbs.||311 to 420 lbs.|
|152 to 192 lbs.||200 to 232 lbs.||240 to 311 lbs.||319 to 431 lbs.|
|156 to 197 lbs.||205 to 238 lbs.||246 to 320 lbs.||328 to 443 lbs.|
|BMI||19 to 24||25 to 29||30 to 39||40 to 54|
What is the problem with BMI?
BMI is a very simple measurement. While it takes height into consideration, it does not account for factors such as:
- waist or hip measurements
- proportion or distribution of fat
- proportion of muscle mass
These, too, can have an impact on health.
High-performance athletes, for example, tend to be very fit and have little body fat. They can have a high BMI because they have more muscle mass, but this does not mean they are overweight.
BMI can also offer a rough idea of whether or not a person’s weight is healthy, and it is useful for measuring trends in population studies.
However, it should not be the only measure for an individual to assess whether their weight is ideal or not.
Method 2: Waist-hip ratio (WHR)
Measuring the waist
A person’s waist-hip ratio (WHR) can give an idea about whether they have more abdominal fat than is healthy.
A person’s waist-hip measurement compares their waist size with that of their hips.
Research has shown that people who have more body fat around their middle are more likely to develop cardiovascular disease (CVD) and diabetes.
The higher the waist measurement in proportion to the hips, the greater the risk.
For this reason, the waist-hip ratio (WHR) is a useful tool for calculating whether a person has a healthy weight and size.
Measure your waist-hip ratio
- Measure around the waist in the narrowest part, usually just above the belly button.
- Divide this measurement by the measurement around your hip at its widest part.
If a person’s waist is 28 inches and their hips are 36 inches, they will divide 28 by 36. This will give them 0.77.
Evidence suggests that WHR can impact the risk of CVD as follows:
- Below 0.9: The risk of cardiovascular health problems is low.
- From 0.9 to 0.99: The risk is moderate.
- At 1.0 or over: The risk is high.
- Below 0.8: The risk is low.
- From 0.8 to 0.89: The risk is moderate.
- At 0.9 or above: The risk is high.
However, these figures can vary, depending on the source and the population to which they apply.
WHR may be a better predictor of heart attacks and other health risks than BMI, which does not take fat distribution into consideration.
However, WHR does not accurately measure a person’s total body fat percentage, or their muscle-to-fat ratio.
Why is the hip-waist ratio important?
Method 3: Waist-to-height ratio
Waist-to-height ratio (WtHR) is another tool that might predict the risk of heart disease, diabetes, and overall mortality more effectively than BMI.
A person whose waist measurement is less than half their height has a lower risk of a number of life-threatening health complications.
Measure your waist-to-height ratio
A person’s height
A person’s height should be at least twice their waist measurement for a healthy WtHR.
To calculate the WtHR, a person should divide their waist size by their height. If the answer is 0.5 or less, the chances are that they have a healthy weight.
A woman who is 5 feet and 4 inches tall (163 cm), should have a waist measurement below 32 inches (81 cm).
A man who is 6 feet or 183 centimeters (cm) tall, should have a waist measurement below 36 inches or 91 cm.
These measurements will give a WtHR of just under 0.5.
Measurements that take waist size into account can be good indicators of a person’s health risks because fat that collects around the middle can be harmful for the heart, kidneys, and liver.
The Centers for Disease Control and Prevention (CDC) note that a man with a waist size of 40 inches or above, or a woman with a waist size of 35 inches or above has a higher risk than other people of:
- type 2 diabetes
- high blood pressure
- coronary artery disease
This does not, however, take a person’s height or hip size into consideration.
Method 4: Body fat percentage
Body fat percentage is the weight of a person’s fat divided by their total weight.
Total body fat includes essential and storage fat.
Essential fat: A person needs essential fat to survive. It plays a role in a wide range of bodily functions. For men, it is healthy to have 2 to 4 percent of their body composition as essential fat. For women, the figure is 10 to 13 percent.
Storage fat: Fatty tissue protects the internal organs in the chest and abdomen, and the body can use it if necessary for energy.
Apart from the approximate guidelines for men and women, the ideal total fat percentage can depend on a person’s body type or activity level.
ACE recommend the following percentages:
Activity level Male body type Female body type
Athletes 6–13% 14–20%
Fit non-athletes 14–17% 21–24%
Acceptable 18–25% 25–31%
Overweight 26–37% 32–41%
Obesity 38% or more 42% or more
A high proportion of body fat can indicate a greater risk of:
- heart disease
- high blood pressure
Calculating body fat percentage may be a good way to measure a person’s fitness level because it reflects the person’s body composition. BMI, in contrast, does not distinguish between fat and muscle mass.
How to measure body fat
Calipers measure body fat
Calipers measure body fat. The result can give an indication of whether a person is likely to have certain health risks.
The most common ways of measuring body fat percentage is to use a skinfold measurement, which uses special calipers to pinch the skin.
The health professional will measure tissue on the thigh, abdomen, chest (for men) or upper arm (for women). The techniques provide an accurate reading within around 3.5 percent, according to ACE.
Other techniques include:
- hydrostatic body fat measuring, or “underwater weighing”
- air densitometry, which measures air displacement
- dual energy X-ray absorptiometry (DXA)
- ï bioelectrical impedance analysis
None of these can give a 100-percent accurate reading, but the estimates are close enough to give a reasonable assessment.
Many gyms and doctor’s offices have devices for measuring a person’s body fat percentage.