Your Weight Speaks Your Health
Not too distant in the past people used to interact in person with their neighbors and friends. In fact, if you see some older houses in the US constructed around 1960’s promoted interaction having a big lawn on the front where children played, and adults chit chatted. Things changed drastically around 2000 with new technology and gadgets, and the personal interaction slowly changed into virtual interaction. This created an environment where you are mostly inside your room un-oblivious of the fresh breeze, beautiful sunshine, and natural beauty outside. I even know many people who won’t let sunrays come into their room with pulled curtain all day long. Things have changed! Looks like there is no looking back!
These changed habits and technological advances have changed our body chemistry albeit unknowingly. Whenever I meet someone in a gathering or party people will come to me and comment, “I gain weight even if I smell the food, let alone eating”. While we are in corona virus pandemic situation since 2019, being overweight is no less than this pandemic. Obesity is a crisis in most part of developed world! But unlike corona virus, you can control your body by understanding few fundamental things rather than trying various fad diets, weight loss programs and pills only to realize that they never work in the long run! Because fundamentals must be right. Science is science, it is data driven! So, believe in science to keep yourself healthy and happy at any age!
The purpose of this article is for you to understand few fundamentals so you can take some measurements in the comfort of your home and keep a check on your body that generally tells a lot about your health.
I will discuss three things here to start with:
· Body Mass Index (BMI)
· Body Fat measurement
· Correlation and interplay of fat and muscle
BMI (Body Mass Index)
Whether you feel perfectly healthy or have health concerns, the first step that you should do is to know your Body Mass Index (BMI). The index has been developed to quickly find out if a person has normal weight or is overweight or underweight. In fact, this is based on large clinical trials conducted over several years in various parts of the world including leading role by US. The scale is good for people (any gender) ages 2 years to 60 plus.
BMI can be easily calculated by the following formula using metric system which uses kilograms and meters:
· Formula: weight (kg) / [height (m)]2
Weight= 81.6 kilogram (kg)
Height= 168 centimeter (cm)= 1.68 meter squared = 2.82.
Note: Divide height in centimeter (cm) by 100 to get height in meter (m). Then, divide weight in kg by height in meter
· BMI= 81.6/2.82= 29
You can also calculate BMI using UK pound (lb.) for weight and inches (in) for height. Note: Above metric weight and height converted into pound for this example to show the same computed value.
· Formula: weight (lb.) / [height (in)]2 x 703
Example: weight= 180 lb.; height in inches= 66 in squared= 4356 inches
BMI= (180*4356)/703
· BMI= 29
While calculating using your own head is good for your brain, you can use the free US Government National Institute of Health calculator to compute your BMI.
Interpreting BMI value for adults
Table below gives BMI ranges that relates grossly to your health
You can consult National Institute of Health (NIH) chart that breaks down BMI at various heights in inches and weight in pounds. Where do you fit in this chart? Are you healthy? If not, it’s time to some action!
Explanation is provided below for various BMI category:
Underweight
You think overweight is a big problem think again! Trying to gain weight for “underweight” category people is as difficult as it is for “overweight” category to shed few pounds! So, people in “underweight” category should be interpreted cautiously. For example, underweight the so-called skinny people that otherwise may be very healthy even with lower BMI. It is important to know the weight history of the person since an early age of their growth period. Question to ask: What was the weight at age 18, 25, and 30? Did the weight decrease rapidly? A rapid weight loss may indicate some other underlying problems!
A 50-year person who was 5 feet 6 inches in height and weighed 113lb came to me asking how to put on more weight. After inquiring about his weight history, it was clear that he was in the lower BMI weight range (underweight) all his life. His blood chemistry including lipid panels and blood glucose was in normal range. He didn’t seem to have any underlying issues. I believe this is fine given his unremarkable good health.
Normal
If you are in this range, keep up the good work. Monitor your cholesterol and HDL (good cholesterol), triglycerides and blood sugar level and adjust your diet to be in this healthy range.
Obese
If you are in the BMI range of “obese”, this may lead to several risks such as listed below:
Cardiovascular Risk
High blood pressure (hypertension)
High LDL cholesterol ("bad" cholesterol)
Low HDL cholesterol ("good" cholesterol)
High triglycerides
Diabetes (high blood sugar) Type 2
Extreme Obesity
A BMI of 30 and above will put you in extreme obesity range that must be avoided. These people may already have several conditions listed above under Obese and many more.
Interpreting BMI value for children/ teens: 2 to less than 20 years old
BMI is calculated the same way however it is interpreted as age percentile for children/ teens. You can use this BMI calculator for teens and children by Center for Disease Control (CDC), a government organization, to know the BMI-for-age-percentile for your child.
BMI-for-age-percentile for children and teens
But let us understand percentile part first: BMI-for-age percentile shows how your child’s weight compares to that of other children of the same age and sex. For example, a BMI-for-age percentile of 65 means that the child’s weight is greater than that of 65% of other children of the same age and sex.
Let’s take some examples:
Enter in calculator the following for a boy:
· Age: 12 year, 5 months
· Weight: 80 pounds
· Height: 5 feet or 6 inches
The calculated BMI for the boy is 15.6. This places the BMI-for-age at the 9th percentile for this boy. This falls in the BMI-age percentile category of healthy weight shown in the table below. In other words, this boy weight is greater than that of 9% of other boys of the same age.
Enter in calculator the following for a girl:
· Age: 12 year, 5 months
· Weight: 150 pounds
· Height: 5 feet or 6 inches
The calculated BMI for this girl is 24.2. This places the BMI-for-age at the 92nd percentile for this girl. This falls in the BMI-age percentile category of overweight. In other words, this girl weight is greater than that of 92% of other girls of the same age.
Note that just the BMI (not percentile) for children generally follows BMI values of adults but since children are in growth mode, the percentile gives a better value for understanding your child’s growth.
Is BMI a good indicator of health status
In general, yes! Please note that BMI is a screening tool that must be used in combination with other tools to come to a definitive conclusion. BMI is variable depending on race, ethnicity and region where you live. For example, for the same weight and height, Blacks may have less fat and more muscle mass contrary to Southeast Asians with more fat and less muscle mass. Obesity could be hereditary. In conclusion, myriads of factors may influence a person’s BMI including environment and living conditions.
Body fat and muscles interplay
Both, fat and muscles are extremely important to the body. Body fat is critical for health and longevity. Fat surrounds and cushions many internal such as kidney, liver. It insulates us from cold and it is a great source of energy and may keep a person alive during starvation. Muscles make the muscular system composed of specialized cells called muscle fibers. Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement. Nearly all movement in the body is the result of muscle contraction.
Most people easily get fat but not muscular with sedentary life. It is well known that, in general, people lose 10% muscle every 10-year starting age 40 thereby increasing their % fat and decreasing muscle mass. This could be prevented or slowed down by regular weight-bearing exercises.
This brings us to the topic of how to measure and evaluate your body fat at home to take control of your own health.
Measurement of Body Fat
The below Table is adopted from American Council on the Exercise (ACE) provides a good starting point for people who are serious to maintain their health by controlling body fat percentage.
The below Table shows body fat % by age group that could be more useful if you are adjusting for age. The table is adopted from the fitness assessment manual of American College of Sports Medicine.
Waist-Hip Ratio measurement
One method to quickly measure fat distribution is Waist-Hip Ratio (WHR). You can measure it at home using a tailor’s measuring tape. Wrap the measuring tape around your stomach just above the belly button and see how much it is. This is called circumference. Next, slide the tape around the middle of your hip and move it up or down to take the measurement that have the highest value.
Divide waist circumference by hip circumference to get the ratio. The following table is based on findings by World Health Organization (WHO) for developing various health risks from Low to high based on your body fat levels. Some of these risks are:
· Cardiovascular
· Diabetes
· Obesity and related problems
People whose stomach protrude out significantly, but the hip is almost flat are at higher risk that the people other way around. In such situations, the ratio is greater than 1.
Waist-to-Height Ratio (WHtR) measurement
Divide waist circumference by your height to get the ratio. See example below:
· Waist= 45 inches
· Height= 55
· WtHR= 45/66= .68
A WHtR cutoff of 0.5 is generally accepted as a universal cutoff for central obesity in children aged ≥6 years as well as in adults per NCBI publication. The additional use of WHtR with BMI or WC also appears to be helpful for screening those with higher cardiometabolic risk. Most recent studies now include the WHtR as a major adiposity index, regarding it as a validated and universal index of central adiposity.
In the above example, a ratio of .68 is more indicative of fat accumulation in your torso area (trunk/ stomach area) around which important internal organs are located such as kidney, heart, liver etc.
Waist Circumference (WC)
While Ratio provides better correlation, just measuring only waist circumference provides good indication about your health status and pre-disposition to diseases. Per NIH US government publication, your waistline may be telling you that you have a higher risk of developing obesity-related conditions if you are:
A man whose waist circumference is more than 40 inches
A non-pregnant woman whose waist circumference is more than 35 inches
Skinfold measurement
About 50% of total body fat is present under the skin. While fat is essential for survival, too much fat in the body leads to various diseases including diabetes, hypertension, heart-related risks. Measuring skinfold at various locations on the body provides a good measurement of % body fat. Using a skinfold caliper, you can measure your % body fat at home. You can buy simple skinfold caliper online- prices may vary from $10 to $400.
It is simple to measure. Fold the skin of the selected areas using your left-hand thumb and index finger while putting the caliper pads on the folded skin with right hand to take the measurements. ACE has provided good details on how to take the measurement. It also provides a skinfold calculator where you can plug in your measurement numbers to get the % body fat.
Since men and women store fat differently in different regions of their bodies, the following are recommended sites for measurement:
Men:
· Chest (diagonal skinfold midway of underarm and nipple),
· Thigh (Vertical skinfold between hip and knee joint,
· Abdomen (vertical skinfold just above bellybutton)
Women:
· Triceps (Vertical skinfold back of the upper arm between shoulder and elbow)
· Thigh (same as described for men)
· Waist area (side skinfold just above hipbone)
Home bathroom weight Scale
Knowing your fat weight and lean weight in terms of body composition can provide a good parameter and objective as to where you want to be for % body fat in a year or so.
Most people in developed countries have bathroom scale in their homes. If you are interested, you can buy one that has features of measuring % body fat. Such scales use bioelectrical impedance by using small amount of electric current. Fat is not a good conductor of electricity, so more the fat in the body higher the electrical impedance. The impedance is converted to % body fat. After initial adjustment for some parameters such as age and height, all you must do is to stand on the scale. This gives a ballpark estimate of your % body fat; however, this method is not very accurate.
Other methods
There are other methods for % body fat measurement, but these are mostly used in clinics and gyms. DXA scan (dual-energy X-ray absorptiometry) uses low level X-ray energy to determine body fat and lean muscle.
Under water weighing called Hydrodensitometry uses water displacement to measure body fat percentage. Note that for the same volume, fat weighs less that muscle.
Above two methods require trained technician but give reasonably accurate analysis.
Key Takeaways
1. Use various methods to screen yourself at home to determine your health status. This is the first step toward your wellness
2. Measure BMI and % body fat by using two methods from below list:
a. Waist-Hip ratio
b. Waist-to-Height Ratio
c. Waist Circumference
d. Skinfold measurement
e. Home bathroom weight Scale
3. Maintain a journal and jot down your BMI and % body fat. Ask question, “Am I in healthy normal range?
4. If you are in healthy range, enjoy life and keep it doing whatever you are doing!
5. If you are not in healthy range, take charge of your body and health by implementing remedial actions leading to good health. This will be described in subsequent publications on this site.