Body Mass Index (BMI) uses both an individual’s weight and height in estimating the person’s level of fatness. For the majority of the population, using the BMI calculator is a fair enough gauge, a noninvasive method to perform, and a simple measurement to apply. A BMI that’s higher than 25 means you are overweight. When it is over 30, that indicates obesity. It’s what helps doctors evaluate a patient’s risk of developing diseases like hypertension, cardiovascular disease, certain cancers, and type 2 diabetes as quickly as possible. Although BMI can help within a clinical setting, it is certainly not infallible. As a matter of fact, it can under- or overestimate people’s fatness.
BMI, more often than not, can go wrong. It’s already known to flag the athletic and particularly muscular as obese or overweight incorrectly. Myriads of studies have been conducted which all have revealed that the metric misses another category of individuals: those that have fat in dangerous places of the body but are labeled as normal. They are the people who walk around thinking they are perfectly healthy even when they are at a higher risk of suffering from diabetes, heart disease, and even premature death.
Now that you know BMI is unreliable, you’d start questioning all its other limitations. Also, you’d wonder if a measurement that’s accurate exists. Before we talk to you about other means to determine your current health status, let’s first educate you on BMI and all the reasons why it can be misleading.
How Was the BMI Chart Developed?
Body mass index, as you already know, is the measure of your body fat based on your weight and height. It can apply to any individual, regardless of age, ethnicity, and gender. Once you reach adulthood, your BMI score should not change drastically.
The chart that’s used by authorities including the National Health Institute can be split into 4 categories:
- Normal Weight – A BMI score of 18.5 to 24.9
- Underweight – A BMI score that’s less than 18.5; Take note that there are experts who would claim that the number should be 19 or closer to it as an 18.5 BMI score is rarely a weight that is healthy for most adults;
- Overweight – A BMI score between 25 to 29.9
- Obesity – A BMI score of 30 or more
Based on the chart, an adult woman who’s 5 ft., 5 in tall should have a weight of 114 to 144 lbs. for her to be considered as “normal” or “healthy.” Weighing 150 to 174 lbs. would make the lady overweight. Above 180 lbs., and she’d be obese. Anything above 180 lbs. would be labeled as extreme obesity.
For an adult male who’s 6-ft tall, the normal range would be between 140 to 177 lbs. For him to be overweight, he should weigh anywhere between 184 to 213 lbs. To consider the man obese, he needs to be over 220 lbs. in weight.
When BMI was first developed, the original goal was to help adults achieve their “ideal weight.” In the 1940s, the ranges for ideal weight were determined by their height and body composition or body frame. A heavier ideal weight range was established for women who are large-framed compared to medium- or small-framed women.
Eventually, the ideal weight and height tables received criticism as they were methodically flawed. According to experts, they did not consider age or genetic difference, so they have since been abandoned in place of the use of the BMI chart.
According to researchers, since the 1970s, the BMI chart managed to replace all other means of measuring obesity even when it also received several criticisms. Research does not deny the fact that BMI scores provide a great recognition of people who have a weight problem in comparison to previous weight and height charting. But, one thing’s undeniable: it is inconsistently used by millions of patients and doctors alike.
History of BMI
Body mass index came into fruition as medical professionals, researchers, insurance companies, and the government needed a simple method in tracking health risks among the country’s population. In the early 1970s, Ancel Keys, a researcher, coined the term “BMI” in a paper that he published. In the study, Keys looked at more than 7,000 men from different countries. He then analyzed their subcutaneous fat thickness and adiposity-body density, which are both measurements of body weight. Using the index of weight-to-height which has been devised by Quetelet, Adolphe in 1832, Keys made BMI a simple and straightforward way to measure a person’s body weight relative to the individual’s height.
Problems with BMI and Reasons Why the Chart Misleads
While BMI can be helpful in the identification of weight gain in most of the world’s population, it is not an accurate or foolproof depiction of being obese or overweight for every person. In fact, even the National Health Institute pointed out that the chart has limits.
The reasons why doctors still take a person’s BMI score is because it’s quick and a gauge that is “good enough” when identifying a person’s risk for all the diseases tied to obesity. High blood pressure, heart diseases, high triglycerides, and diabetes are conditions or diseases that occur in individuals who have a high level of body fat. It is important to note that there still lots of debate over the causes of the diseases mentioned apart from excess body fat as health problems can also be due to the accumulation of poor lifestyle habits.
Some of the negative criticisms associated with BMI include:
- The BMI chart overestimates the body fat in professional athletes and people who have muscular builds – The biggest criticism of BMI is it does not consider the individual body composition of a person, as well as the ratio of fat-free mass to body fat. It also neglects other measurements including bone mass, frame size, and muscle mass. What’s more, BMI does not consider differences in gender nor take into account certain locations in the body for body fat (especially near the waist) which are more harmful compared to others (near the thighs).
Studies have shown that there are significant ethnic differences in terms of body composition. To be more specific, people of African or Asian descent are genetically smaller-framed compared to people of Native American or Hispanic descent. As for surveys, they’ve found that Hispanics and African-Americans have significantly higher BMI scores relative to their Caucasian peers. Even when you take into account several other demographics like education, physical activity, and income, Asians have lower BMI scores than all other ethnicities.
Additionally, there are certain instances that can make people lose weight in unhealthy ways like crash dieting and engaging in excessive physical exercise, which can decrease healthy bone mass and muscle mass.
- The BMI chart can underestimate the body fat in old people who have lost their muscle mass – As we age, we naturally lose some of our muscle mass, which often leads to weight gain or weight loss depending on the lifestyle of each person. While the reduction of muscle mass means a loss in weight and a lower BMI, this is not necessarily healthy. Having more muscle offers plenty of benefits, so weight loss should not always be your goal, especially if you are getting weaker from sarcopenia or getting older.
- Getting labeled as “overweight” does not means you are “unhealthy” – This is yet another controversial topic within the obesity research field. Some researchers found out that overweight adults who are not considered very obese are not necessarily healthy nor unhealthy. They aren’t likely to suffer from diseases or mortality within a period of time than people who fall in the normal weight range based on the BMI chart.
Here’s a major finding from American Medical Association Journal’s 2013 meta-analysis: overweight people are as healthy as individuals who have normal weight. This finding is based on the data recorded from almost a hundred studies. There is also evidence which shows overweight individuals have a lower risk of mortality than people within the normal weight range. While many authorities warn about the many dangers associated to weight gain, all the findings were very clear with the fact that adults with BMI scores between 25 and 35 didn’t have a significant increase in the risk for mortality.
To advise the country regarding the best way to handle the news, the National Health Institute states, “Those who are being labeled as ‘overweight,’ don’t have high waist measurements, and have few risk factors need to prevent gaining weight instead of exerting an effort to lose weight.” As for other authoritative figures, they encourage people who have been considered as overweight to consult their doctors regarding their risk for health concerns, especially heart disease, based on other means and measurements apart from the BMI chart.
- BMI is unresponsive most of the time – Even if you’re making a lot of change to your exercises and training routines, there’s a chance that you don’t lose weight, most especially if you are not reducing your calorie intake. All your whole food choices and physical activity levels mean you’re healthier, but unless you’re shedding those extra pounds, your BMI score won’t change.
Increased physical activity can be associated with a significant reduction in the risk of heart disease as well as mortality that’s related to heart conditions regardless of the size of the person. An individual who has added exercise into a daily routine may gain muscle and lose fat, so there’s no change in the person’s gross weight. However, the body composition would be healthier. The reason why BMI has a bad reputation is mainly that it won’t account for this particular shift.
Exercise is capable of reducing belly fat of up to 20 percent even without a change in weight. A person who’s getting close to achieving a weight goal may get healthier, but the BMI chart won’t show it, leading to the individual feeling depressed as efforts of eating better and moving more aren’t bringing results.
If this exactly is what you’re experiencing right now, don’t get frustrated. More importantly, don’t resort to going back to your unhealthy patterns. Losing fat and gaining muscle to your body frame means you are improving your overall well-being regardless of what your BMI score tells you.
Better Ways of Calculating the Ideal Body Weight for You
There are better ways for you to determine how much you are supposed to weigh. We’re not talking about having a rough idea of how much you’d want to weight. Instead, we’ll provide you with ways that can produce the number that’s appropriate for your height, weight, sex, and age. Knowing the ideal body weight you should be in will give you an idea of whether you are underweight, overweight or obese.
Waist-to-hip Ratio (WHR)
WHR is mostly used by women in calculating their ideal weight.
Waist-to-hip ratio formula:
WHR = the size of your waist ÷ the size of your hips
For instance, the measurement of your hips is at 38 inches and your waist is at 28 inches. Divide 28 (waist) by 38 (hips), and you get a total of 0.73. So, what does 0.73 mean?
For men, the ideal WHR is less than 0.9. Between .99 and .9 means you’re at risk for heart problems as you carry excessive weight. Higher than 1 WHR means an increase in the risk of heart problems.
For women, the ideal WHR is less than 0.8. Between .89 and .8 means you’re at risk for heart problems. Having a WHR that’s higher than 0.9 makes you vulnerable to heart problems.
Most of the time, it’s a reliable indicator as to whether you are at your ideal weight or not. However, it won’t provide you with an insight on how much fat or muscle you have. Also, it won’t take into account your body shape. However, it is certainly a better approach than determining the ideal weight for you through BMI.
Body Fat Percentage
If you want to find out your level of fitness, then you would want to calculate your current body fat percentage, which is a test that you will have to perform with your fitness trainer or professional nutritionist. The professional will provide you with a number that’ll indicate the percentage of your body fat.
Lower than 18 percent is the ideal for men. Women, on the other hand, should have a body fat percentage that’s less than 21 percent.
For men, 18 percent to 25 percent body fat is acceptable, and 21 percent to 24 percent for women.
For men, anywhere between 26 percent and 37 percent are overweight. For women, overweight is a body fat percentage that’s from 32 percent to 41 percent. Higher than 38 percent would indicate obesity in men while higher than 42 percent suggests obesity in women.
A Rough Formula
If you just want to get a rough idea regarding your ideal weight without taking body fat, body shape or bone density into consideration, then use this formula:
- See how many inches you are over 5 feet. 6 feet is 12 inches, 5 feet, and 8 inches is 8 inches, and 6 ft and 5 inches is 17 inches.
- Multiply the number by 6.
- Then, add the product to 106.
- Add and subtract 10 percent to the number you’ve arrived in to be able to get a range of your ideal body weight.
Say for example you are 5 feet and 8 inches tall.
- 8 x 6 is 48.
- 48 + 106 is 154.
- 154 +/- 10 percent is equal to 138-169.
Your ideal weight, from the formula, is anywhere between 138 to 169 lbs.
- Know how many inches you are over 5 feet.
- Multiply the number by 5.
- Add the product to 105.
- Then, add and subtract 10 percent to the total from the previous step and you’ll get a range of the body weight you should be in.
To give you an example, let’s say you are 5 feet and 4 inches tall.
- 4 x 5 is 20.
- 20 + 105 is 125.
- 125 +/- 10 percent is equal to 112-137.
From the formula, your ideal weight should be anywhere between 112 to 137 lbs.
Using the formulas above will help you get a good idea of what your body weight should be. You’ll also know whether it is time for you to head to the gym or not!
Using Body Type to Determine a Person’s Ideal Weight
From all that you’ve just learned, there’s one thing that’s certainly undeniable and that is the fact that your weight or measurement alone can’t determine your current health status. A good approach, better than taking your BMI score, is to focus and exert effort on reducing fat in certain areas in your body that are dangerous (e.g. waist) and maintaining muscle mass. Also, you need to remember that it does not matter what the weighing scale says as practicing healthier habits such as reducing your intake of processed foods and getting more exercise will benefit you greatly in myriads of ways.
Take Your Weight Measurement or Pay Close Attention to Your Visceral Fat
A “red flag” that you can look out for would be the accumulation of too much fat around your midsection or waist and a big or sudden change in your BMI score. Weight gain is often a result of a lifestyle change that you have made recently like changing your diet or decreasing the duration of your daily exercise routines. All these can affect your weight negatively.
Excess fat around a midsection is a sign of visceral fat that’s dangerous; it’s a risk factor for myriads of diseases. Technically, visceral fat is an excess accumulation of intra-abdominal adipose tissue. In other words, it is deep fat that is stored further underneath a person’s skin than the “subcutaneous” belly fat. It may wrap around a person’s kidneys, pancreas, liver, and other vital organs.
Several different studies conducted showed that if most of a person’s fat is located in the midsection instead of the hips, that person is at risk for type 2 diabetes, coronary heart disease, and high blood pressure. It is also found that the risk is increased when a person has a waist size that’s more than 35 inches for females and 40 inches for males.
Waist circumference, although a good screening tool, isn’t a diagnostic when it comes to an individual’s health nor a person’s body fatness. A professional healthcare provider should also perform the appropriate health assessments to evaluate the health risks and status of an individual.
How to Take Your Waist Circumference
To accurately measure your waist circumference:
- Get a tape measure and stand. Place the tape measure above your hipbones and around your stomach;
- Make sure the tape is horizontal on your waist;
- The tape must be snug around your waist. Don’t compress your skin as well;
- Take the measurements after you exhale or breathe out
Be Wary of Health Markers That Are Associated with Metabolic Disease
As a person gets older, there is a need to continually monitor and work towards improving the measurements of the conditions we will list down below which can put an individual at a higher risk for chronic diseases when deviated from the healthy or “normal” range. We’ll expound on the topics below but we suggest you talk to a physician regarding the tracking and understanding of the measurements that are related to:
- High triglycerides;
- High blood pressure or hypertension;
- Low HDL cholesterol or “good” cholesterol;
- High LDL cholesterol or “bad” cholesterol;
- High blood glucose or sugar
Reduce Risk Factors That Lead to Obesity
Additionally, you need to ensure that you make an effort at staying away from factors that lead to obesity-related diseases such as the following:
- Leading a sedentary lifestyle (having little physical activity);
- Cigarette smoking;
- Experiencing excessive amounts of stress daily;
- Eating highly processed foods; and
- Toxicity exposure
The best thing you can do which is guaranteed to better your current health status is to exercise regularly, especially as you’re getting older each day.
As you’re already aware of, muscle strength and muscle mass of older people start to decline, but strength training routines can reverse this. Exercising won’t promise to reduce your weight, but it will keep you within the healthy weight range. That’s not even taking into account that it is also capable of protecting you from diabetes and depression.
Studies have concluded that high-intensity resistance exercises induce a fast visceral fat loss compared to all other types of training activities. For you to get the benefits of exercise, you’re recommended by the US government to perform at least 75-150 minutes of aerobic exercise a week plus two sessions of exercise routines that target muscle strengthening.
Other Ways to Determine Your Current Health Status
Instead of using the BMI chart in determining your health which is incredibly unreliable, count a couple of other aspects of your life daily to better measure the status of your health.
Glasses of Water
First of all, there’s a need for you to make hydration your priority. Most physicians are concerned regarding the fact that people don’t know their bodies need water for their overall health and well-being.
But, it’s a misconception that we all need to drink at least 8 glasses of water each day as lots of factors also go into the amount of water a person needs in order to stay hydrated including activity level, climate, gender, and age. It is, therefore, recommended that a person checks the color of his or her urine instead of taking note of the amount of water consumed.
The goal, according to experts, is to have urine that’s of the color pale yellow or lighter as anything darker means the body is not getting enough water.
You already know that you need to track your blood pressure. But, we can’t stress how important the number is if you’re trying to take control over your overall health.
Hypertension is uncontrolled, but a serious complication which can arise is atherosclerosis. Essentially, high blood pressures contribute to the damaging of essential vessels in our bodies.
This increases the risk of stroke or heart attack. This means it is critical to maintaining your blood pressure within what is considered as normal. A high blood pressure means there’s resistance inside the arteries as reported by American Heart Association.
Although you don’t have to keep tabs on your blood pressure daily, it’s still important that you keep the number in check.
When it comes down to diet, a person should look at the serving count for vegetables and fruits. Also, there’s a need to cut down the consumption of high-glycemic foods as they’re the ones that will boost your blood sugar. It’s often talked about when determining the risk for diabetes, but regardless of whether you are diabetic or not, you need to get a clear picture of your diet.
Consuming a greater variety would allow you to enjoy health benefits. The chemicals that provide vegetables and fruits their colors have their own benefits health-wise. Eating a variety of colors and foods, therefore, will be good for your health.
The more fruit and vegetable servings you consume each day, the better. But, you must ensure you choose non-starchy vegetables as they can be detrimental to your health and wellness. Vegetables that are nutrient-dense provide healthy micronutrients such as vitamins and minerals.
If you consume 2,000 calories daily, the recommended servings of vegetables and fruits for you would be four or five. Eating everything from legumes to dark leafy greens will ensure you take in the essential nutrients and vitamins.
Like we mentioned earlier, you shouldn’t ignore your cholesterol. There’s a clinical significance about knowing what your bad and good cholesterol levels are. In general, your cholesterol levels need to be taken by a physician once every five years by the time you’re 20 years old.
If you have a few other risks, then you must have the number checked on more frequently as it can indicate a risk factor that’s significantly high for heart disease.
Hours Spent Sleeping
Experts suggest that people sleep 8-9 hours every night. But, the National Sleep Foundation recommends 7-9 hrs. for people over the age of 18.
Achieve at least 7 hours of sleep each night and you will lower your risk of experiencing multiple medical conditions. Sleep deprivation has already been linked to diabetes, hypertension, and even heart conditions. The shorter your sleep is every night, the higher your risk of premature death. Take note of how many hours you sleep every night instead of checking your BMI if your goal is to ensure you remain healthy.
Is BMI Applicable to Children?
According to Childhood Disease Archives, the BMI chart is the best tool currently available for monitoring the progress of the country’s campaign against obesity, which includes childhood obesity. As a matter of fact, the Health Select Committee recommends that the BMI scores of children be taken and given to parents to inform them regarding their children’s current health status. The problem is this: surveys conducted in the United States found that only 11 to 29 percent of physicians and pediatricians calculate the BMI measurements of children during routine visits.
Barriers that doctors reported regarding BMI use with children include disliking stigmatizing children and telling them that they are overweight or obese at such a vulnerable age, not fully believing BMI as an excellent predictor of being healthy or unhealthy, not having enough time to conduct the test during checkups, and not having good advice to give to the parents of children regarding how overweight children should lose weight.
The Relation Between a Mother’s BMI to Childhood Obesity
Childhood obesity is a global problem and it’s steadily affecting low- and middle-income families in urban settings. The prevalence, as of late, increased at a disturbing rate. Last year alone, the number of children considered as overweight was estimated to be more than 41 million. Half of the overweight children who were under 5 years of age lived in Asia. A quarter resides in Africa.
Obese and overweight children are more likely to stay overweight or obese into adulthood. They’re also likely to suffer from non-communicable diseases such as cardiovascular disease and diabetes at an early age. Obesity and being overweight are largely preventable, which means childhood obesity prevention should be a high priority.
There are those who believe that a pregnant woman’s BMI indicates childhood obesity as obese or overweight pregnant women causes the delivery of heavier babies. However, there is no sufficient evidence that supports this belief.
What’s widely accepted, instead, is the fact that childhood obesity is a result of a child’s imbalance of energy intake and energy expenditure. Also, there’s increasing evidence that indicates that a mother’s genetic background is, in fact, important in the determination of obesity risk instead of the mother’s BMI.
Research has given us an understanding of the factors that are associated with obesity in children. The ecological model suggests that risk factors in children include sedentary behavior, physical activity, and dietary intake. The impact of the risk factors can be moderated by factors like age and gender. But, the lifestyle of the parents, parenting style and family characteristics also play a massive role. School policies, the work-related demands of the parents, and demographics among other environmental factors influence activity and eating behaviors.
With that being said, genetics is the biggest factor that causes obesity in children and adults alike. There have been studies that proved BMI is around 25 percent to 40 percent inheritable. Still, genetic susceptibility is required to be paired with contributing behavioral and environmental factors to affect weight.
Listed below are the main causes of childhood obesity, which you’ll find to be unrelated to a mother’s BMI during pregnancy.
Fast Food Consumption
The increase in fast food consumption can be linked to childhood obesity. Several families with both parents working opt for fast food chains as they’re often favored by children. They are also inexpensive and convenient. Foods served at these places contain a high number of calories without having nutritional values.
Studies have been conducted to examine the daily eating habits of overweight and lean adolescents at fast food chains. The researchers found that the two groups consumed a higher number of calories eating food from restaurants than they would consume within a home setting. However, the lean group managed to compensate for the high-calorie intake by making an adjustment to their intake of calories before or after a fast food meal to anticipate or compensate for the excess calories consumed.
While the use of electronic media and extensive TV viewing contribute to a sedentary lifestyle, there are other environmental factors that reduce the opportunity for physical activity. Lately, opportunities to be active and safe surroundings to be physically active in have significantly reduced. In the past, the majority of children walked or rode bikes to school. In 2002, a study conducted found that more than 50 percent of parents have driven their kids to school. Out of these parents, 60 percent said they send their kids to school themselves since their homes are from a distance. Other reasons the parents gave included fear of predators, the absence of walking routes, and for the child’s convenience.
Socio-cultural factors also influence obesity development in children. The society we live in tends to use food and sugary beverages as rewards. They may also be used as a method to control others as well as a part of socializing. This unhealthy relationship with food increases the risk for childhood obesity.
The family factors that are associated with the increase of obesity cases include the kinds of food available within a home as well as a family’s food preferences. In addition, meal times can influence what type of food is consumed. Lastly, habits of family members, whether they are physically active or sedentary, influence the child.
Studies have revealed that having a mother that’s obese or overweight and living in a household of a single parent can be linked to childhood obesity.
Depression and Anxiety (Psychological Factors)
Majority of studies conducted on childhood obesity found a relationship between depression and eating disturbances. However, the prospective relationship isn’t unidirectional as depression may be a consequence and cause of childhood obesity. Additionally, it’s certainly inconclusive as there’s been no relationship between an increase in BMI with increased anxiety symptoms. Regardless, physical activity can have a positive effect on both the mental and physical health of children.
BMI Prime, a simple modification of BMI, can be calculated by dividing your BMI score by 25, which is the upper limit for a normal, healthy BMI. Individuals that are within the BMI range of 0.74 to 1 can be considered as healthy and normal. For individuals that have a BMI prime score that’s lower than 0.75, they’re considered as underweight. A BMI prime that’s more than 1 is considered as overweight.
BMI Prime, unlike the BMI chart, sets excellent markers and targets of 1, 0.9, 0.8, and so forth, giving people who are monitoring their weight loss a sense of progress which is why it’s a preferred measurement. Its ease and simplicity to measure have made it common within the health and medical field. But, just like BMI, it should not be considered as an absolute score. Instead, it should be seen as a mere indicator.
The Takeaway on Measuring Body Weight and BMI
Body mass index is just one of the many screening tools available today. From the article, you already know how to assess you or another person’s health risk. Also, you know that having a higher BMI score does not necessarily mean that your health is already doomed. As a matter of fact, you can be perfectly healthy even when your BMI score doesn’t say so.
Taking all factors into account, which include your family and personal health history, as well as a thorough measurement of your body can be combined with your BMI prime range as they all give you a clear and concise picture of both your current and future health status.