BODY MASS INDEX
Body Mass Index, or BMI, is a health indicator used to determine whether you’re underweight, a healthy weight, overweight, or obese when your weight is compared to your actual height. This indicator has been used for generations and has largely remained unchanged. According to the World Health Organization, "as BMI increases, so does the risk for some diseases."
WHAT DOES IT MEAN? Not interested in the history? You could totally skip this!
The idea of BMI was established in the first half of the 19th century by Adolphe Quetelet (1796-1874), a Belgian astronomer, statistician and sociologist who wanted to measure the human body to determine the “average man,” based on statistical evidence. With no particular interest in the study of obesity, Quetelet established an equation mixing your height and weight, the Quetelet’s Index. Although this formula was proposed in 1832, it wasn’t actually dubbed “BMI” until 1972.
Popularized over the 20th century, the BMI formula is still a standard way to determine obesity:
BMI = weight(kg) / height (m²)
BMI is acknowledged as a way to discuss weight problems more objectively. No matter how tall, thick, or big-boned you are, your BMI goal will remain the same.
Which factors affect BMI results?
Although many studies confirm the relationship between a high BMI score and potential risks to your health, it is important to keep in mind that BMI measures excess weight and not excess body fat. You may be neither overweight or obese, but still have dangerous levels of excess fat. To assess your overall health, you should regularly measure your body fat percentage.
“Adults and children who have not been classified as obese or overweight can still be overfat.”
The Problem with BMI
Unfortunately, BMI does not tell the whole story. If you attempt to determine your ideal weight based on a BMI calculation, it’s important to take the following factors into consideration:
1. AGE: Older adults tend to have more body fat than younger adults for an equivalent BMI according to the CDC.
2. MUSCLE FAT RATIO: Muscle is heavier than fat, therefore you may have an unhealthy amount of body fat, but think that you are not overweight based on your BMI results.
3. GENDER: BMI values in women are generally lower than men, however differences in metabolism mean that women may carry slightly more fat. Though the situation in India seems otherwise.
4. BODY SHAPE: The European Heart Journal states that body shape and the location of fat deposits may better indicate potential cardiovascular problems in women than BMI. Indeed, your body's fat distribution is a crucial factor for assessing overweight and obesity.
Which risks are associated with a body mass index that is too high?
If you are not physically active, having a body mass index that is too high can increase the risk of many health complications. Among them, obese people have a significantly higher risk of developing:
Cardiovascular diseases:
Excess weight increases the heart’s work, which can lead to heart failure. The European Society of Cardiology states that "as body mass index and fat mass increase, so does the risk of aortic valve stenosis,” which is a particular form of valvular heart disease.
Type 2 diabetes MELLITUS:
Although it is not completely clear why obese people are more likely to develop this condition, studies show that obese people are 80 times more likely to develop type 2 diabetes compared with those with a BMI of less than 22. Insulin resistance might in fact be triggered by “pro-inflammatory” chemicals released by an excess of fat cells.
Which risks are associated with a body mass index that is too low?
If your BMI is less than 18.5, this suggests that you may be underweight.
You may experience health consequences such as nutrient deficiencies, a weakened immune system, and even hormonal issues. A low BMI also increases the risk of osteoporosis, a condition in which the bones may become weak and break easily.
Recent studies using data from the CDC’s Behavioral Risk Factor Surveillance System showed evidence that being underweight is also a risk factor for cardiovascular diseases, with a significantly higher risk of stroke.
Body Mass Index vs. body fat percentage: What works best?
Keep in mind that a healthy weight requires a healthy body composition. Designed as a statistical tool for studying populations rather than individuals, BMI should not be the only metric you should rely on to determine your fitness weight.
The American Society of Bariatric Physicians, which publishes studies about weight loss, defines obesity as a body-fat level of 25% and above for men and 30% and above for women. Thus, many people fall into the “obese” category, even though their BMI results do not classify them as obese.
When looking at body fat distribution, it is also important to define a particular type of fat, called visceral fat. Often called the “belly fat” because it is stored in the abdomen, an excess of visceral fat can be particularly dangerous, because it wraps around major organs like the kidneys, the liver, or the pancreas, and may create inflammation. Visceral fat is associated with the development of insulin resistance, the risk of coronary heart disease, and hypertension.
HEART RATE
A healthy heart doesn't beat with the regularity of clockwork. It speeds up and slows down to accommodate your changing need for oxygen as your activities vary throughout the day. A "normal" heart rate varies from person to person. However, an unusually high resting heart rate or low maximum heart rate may signify an increased risk of heart disease or other medical condition.
RESTING HEART RATE: When you are at rest, your heart is pumping the lowest amount of blood to supply the oxygen your body's needs. Although the official normal resting heart rate ranges from 60 to 100 beats per minute, the range for most healthy adults is between 55 and 85 beats per minute. However, other factors can affect your resting heart rate, such as
1. Stress
2. Anxiety
3. Hormones
4. Medication
5. Physical activity level
What is a good resting heart rate?
There is no specific good resting heart rate. Well-trained athletes can have numbers in the 40s. But a heart rate that slow for the average person would be concerning and should prompt a call to your doctor's office, especially if you felt weak, lightheaded, or short of breath.
On the other end of the scale, a resting heart rate that is consistently above 90 beats per minute is also something your doctor should be aware of. Although it is still formally still normal, it could be a clue of something amiss, but not necessarily a serious problem. So check your pulse and refer to the table below.
