Post No.: 0994
Furrywisepuppy says:
Your body mass index (BMI) is calculated by dividing your weight (in kilograms) by your height (in metres) squared. A BMI of <18.5 is considered underweight; 18.5-24.9 is considered in the healthy range; 25-29.9 is considered overweight; 30-39.9 is considered obese; and ≥40 is considered severely obese. (These ranges are adjusted for certain ethnicities.) The more you deviate from the healthy range in either direction, the more you’re statistically at risk of developing health problems and an early death.
BMI is quite a crude measure of adiposity and mortality risk however because fit and muscular people can be heavy for their height because muscle mass is dense (denser than fat). Some others within the healthy range could be carrying lots of visceral fat even if they don’t have as much subcutaneous fat. Excessive visceral fat, or the fat around one’s internal organs, is the most dangerous location for fat – and this fat isn’t externally visible except if one has lots of belly fat, which is a bad sign. BMI also isn’t accurate for those who are pregnant or elderly.
So BMI doesn’t distinguish between fat, muscle or bone mass. And sometimes it’s difficult to tell what somebody’s muscle-to-fat ratio is just by simply looking at them – as in do they have a lot of muscle under their subcutaneous fat? A doctor will or should however explore further to determine if a patient’s high BMI is due to excess adiposity. It may be blatantly obvious to yourself whether your obesity is due to your excess calorie consumption as opposed to your muscle gains though!
When gathering calorie consumption versus BMI data, some people who have low and medium BMI levels may consume enormous amounts of calories – but that’s simply because they’re athletes in training thus they’re burning plenty of calories off too. Meanwhile, some overweight and obese people may only be consuming moderate amounts of calories – but that’s because they’re currently on controlled diets and are trying to lose weight. It’s thus critically vital to read and understand the details when assimilating science news, and not just rely on the (clickbait) headlines.
Instead of BMI – relatively more accurate measures of body fat percentage include hydrostatic weighing, using air displacement plethysmography (a ‘bod pod’) or taking a dual energy x-ray absorptiometry (DEXA) scan. Simply measuring one’s waist-to-hip ratio is a better way to gauge one’s subcutaneous fat than BMI.
Better measures of general health risk include measuring one’s blood pressure, blood lipids, insulin resistance and cardio-respiratory fitness. Health cannot be reduced to just one or two numbers – it requires a wide array of them measuring different things like one’s lifestyle, biology, fat, muscle mass, diet, activity levels and more.
Obesity itself isn’t a cause for mortality but is strongly associated with an increased risk of numerous diseases or conditions including heart disease, hypertension, stroke, type 2 diabetes, liver disease, gall bladder disease, pulmonary disease, cardiovascular disease, atherosclerosis, bone and joint problems like osteoarthritis, menstrual irregularities in women, reproductive problems, cancers of the colon, breast, uterus, cervix and prostate, breathing problems like obstructive sleep apnoea and asthma, low self-esteem and depression, and more acute symptoms after contracting contagious diseases like COVID-19… amongst other problems – any of which could accelerate one’s mortality or at least degrade one’s quality of life.
Having any of these diseases increases your risk of other problems too, like diabetes can lead to blindness and/or uropathy.
According to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) – 3+ out of 5 problems involving one’s waist circumference (central obesity), serum triglyceride levels, HDL levels, blood pressure, and fasting blood glucose levels (metabolic fitness), will mean one has metabolic syndrome.
Although being obese might improve one’s chances of surviving a wasting disease a bit longer (if one ever contracts one – and you really don’t want to!) and may help protect one against certain injuries (since fat acts like a cushion), the risks far outweigh the benefits. Being overweight (but not obese or severely obese) might possibly help one to recover faster after heart surgery because such procedures are draining on the body’s resources? Albeit even if true, if one were fitter then one more likely wouldn’t have required such a major surgical procedure in the first place!
Overweight patients may be prioritised and treated more aggressively than non-overweight patients who develop health problems (after all, those with a ‘healthy weight’ can still get ill). All this could skew research data.
Being categorised as ‘overweight’ may not be itself problematic but it’s noted because one could be on the road towards becoming ‘obese’. And because prevention is generally better, easier and cheaper than treatment – people must pay attention to how their weight may be changing over time.
Modern medications (e.g. statins), therapies and surgical procedures can stave off an early death in obese people, at least for a while and as long as the weight doesn’t continue to increase. Indeed, obese patients do generally receive a lot of medical attention and intervention, and doctors scrutinise heavier patients for disease symptoms more extensively because they know that excess fat signals a health risk that could accelerate their mortality.
Being categorised as ‘underweight’ is correlated with an increased risk of malnutrition, osteoporosis, hypothermia, low muscle strength and lowered immunity levels. Being underweight is typically worse for one’s health than being obese when it comes to mortality. We all need some fat or energy reserves to be healthy hence no good doctor would ever say that fat is unequivocally bad for you.
But weight alone has become an unrefined proxy for one’s health; just like money has become an unrefined proxy for attaining happiness. To some extent these easily measurable proxies correlate well with what they intend to represent – but at broad parts of the spectrum they don’t. Consequently, some people’s attempts at losing weight ironically come at a cost to their health; just like some people’s attempts at making more money than they need come at a cost to their health and thus happiness. (You can have all the money in the world but without health you’re nothing. When we want our economy to be prosperous, we want it to be so because we ultimately want the population to be healthy, happy and well. And with good health and cooperation, we can achieve just about anything imaginable.)
Like BMI – ‘biological age’ is perhaps also another measure that’s misleadingly reduced to a single number when we might have different separate ‘ages’ (relative to the rest of the population) for our hearts, lungs, skin, brain, etc..
Where the BMI classification thresholds are drawn are open to debate too – the World Health Organisation has even changed what BMI values are classed as ‘overweight’ and ‘obese’ before. Having said this – health professionals will rely more on the precise value of a patient’s BMI and understand that the closer this value is to the healthy range, the better.
Yet having said that – it was the International Obesity Taskforce that produced a report that was funded by drug companies that manufacture weight-loss pills that informed this change. And it was in these companies’ self-interests to lower the threshold for people being classed as ‘overweight’ so that more people in the world would be prescribed their products! It’s a recurring pattern in probably every industry or sector on Earth (or in the solar system once companies commercialise space) how for-profit self-interests interfere with either finding and publishing the pure truth or doing the absolute best thing for people and the world! It’s a pattern one learns about for having deep furry educational interests in so many fields. Follow the money!
One proposed better clinical measure for measuring body fat percentage than BMI is measuring people’s body adiposity index (BAI), which uses one’s hip circumference measurement in relation to one’s height. It doesn’t really overcome the limitations of BMI but requires even less equipment (just a tape measure). Measuring one’s waist-to-height ratio may be better than either BMI or BAI.
In the end, health is ultimately determined by the performance and ability of one’s organs and body, not by superficial measures like one’s weight, height or how one looks.
But BMI is a simple measure to conduct using widely accessible equipment (just a tape measure and weighing scales). And when conducting studies where we’re trying to assess the general health of a population overall – BMI is a practical and reasonably reliable single measure for doing so.
When assessing individuals however, BMI is hardly a perfect or comprehensive measure of health. We must understand its limitations. Yet it’s nevertheless a useful screening tool for judging the approximate health risks of an individual, and can act as a springboard for conducting more specific follow-up tests that evaluate their health status in more detail.
Indubitably what matters infinitely more than how much you weigh or how you look is how well you can perform. The VO2 Max or Balke treadmill protocol test is one such test of your cardiovascular fitness. Although ‘looking good’ is subjective (and there exist many physically fit people who are arrogant or have other lousy personality traits thus aren’t everybody’s cup of tea!) – you’ll likely look good if you’re metabolically fit, whereas looking good doesn’t necessarily mean one is metabolically fit. One can weigh and look ‘normal’ but if one drinks alcohol excessively, smokes or doesn’t do enough regular physical activity then one isn’t going to be fit, whereas someone who’s considered ‘overweight’ could technically be ‘in better shape’ than you.
And if you’re obese and are regularly exercising yet cannot seem to shift the weight off – don’t feel disheartened because you could be gaining muscle mass as you lose fat mass. So carry on. We don’t have to be an athlete-in-training to reduce our risk of obesity-related diseases and to enjoy feeling fit!
Although, if you’re above a healthy BMI, every kilogram you lose will statistically lower your risk of developing an obesity-related disease, thus rapidly dropping off a lot of weight is better than nothing – steady weight loss tends to be less stressful and more sustainable for most people as this reduces the risk of physical and mental burnout after changing one’s lifestyle and diet.
Obese people are already carrying plenty of weight hence walking is likely going to be enough to get them exercising – no need for an expensive gym membership or to buy any gym equipment whatsoever; at least yet. And walking is obviously useful in the real world too, which means walking more can be seamlessly incorporated into one’s daily life, such as walking to and from the shops, or work if possible.
Explore and use your local public spaces and free facilities – walking around local beauty spots, such as hills and beaches, gets 5 dewclaws up from a dog. Woof!
If an active 70-year old person is metabolically fitter than a 40-year old person then it’s not that the former has ‘reversed their age’ but the latter isn’t active enough and is considered ‘biologically old’ for their age.
The attitude of expecting pills and cosmetics – rather than regular exercise, a healthy diet, sleeping well, drinking less/no alcohol and not smoking to live longer – doesn’t help us to understand that people aren’t fit for their age but many people are simply quite unfit for their age. People don’t die from old age per se but from diseases that become more common as people age. And again there are diseases that become more common the more people become overweight.
Woof. I’m not anti-obese – I’m pro-health and fitness. Keeping fit is so vital for so many reasons in life. It most of all simply feels good and boosts one’s confidence (mental health) to be in a healthy condition. Look after yourself in sustainably healthy ways and you’ll feel good. Feel good and you’ll look after yourself. It’s a virtuous cycle. The challenge for many is getting onto this cycle.
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