By Dr. Mercola
Provocative new research involving data from nearly 3 million adults suggests that a having an overweight body mass index (BMI) may be linked to a longer life than one that puts you within a "normal" weight range.
The research, which analyzed 97 studies in all, found that people with BMIs under 30 but above normal (the overweight range) had a 6 percent lower risk of dying from all causes than those who were normal weight, while those whose BMIs fell into the obese range were 18 percent more likely to die of any cause.1 The researchers wrote:
"Relative to normal weight … overweight was associated with significantly lower all-cause mortality."
Do a Few Extra Pounds Make You Healthier?
The study results imply, at least superficially, that carrying some extra weight may help you live longer … or at the very least may not be as unhealthy as it's made out to be. In a JAMA editorial, Steven Heymsfield, M.D. and William Cefalu, M.D. highlighted this notion:2
"The presence of a wasting disease, heart disease, diabetes, renal dialysis, or older age are all associated with an inverse relationship between BMI and mortality rate, an observation termed the obesity paradox or reverse epidemiology.
The optimal BMI linked with lowest mortality in patients with chronic disease may be within the overweight and obesity range.
Even in the absence of chronic disease, small excess amounts of adipose tissue may provide needed energy reserves during acute catabolic illnesses, have beneficial mechanical effects with some types of traumatic injuries, and convey other salutary effects that need to be investigated in light of the studies … "
Indeed, it is quite possible to be overweight and healthy, just as it's possible to be normal weight and unhealthy. But for the vast majority of those who carry around extra pounds, health problems will often result.
The study has been heavily criticized for painting an overly simplistic picture of a very complex situation. For instance, it doesn't tell you whether those living longer were afflicted with more chronic disease or whether their quality of life was otherwise impacted. And even more importantly, it used only BMI as a measure of body composition, and this is a highly flawed technique.
Many studies, such as one published in the Journal of the American College of Cardiology,3 have actually found that a high BMI was associated with a lower risk of death, a phenomenon known as the "obesity paradox." But these findings are typically only examples of how BMI is such a flawed measurement tool …
Why BMI is a Flawed Measurement Tool
If you'd like to know how much body fat you have and whether or not your levels put you into a weight category that might lead to health problems, most public health agencies, and therefore most physicians, promote the use of the BMI, which gauges weight in relation to height. But this method is quite flawed, as research suggests it may underestimate obesity rates and misclassify up to one-quarter of men and nearly half of women.4 According to lead author Dr. Eric Braverman, president of the nonprofit Path Foundation in New York City:5
"Based on BMI, about one-third of Americans are considered obese, but when other methods of measuring obesity are used, that number may be closer to 60%."
One of the primary reasons why BMI is such a flawed measurement tool is that it uses weight as a measure of risk, when it is actually a high percentage of body fat that makes a person have an increased disease risk. Your weight takes into account your bone structure, for instance, so a big-boned person may weigh more, but that certainly doesn't mean they have more body fat.
Athletes and completely out-of-shape people can also have similar BMI scores, or a very muscular person could be classified as "obese" using BMI, when in reality it is mostly lean muscle accounting for their higher-than-average weight. BMI also tells you nothing about where fat is located in your body, and it appears that the location of the fat, particularly if it's around your stomach, is more important than the absolute amount of fat when it comes to measuring certain health risks, especially heart disease.
Do You Know Your Body Fat Percentage?
This is another useful tool that is leaps and bounds ahead of BMI as far as gauging your weight-related health risks is concerned. It is FAR better to monitor your body fat percentage than it is your total weight, as the body fat percentage is what dictates metabolic health or dysfunction – not your total weight.
Too much body fat is linked to chronic health problems like high blood pressure, high cholesterol, heart disease, diabetes, and cancer, while too little body fat is also problematic and can cause your body to enter a catabolic state, where muscle protein is used as fuel.
Body fat calipers are one of the most trusted and most accurate ways to measure body fat. A body fat or skinfold caliper is a lightweight, hand-held device that quickly and easily measures the thickness of a fold of your skin with its underlying layer of fat. Taken at three very specific locations on your body, these readings can help you estimate the total percent of body fat within your entire body.
You can also use a digital scale that determines body fat, which is what I use personally. I use an Eat Smart Precision GetFit Body Fat Scale that I picked up from Amazon for around $50. Although many body fat measurements can be inaccurate, they are nearly all more accurate than BMI, and are particularly useful to determine whether you are gaining or losing fat. Although the absolute value may be off, the direction you are going (whether your body fat is going up or down) will be very accurate, and this is an incredibly useful measure of whether you're nearing your health goals or not. A general guideline from the American Council on Exercise is as follows:6
|| Women (percent fat)
|| Men (percent fat)
| Essential Fat
|| 10-13 percent
|| 2-5 percent
|| 14-20 percent
|| 6-13 percent
|| 21-24 percent
|| 14-17 percent
|| 25-31 percent
|| 18-24 percent
|| 32 percent and higher
|| 25 percent and higher
Overweight Often Leads to Obesity…
It is quite clear that the more overweight you are, the greater the health risks become. So even if it were true that a few extra pounds are actually good for you, if you're on a path of weight gain you're on a slippery slope that could easily lead to obesity.
The most recent health report card issued for the United States predicts that half of all American adults will be obese by 2030. Obesity-related illness is predicted to raise national health care costs by $48 billion annually over the next two decades by adding another 7.9 million new cases of diabetes, 5 million cases of chronic heart disease and stroke, and 400,000 cancer cases…7 If you want to avoid becoming one of these statistics, I suggest you start to look at your weight as less a product of "calories in vs. calories out" and more the result of a faulty "fat switch." According to Dr. Richard Johnson of the University of Colorado, author of The Fat Switch:
"Those of us who are obese eat more because of a faulty 'switch' and exercise less because of a low energy state. If you can learn how to control the specific 'switch' located in the powerhouse of each of your cells – the mitochondria – you hold the key to fighting obesity."
Here are some highlights that Dr. Johnson explains in detail in his book:
- Large portions of food and too little exercise are the result of your fat switch being turned on
- Metabolic Syndrome is the normal condition that animals undertake to store fat
- Fructose-containing sugars cause obesity not by calories but by turning on the fat switch
- Effective treatment of obesity requires turning off your fat switch and improving the function of your cells' mitochondria
I highly recommend picking up a copy of this book, which has been described as the "Holy Grail" for those struggling with their weight. Dietary sugar, especially fructose, is a significant "tripper of your fat switch," which is why, if you are serious about losing weight, you'll need a comprehensive plan that includes: