By Dr. Mercola
In the last decade, researchers have been exploring the paradox of "metabolically healthy" overweight or obesity, which describes people who are carrying excess weight without any of the corresponding health problems that typically go along with it.
Is it possible to be overweight or obese and healthy? Yes, just as it's possible to be normal weight and unhealthy. But is it likely? Probably not, according to the latest research.
Healthy Obesity: What Does the Research Say?
Last year, data from nearly three million adults suggested that 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
There were problems with this study, however, as there often are in those that seem to show a positive effect of obesity. 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 in determining if a person is truly obese and it fails to differentiate between muscle and fat tissue.
Many studies, such as one published in the Journal of the American College of Cardiology,2 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.
Still, other research published last year also tried to find out whether metabolically healthy obesity was a myth, and revealed that it appeared to be a "transient state" for one-third of the study participants.3 In other words, many who appear to be healthy will end up with health problems down the road.
Not surprisingly, those who continued to be metabolically healthy and obese were younger and had a smaller waist circumference. However, the latest research, which may be the most comprehensive to date, suggests that metabolically healthy obesity simply doesn't exist.
'You Can't Be Fit and Fat'
This was a recent headline from TIME, describing the results of a new Annals of Internal Medicine4 study, which concluded that there's no such thing as being "healthy" and obese.
The study, a systematic review and meta-analysis that included data from more than 61,000 people, found that obese individuals were more likely to die sooner or have heart-related problems than people of normal weight – even if they were otherwise healthy. The researchers concluded:
"Compared with metabolically healthy normal-weight individuals, obese persons are at increased risk for adverse long-term outcomes even in the absence of metabolic abnormalities, suggesting that there is no healthy pattern of increased weight."
As for why past studies have supported the notion that you can be fit and fat, the featured study's lead author pointed out several problems with how some of the studies were set up:5
- Some studies only looked at risk of adverse events, rather than measures of metabolic health. So if an overweight person avoided an adverse event during the study, they could be classified as healthy even though they may have had underlying signs of diabetes or high blood pressure that the study didn't look for.
- Some studies compared healthy obese people to unhealthy obese people, instead of comparing them to healthy normal-weight people.
- Some studies only used small groups of participants or short time periods, which may have missed problems in larger populations or that occur over time
Health Risks Rose with Increasing BMIs
It should be noted that the study did not find an increased risk of death or cardiovascular problems among those who were overweight and metabolically healthy, compared to those of normal weight and metabolic health. However, it did reveal that everyone with poor metabolic health had increased risk, regardless of their weight status.
Please realize that you can have metabolic dysfunction and be prone to obesity-related diseases even if your bodyweight is fine. This is one more reason why you can't rely on your BMI alone, as it won't give you the complete picture of your health.
However, according to the featured study, health risks did go up as BMI increased, which suggests that as your weight creeps up, so to do your health risks. And even if you're healthy now, that might not be true for long. As the Los Angeles Times reported:6
"When researchers used BMI to line up all of the 61,386 subjects who participated in the eight studies they pooled, they found that, as BMI rose, so rose blood pressure, waist circumference and insulin resistance.
As BMI increased, levels of HDL cholesterol, thought to protect against heart attack and stroke, decreased. Though overweight and obese subjects may not yet have reached the points that define metabolic illness, they appeared to be on that road as their weight rose."
Obesity Won't Kill You… But Its Complications Might
Obesity itself is rarely listed as a cause of death. Instead, the complications of obesity, such as heart disease or diabetes, are blamed for a person's death. If you are obese, your risk for a number of serious health problems multiplies.
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 Eight obesity-related diseases account for a staggering 75 percent of healthcare costs in the US. These diseases include:
|Type 2 diabetes ||Non-alcoholic fatty liver disease (NAFLD)
|Hypertension ||Polycystic ovarian syndrome
|Lipid problems ||Cancer (especially breast, endometrial, colon, gallbladder, prostate, and kidney8)
|Heart disease ||Dementia
The four diseases in the left column are associated with metabolic syndrome, which is a common factor in obesity. However, several other diseases fall within this category as well, which are listed on the right. And many more could be added to that list. According to the Surgeon General, in addition to the diseases mentioned above, obesity increases your risk for asthma, sleep disorders (including sleep apnea), depression, pregnancy complications, and poor surgical outcomes.9
While obesity is associated with metabolic syndrome and the diseases mentioned above, it is not their cause; it is simply a marker. The common link among them is metabolic dysfunction, and excessive sugar/fructose consumption is a primary driver. Even if you don't yet have clinical signs of metabolic dysfunction, the fact that you're gaining excess weight is sign enough.
If You're Overweight, You're Probably Already Leptin Resistant
You see, most overweight Americans have some degree of insulin and leptin resistance. Generally, in order for you to significantly gain weight, you must first become leptin resistant. Leptin is a hormone that helps you regulate your appetite. When your leptin levels rise, it signals your body that you're full, so you'll stop eating.
However, as you become increasingly resistant to the effects of leptin, you end up eating more. Many people who are overweight also have an impairment in their body's ability to oxidize fat, which leads to a low-energy state. Dr. Richard Johnson's research clearly shows that refined sugar (in particular fructose) is exceptionally effective at causing leptin resistance in animals, and it's very effective at blocking the burning of fat.
If you are insulin or leptin resistant, as long as you keep eating fructose and grains, you're programming your body to create and store fat...This is one of the key reasons why, if you are overweight (which means you are also likely insulin or leptin resistant), it would be prudent for you to restrict your fructose consumption to about 15 to 25 grams of fructose per day from all sources. Not only will this help you to avoid additional weight gain, it will also help you to avoid further metabolic dysfunction. You may find this fructose chart helpful in estimating how many grams of fructose you are consuming each day.
Two Better Ways to Measure Your Health Risks Than BMI
Using BMI to gauge obesity is a seriously flawed index that doesn't take into account your percentage of body fat or the distribution of that fat. When those variables are factored in, the number of people who meet the criteria for obesity is MUCH higher—possibly even twice as high! As far as simple indicators go, waist to hip ratio is a better predictor of heart disease risk than body weight or BMI. A large waist size is a powerful predictor of being unhealthy because it is a sign that you have too much intra-abdominal or visceral fat that surrounds your liver, kidneys, intestines, and other organs. This is also known as the classic apple-shaped obesity. Thankfully, this is also one of the first signs that will change as a result of your program. So before you start your weight loss program, get a tape measure and record your waist and hip circumference.
|Waist to Hip Ratio||Men||Women
|Ideal ||0.8 ||0.7
|Low Risk ||<0.95 ||<0.8
|Moderate Risk ||0.96-0.99 ||0.81 - 0.84
|High Risk ||>1.0 ||>0.85
You can also use body-fat calipers or a digital scale that determines body fat to figure out your body fat percentage. 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:10
||Women (percent fat)
||Men (percent fat)
||32 percent and higher
||25 percent and higher
Are You Serious About Getting Metabolically Healthy?
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 the following. This plan will help most people lose weight but, also, it will help you to gain metabolic health. So even if your weight is normal, you can follow this plan to ensure that you're metabolically healthy as well.