Although obesity has long been known to be a risk factor for heart disease, several studies have found that a high body mass index is actually associated with a lower risk of dying from heart ailments. However, according to a new analysis, the apparent paradox may be explained by the simple fact that BMI is a very flawed measurement.

The study revealed that waist size provides a far more accurate way to predict a heart patient's chances of dying at an early age from a heart attack or other causes.

CNN reports:

As in previous studies, a high BMI was associated with a lower risk of death. But researchers found that heart patients with a high ratio of waist-to-hip circumference or a large waist size -- greater than 35 inches for women, or 40 inches for men -- were 70 percent more likely to die during the study period than those with smaller waists. The combination of a large waist and a high BMI upped the risk of death even more.

Dr. Mercola's comments

A thick waist is a well-known sign of a build-up of visceral fat, a dangerous type of fat around your internal organs that is strongly linked with type 2 diabetes and heart disease. Yet, it is body mass index (BMI), which gauges weight in relation to height that is often used to predict heart disease risks.

Now another study has shown what many before it already have, which is that your waist size is a far more accurate predictor of your heart risks than your BMI. Researchers even called BMI "the total cholesterol of lipids" because, like total cholesterol, BMI is far too vague to tell you much about your heart health.

Good news - waist size strongly predicts your heart risk!

A new study in the Journal of the American College of Cardiology found that heart patients with a large waist size (greater than 35 inches for women and 40 for men) were 70 percent more likely to die during the study than those with smaller waists.

The study also found, like some previous studies have, that a high BMI was associated with a lower risk of death, a phenomenon known as the "obesity paradox." The researchers noted this finding as an example of how BMI is a flawed measurement tool, as it tells you nothing about where fat is located in the body, and it appears that the location of the fat is more important than the amount of fat when it comes to measuring heart risks.

In fact, when BMI was combined with waist size, those with high measures of both had the highest death risk of all.

BMI also neglects to mention how muscular you might be. Athletes and completely out-of-shape people can 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.

What makes a large waist so risky?

Your body has two types of fat: visceral and subcutaneous. Subcutaneous fat is found just under your skin, and is the type that causes dimpling and cellulite. Visceral fat, on the other hand, shows up in your abdomen and surrounds your vital organs including your liver, heart and muscles.

This "visceral fat" is strongly linked with type 2 diabetes, heart disease, strokes, and other chronic diseases. It is thought that visceral fat is related to the release of proteins and hormones that can cause inflammation, which in turn can damage arteries and enter your liver, affecting how your body breaks down sugars and fats.

When your body routinely stores excess visceral fat, you increase your risk for high blood pressure, high cholesterol, vascular disease, atherosclerosis (hardening of your arteries) and an increased thickness in the walls of your heart.

Your waist size is also a powerful indicator of insulin sensitivity, as studies clearly show that measuring your waist size is one of the most powerful ways to predict your risk for diabetes.

While visceral fat is often referred to as "belly fat" because it can cause a "beer belly" or an apple-shaped body, you can have visceral fat even if you're thin. As CNN reported regarding the Journal of the American College of Cardiology:

Even heart patients with apple-shaped bodies and BMIs in the normal range were at increased risk of dying sooner, which drives home the fact that normal-weight heart patients may need to lose some weight in their bellies too …

Is your waist in the healthy size range?

Determining your waist size is easy. With a tape measure, figure the distance around the smallest area of your abdomen below your rib cage and above your belly button. If you're not sure if you have a healthy waist circumference, a general guide is:

• For men, between 37 and 40 inches is overweight and more than 40 inches is obese
• For women, 31.5-34.6 inches is overweight and more than 34.6 inches is obese

             

What you need to know about leptin and inflammation …

The hormones your fat cells produce impact how much you eat and how much fat you burn. One of these hormones is leptin, and leptin sends signals that reduce hunger, increase fat burning and reduce fat storage. That is, if your cells are communicating properly and can "hear" this message.

If you are eating a diet that is high in sugar and grains -- this is the same type of diet that will also increase inflammation in your body -- as the sugar gets metabolized in fat cells, fat releases surges in leptin. Over time, if your body is exposed to too much leptin, it will become resistant to the leptin (just as your body can become resistant to insulin).

Leptin resistance causes an increase in the visceral fat your body produces. Likewise, it is through an inflammatory process that it's thought visceral fat causes its damage, and the same diet that makes you leptin resistant will also increase inflammation in your body.

So by tending to this one factor -- diet -- you can reduce your risk of both becoming leptin resistant and triggering chronic inflammation in your body.

Dietary change #1: severely limit fructose

The single largest source of calories for Americans comes from fructose, a type of sugar that's loaded into your soft drinks, fruit juices and sports drinks, and hidden in most processed foods -- from bologna to pretzels to Worcestershire sauce to cheese spread.

Fructose rapidly leads to weight gain and abdominal obesity, along with elevated uric acid, which leads to chronic, low-level inflammation in your body. It will also interfere with leptin, as fructose tricks your body into gaining weight by fooling your metabolism, as it turns off your body's appetite-control system.

Fructose does not appropriately stimulate insulin, which in turn does not suppress ghrelin (the "hunger hormone") and doesn't stimulate leptin (the "satiety hormone"), which together result in your eating more and developing insulin and leptin resistance.

As a standard recommendation, I strongly advise keeping your TOTAL fructose consumption below 25 grams per day.

But for most people it would also be wise to limit your fructose from fruit to 15 grams or less, as you're virtually guaranteed to consume "hidden" sources of fructose if you drink beverages other than water and eat processed food. Remember, the average 12-ounce can of soda contains 40 grams of sugar, at least half of which is fructose, so one can of soda ALONE would exceed your daily allotment.

For more tips on how to eat healthy to avoid gaining visceral fat and help eliminate belly fat you already have, see my comprehensive nutrition plan. Additionally, you should be sure you're getting plenty of animal-based omega-3 fats, such as those from krill oil, as they are phenomenal for your heart.

Exercise can melt away your belly fat

Exercise not only lowers inflammation in your body, it is also one of the best weapons to fight visceral fat, but it is NOT magic and you must abide by the sugar and grain restriction if you want to reduce your body fat. About 80% of your ability to achieve an ideal body fat will be related to your food choices NOT your exercises. However if you are choosing the right foods exercise is a shockingly effective tool.

Remember, you can be thin, underweight even, and still have dangerous visceral fat around your organs. If you are thin, but rarely exercise, this may be you. And if you have a beer belly or a lot of fat around your midsection, you can also bet on the fact that you're holding on to visceral fat.

According to one study, those who did not exercise gained a substantial amount of visceral fat (8.6 percent) in six months whereas those participating in vigorous-intensity exercise lost about 7 percent of both subcutaneous and visceral fat.

There are two types of exercise I most highly recommend for reducing visceral fat:

Three more tips for a healthy heart

Heart disease is one of the easiest diseases to prevent -- if you are proactive about it. Along with reducing your belly fat using the diet and exercise tips described above, the following items are heart-healthy steps that virtually everyone can benefit from.