In general, I think a lot about weight. As a girl growing up near a beach in Los Angeles, weight was constantly on my mind. Now, as an interventional and preventive cardiologist, I routinely talk with patients about their weight during clinic visits. It’s an extremely sensitive issue for many people. Often, people have been shamed about their weight, and it may be intricately bound to our sense of self-worth. But leaving that complicated psychological aspect of the weight discussion for another day, is there such a thing as an ideal cardiovascular weight?
First and foremost, weight is not just a number on a scale. Women more than men think about the number on the scale; often, we fixate on a “magic number.” But the reality of optimal, ideal weight is much more complex.
One measurement that has been discussed routinely is body mass index, or BMI, which takes into account our height and weight. By this formula, BMI of 18.5 to 24.9 is ideal, 25 to 29.9 is overweight and above 30 is considered obese. Created about 200 years ago to estimate obesity, BMI still works well for most people. But it isn’t perfect. It makes no adjustment for relative proportions of muscle, fat and bone in the body. So in a very fit person who is muscular and has low body fat, it will overestimate his or her BMI.
There have been calls to use waist circumference or waist-to-hip ratio to better predict risk. This, together with BMI, appears to be a better estimator of cardiovascular risk. The reason may have to do with visceral — inside — versus subcutaneous — outside — abdominal fat deposition. This was recently validated in an Annals of Internal Medicine paper using National Health and Nutrition Examination Survey data from 15,000 patients over 14 years.
Waist is measured at the top of the hip bone, and the hips are measured at the greatest circumference. A ratio greater than 0.89 for men and greater than 0.80 for women is considered obese. Even for normal BMI patients, having belly fat — as measured by waist-to-hip ratio — increased their risk of dying. The fat deposited inside your organs, like the liver, greatly increases the risk of dying of cardiovascular disease, most likely due to inflammation. We used to think fat was inert. Now we know that fat causes inflammation that can lead to cardiovascular disease, such as heart attack and stroke.
So what does all this mean, especially amid all the confusing messages about weight and diet? It means just losing weight or focusing on the magic number isn’t good if we aren’t fit. It means that if you have a normal BMI but don’t exercise and have belly fat, that’s not a good thing. If we only lose weight, we often lose muscle mass. So the goal should not be the magic number, but instead should include being fit and having a reasonable BMI.
The truth about losing weight and keeping pounds off is complex. But it can be summarized by the following: Losing weight is always much easier than maintaining weight loss. Studies show that exercise is the key to maintaining weight loss.
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Is There Such a Thing As An Ideal Cardiovascular Weight? originally appeared on usnews.com
