What Should I Weigh?
There is no single question or formula to calculate weight. One could look at percentage of body fat, fat free mass, height, and weight tables that were calculated in the 1950’s by Metropolitan Life Insurance Company. However, we are a country obsessed with numbers. Although not necessarily my favorite calculation, the calculation that is becoming universal from physician charts, insurance perspectives, military calculations, NIH data, and from a general health comparison perspective is the body mass index or BMI.
The BMI has shortcomings because of the calculation bias. Muscular people have deceptively high BMI’s; patients with long legs have falsely low BMI’s. However, many state medical boards are requiring BMI’s for legal reasons. We therefore make the best of it. The BMI can give you a ballpark figure of where you are and where you need to go. The BMI numbers I use are 25 or less is preferably, over 27 if overweight and over 30 is obese. BMI’s also go to “triple x sizes”. Greater than 40 is severely obese, greater than 50 is morbidly obese, and so on.
As a general rule, one BMI is roughly six pounds. With shorter individuals, it is less and with very tall individuals it is slightly more than six. Over time, we have learned to work these BMI numbers to our advantage. Once we initially calculate an individual’s BMI initially, we can do the following:
- Group the patients into their weight category. For instance, a 268 pound woman at 5’7” roughly has a BMI of 42. This lets her know that she is severely obese. Remember, preferable 25-27, overweight is 30 or greater, greater than 40 is severely obese, and 50 or greater is morbidly obese. Just being grouped into a severely obese category can be degrading and can hopefully motivate a patient to lose weight. From a personal perspective, it takes pressure off of the physician. I will politely say, “It’s not what I think, it’s just what the chart says”.
- Give you the hurdles to jump through to reach your goal. Using the “one BMI unit equals six pounds”, I can calculate in my head how much weight loss is needed to drop to lower BMI’s. To lose from a BMI of 42 to a BMI of 40 will require a weight loss of 12 pounds. To lose from a BMI of 40 to a BMI of 30 will require a weight loss of 60 pounds. From the original BMI of 42, to reach the ideal BMI of 25 would require the loss of 17 BMI units or approximately 142 pounds. This goal is absolutely possible!!!!!
This brings up two important points:
- My non-negotiable comment for women is this: “You cannot be healthy over 200 pounds.”
- Under 196 pounds is no longer obese. Again, this is very motivational.
Now back to what I mentioned previously, there is no one exact calculation. It really depends on the individual and more importantly, where the individual starts. For example, if a person presents with an initial BMI of 58, 350 pounds, I would be happy to reach of BMI of 30.
Remember the calculations? 58 BMI units – 30 BMI units = 18 BMI units. 18 BMI units x 6 lbs/BMI unit = 108 lbs.
Although a BMI of 25 is preferable, a BMI of 30 is acceptable after a 108 pound weight loss.
On the other hand, I have had patients with lower BMI’s who would benefit from being much less than 25. Patients with long legs with a BMI of 26 have their abdomen over their belt would greatly benefit with a BMI of 22. This represents an additional 24 pound weight loss. Interestingly, as of January 2011, “muffin top” is now included in the dictionary.
Now with all the numbers out of the way, remember that it is more important how you feel, fit in your clothes, and most importantly, how you feel about yourself.