Below 18.5 underweight
18.5 to 24.9 ideal
25.0 to 29.9 overweight
30.0 and above obese
The problem with this method is that your weight consists of more than just the fat in your fat cells. You already know that water retention can add or subtract pounds to the scale. But did you know that your bones and muscles contribute to much of your weight? Bones are more dense than muscle and muscle is more dense than fat. A frail 83 year-old who has lost most of his muscle mass and has thinning bones may have a lower BMI than someone with large bones and well- developed muscles. In fact, years ago when we did a study among women smokers, we found to our astonishment that their BMIs put them in the ideal or even underweight category. But when they had a body scan of their bones and fat mass, it turned out that most of their weight was from fat; they had very little muscle and their bones were thin.
The best way of figuring out whether you are falling into an unhealthy weight because of your medication is to use a tape measure. These days something called the waist-hip ratio is being used to determine whether the size and location of your fat stores are normal or likely to lead to diabetes or cardiovascular disease. You don't need a scale for this measurement, and it will not be affected by whether you just drank a large glass of water. Stand in a relaxed pose and measure your waist at its smallest place, which is at your navel. Then measure your hips at their largest spot, which is over your buttocks. Divide your waist measurement by your hip measurement. A ratio above 0.8 for women and 0.95 for men is considered unhealthy and associated with obesity-related diseases.
The reason for concern if your ratio is higher than recommended is because fat stored over your abdomen has been found, in many studies, closely associated with those diseases that affect the quality of your life and may shorten it.
It would be a good idea to make baseline measurements before you start on your medication or if you are switching from one medicine to another. If you find the ratio going up, then bring it to the attention of your physician. Pop a tape measure in your purse or briefcase in case your doctor wants to verify the numbers on you (or check his or her own measurements).
Fortunately, you do not have to go off your medications to reduce the size of your waist. Simply eating therapeutic doses of carbohydrate that boost the appetite- suppressant effects of the brain chemical serotonin will allow you to eat less and not feel hungry. Add an exercise regiment and you can turn back into your formerly thin self.
