Do I Really Have To Excercise?

The new patient (let’s call her Nancy) was not in any way unusual. She was fifty years-old and a life-long dieter. Five feet three inches tall, 189 pounds. Her body mass index (BMI), which is a persons' height divided by the square of their weight, was 32.

Normal BMIs are between 20 and 25. Between 25 and 30 is considered medically overweight, and obesity is defined as starting at a BMI of 30. 35 is the second stage of obesity. Morbid obesity (or as it is now politically correct to say, “extreme obesity”) begins with a BMI of 40. This last segment is the most rapidly growing segment of the
obesity epidemic.

Keep in mind that two thirds of the adults in this country are now either overweight or obese. I’ve come to think of a BMI of 32, while unhealthy, as garden variety obesity.

There was one thing about Nancy, however, that immediately jumped out, and that was her percentage of body fat. Our scale has a device called impedance plethmography, which means that it measures body fat percentage. A normal body fat percentage for a woman is less than 25% fat. Nancy was 52%. We routinely see patients with that degree of body fat, but usually they have BMIs that are much higher like over 40. I’m used to seeing a body fat in the 35 to 40% range for a BMI like Nancy.

I reviewed the nutritional history that we ask patients to fill out. It showed that she had lost and regained weight more times than she could count.

I asked her if she exercised regularly, either at the present time or in years past. She admitted that she had never exercised. Each time that she had lost weight in the past she had really deprived herself of food until she couldn’t stand it, then went back to her old ways and the weight rapidly returned.

Nancy’s body fat was so high because when she was starving herself to lose weight, she was losing a lot of that weight as protein, and when she was regaining it, and she was regaining it as fat. The protein that she was losing was coming out of her muscles and her internal organs (heart, liver, brain, etc); when she regained the weight those areas were filling up with fat.

Her subsequent physical exam and laboratory reports confirmed this. Her exam was really striking in her thighs. Both of her thighs had an hourglass shape; they tapered in at the middle and bowed out on both ends with squishy jelly-like material that was probably muscle completely interlaced with fat. Her blood work showed elevated liver enzymes, which is usually a sign of fat infiltrating the liver; a subsequent ultrasound of the liver confirmed this.

In short, Nancy was only modestly obese, but she was remarkably unfit and unhealthy.

A dirty little secret is that we can all lose weight without exercising. If we limit our calories to less than our bare needs, our bodies start breaking down tissues to supply the required energy, starting with our protein-laden muscles and organs. (Muscle can burn fat, but also weighs more on the scale.)

What people don’t tend to realize is that among other beneficial things exercise does, it preserves lean body mass. In other words, the weight you lose will be fat--which is the stuff we want to lose--and our muscles and internal organs will be preserved.

I love to exercise myself. I do it early in the morning and it lowers my stress levels for the rest of the day. I become much more tolerable to be around. If I don’t get a chance to do it, I get really crabby. My wife, kids, and my coworkers don’t want any part of me.

One of my kids is also pretty unbearable unless he is doing something physical, but my daughter, Jill, who also blogs here, hates to exercise unless properly motivated. Regrettably for those who hate to do it, it is pretty essential.

I always tell patients that I don’t have a pill labeled exercise. Even Bariatric Surgery patients are expected to exercise.

How much exercise should we do? And what type? That will be the subject of a future blog. The short answer--anything is better than nothing at all.