Doc, Is My Metabolism Slow?
by Michael Bilof, MD, FACS, FASMBS

As you might imagine (given my profession), I spend a great deal of time talking to patients about weight, weight loss, calories, and why sometimes it seems so darn hard to lose those last 10 (or 20, or 30, or you name it) pounds...

Such discussions often lead to questions about metabolism. Many patients think they have "slow metabolism" or have been told by someone who seemed knowledgeable that they have a slow metabolism. Many patients think this is why they have a weight problem or why they have trouble losing weight.

Most patients actually have a pretty normal metabolism. Of course, you should have your thyroid checked out (very easy to do with a simple blood test) as an underactive thyroid can give you a slow metabolism. If your thyroid is underactive, it is very easy to treat with a medicine you take once per day. So, let's assume your metabolism is "normal." What does that actually mean? Is there anything you can do to increase it? And what does that have to do with losing the last 10, 20, or 30 pounds?

First of all, everyone's metabolism is a little different. An easy way to understand this is: We are not all the same height and so we don't all have the exact same metabolism, but we are all in a pretty close range. If you want to get an idea of what yours is, simply type "basal metabolic rate" into Google's search engine and it will take you to any number of sites that can give you an idea of what your metabolism is.

If you want to lose weight, you have to make sure that the number of calories you consume every day is less than your metabolic rate, we call that a "caloric deficit." When the caloric deficit equals 3500 calories, you lose about 1 pound. So, if you have a caloric deficit of 500 calories per day, you will lose one pound per week. (500 calories/day x 7 days = 3500 calories, which equals one pound weight loss.)

Now, two questions I frequently get from my female patients are: Why is it so much easier for my husband to lose weight? Why was it so much easier to lose weight when I was 20 years old?

The answer to both questions is really the same: muscle mass! The more muscle a person has the higher the metabolism. So, for instance, if there is a 20-year-old and a 40-year-old who are the exact same height and weight, the 20-year-old will have more muscle mass. Similarly, if we have a man and a woman of the same age, height, and weight the man will likely have more muscle mass (sorry ladies, it's true!). Since muscle is what the body uses to do work, it makes sense that the more muscle tissue a person has the higher the metabolism.

If you are following me here, than I hope you figured out the punch line: If you want to increase your metabolism, how do you do it? You need to increase your muscle mass. And how do we increase muscle mass? Exercise! This is why exercise is so important. Exercise helps you lose weight in the first place, and while you are exercising, you build the muscle mass that will increase your metabolism, which then keeps the weight off!

Now, many patients tell me that it feels like it gets harder to lose weight once they've already lost a bunch of weight... don't worry, you're not crazy. There is a good reason for this, which I think is pretty easy to understand, but to understand it we first have to talk about one of my favorite topics... cars! Pop Quiz: Which uses more gas, a 6000 pound Hummer or a 3000 pound Camry? Pretty simple, right? The Hummer, of course.

Now, let's compare two people, one weighs 350 pounds and one weighs 200 pounds. If both people spend 30 minutes walking, which person will burn more calories? Since the 350 pound person is moving around a bigger body, they will use more energy walking 30 minutes. Since they are burning more calories, they will lose weight faster. So, if you now weigh 200 pounds and you want to lose another 20, you will have to work a little harder than when you weighed 50 or 100 pounds more.

You will either have to work out for a longer period of time (say 45 minutes) or work out more intensely (by walking 3 miles in 30 minutes instead of 2 miles, for example). The good news is that once you've lost a bunch of weight, most people find that it is easier to work out for a longer period of time or do a more intense work out (or both), which will then continue the weight loss. And, of course, as we learned earlier, the exercise builds the muscle mass that then increases your metabolism, which is what keeps the weight off! Click here to visit Dr. Bilof’s OH profile.

Michael Bilof, MD, FACS, FASMBS is a Center of Excellence surgeon practicing in New Jersey.
He has been performing bariatric surgery exclusively for over eight years with offices
In Millburn and Bayville, New Jersey. For more information, please visit

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