The Metabolism Myth

Metabolism might be the least understood and most misused health topics that exists. By misused, I mean that many people blame their “slow” metabolism for being overweight, or a “fast” metabolism for being skinny. While there are some genetic factors involved, these kind of statements about the metabolism couldn’t be further from the truth.

Your metabolism is primarily based on the amount of Fat Free Mass (FFM) you have. This only differs slightly from Lean Body Mass (LBM) in that LBM also includes some essential fat that is mostly around and in your organs.

If you have had a an accurate body composition test done then your Basal Metabolic Rate with be an amount closely related to the amount of your Lean Body Mass percentage. Basically this means that the more muscle mass you have the higher your metabolic rate will be in relation to someone your same weight, height, and gender.

Before we move ahead let’s go back and examine what your metabolism really is, before we worry how high or low it is, and if you can change it.

The majority of your metabolism revolves around simply staying alive. Your organs use up anywhere from 60-75% of the daily energy you consume. Men generally have bigger organs than women which accounts for their slightly higher metabolic rate. That and the fact that men generally carry more muscle mass than woman. Your body also has to stay within an optimal temperature range to function well. These factors make up the vast majority of what we call a metabolic rate.

When we say someone has a fast or slow metabolism what we are really saying is that “the devil is in the details.” Does this person have more or less muscle mass? Do they exercise more than we do? Do they eat more or less than we do? What a minute. I think what we are really saying is that they have a faster or slower metabolism than us. Doesn’t it make sense that a 220 pound man will have a higher metabolism than a 120 pound woman? Of course that makes sense, but we really don’t think about that when we are explaining away our own thinness or thickness.

I am going to go out on a limb here and say that your metabolic rate has very little, if any, relation to how fat you are. In fact, the fatter you are the more likely it is that you have a higher metabolism than you should have. How can that be possible? Every pound of body weight you have requires some maintenance. That maintenance costs some energy. Every additional bit of energy cost your body has increases your metabolic rate. Now muscle mass burns somewhere around eight times as many calories as fat mass does, but each bit of mass has a cost nonetheless.

So if metabolism has nothing to do with how fat someone is, then what is the real reason a person becomes fat.


But let me digress for a moment and also mention that each bit of food you digest has a cost to it. Meaning that a bit of food could amount to 200 calories of energy, but cost you 30 calories to digest it, leaving you with 170 calories left for future use. Some foods have a higher energy cost than others. For instance, celery is known to have a negative net cost to it. Meaning that the cost to digest celery is more than the calories it provides you in return.

So back to appetite…

Generally speaking, when you eat more calories than you use up in a given day you gain weight. This is why people think they are fat because their metabolisms are low. They blame calorie output for their fatness, instead of calorie input.

Going back to celery example. Certain foods such as celery that are high in fiber help you lose weight and keep the fat off. Why? Because they cost a lot of energy to digest and give you little energy in return. Highly processed foods are super easy to digest and give you a ton of energy in return. See the pattern? Carbohydrates are easier to digest and give you a lot of energy in return. Fat is hard and slow to digest, but gives you a ton of energy in return. Protein is very hard to digest, and gives you little energy in return, specifically because protein is used as a building block rather than an energy source in many areas of the body.

All that to say that there are other factors to consider in how fat or skinny you are than just the rate of your metabolism.

This is our 24th challenge in The Personal Health Challenge Series…


  1. I ran a 31 Day Healthy Living Challenge back in 2010 and really enjoyed it. What I think about healthy body is totally simple. Just enjoy the food. Then burn it off by exercising. It works easily for me.