Existential Fitness Part 3
I apologize for not posting this sooner, but I have had to think and rewrite to make sure that I do not step out of line professionally. I am not a nutritionist, and I am very careful not to present myself as such, but diet is an integral part of fitness and health and I cannot leave it out of the conversation just because I am not a certified nutritionist. So while I am not going to make specific dietary recommendations, I am going to explain what I understand about nutrition and its effects on health, and allow you, the reader to make your own conclusions. And on that note…
OK, by now I hope you have your body fat percentage because we need it to help figure out what you are going to be eating. But I am getting a little ahead of myself here.
Losing weight is really pretty simple in that it just requires you to take in fewer calories than you burn. Really, it is true. It is the law, specifically the first law of thermodynamics which states that energy cannot be created or destroyed. The calories (energy) that you take in must either be used (expended) or stored, and the body’s mechanism for storing that unused energy is fat. So clearly, if you take in more calories than you expend (“burn”) than your fat percentage will increase, but if you burn more than you consume, well the fat will have to be used to meet that energy requirement. OK, not exactly that simple, because the body is a magnificently complicated machine which has some rules that do not fit the “fuel burning” analogy as much as many people think. The laws of physics still apply, however, so I can guarantee that if you take in less calories than you burn, you will lose weight.
And yet “dieting” does not work, at least not for the long term for most people. How can that be? To answer that, we need to clarify the mathematical equation that involves calories and the body. The calories we consume are on one side of the equation, and the calories we burn are on the other, but the calories we burn are broken down into two major categories. The first is the calories burned through the physical activities such as running or walking or swimming, and people sort of understand these. The other is the calories that your body consumes just staying alive, just getting through the day.
This is referred to as the basal metabolic rate or BMR. And this BMR has a great effect on your weight loss and gain, as well as how much energy you have and how much you can do. And it is this latter part that stymies the well intentioned but poorly informed dieter. Let’s say that you have a BMR of 1800 calories per day. This would be the number of calories that you need to just stay the same weight you are, without any extra activities such as running or swimming or weight lifting. It would follow that if you took in less than this 1800 calories each day, you would lose weight, and you would if you took in 1500 calories or so. You would have a calorie deficit of 300 calories per day, and just as taking in more than you burn leads to fat gain, a deficit in calories will lead to weight loss. Notice that I said weight loss and not fat loss. While it is true that excess calories are stored as fat, it does not follow that the weight loss will be exclusively fat. The body can only store excess calories as fat, but it can and does use protein from lean muscle for energy, and this use of protein goes up as the calorie intake becomes more restricted. So, the dieter figures that if a 300 calorie deficit will lead to gradual weight loss, they can get faster weight loss (and everyone wants to lose it faster).
And so many of the diets on the market try to do just that by reducing the calories to extremely low levels, say 800 to 1000 calories per day. That works for the short term, because of the law of physics, you will lose weight, but much of that weight is going to be muscle. And that would work for the short term, in that you would lose weight, but what kind of weight? It matters, because if you lose muscle, and studies show that about a third of the weight lost in very low calorie diets is muscle, the loss of that muscle leads to a decrease in the basal metabolic rate.
So, just for argument’s sake, let’s say the BMR goes to 1500 calories. You are still losing weight but the longer you stay on the low calorie diet, the more muscle weight you are going to lose (along with fat weight), but the BMR will continue to decrease. The lower the BMR, the less energy you have because your system is shutting down to protect you from starving to death, and that is not a great way to feel, so eventually, you decide that you have lost enough weight and you can get off this damn diet. Right? Well, no, because you have changed your BMR to a lower number, and if you go back to the 1800 calories/day that was your old caloric requirement, you will start gaining weight again. And do it again, and the same thing happens again. And that is the problem with the yo-yo dieting that people talk about. We focus too much on weight loss, when what we really need to focus on fat loss. And to make sure we are losing fat and not just weight, we need to understand how the body utilizes food.
Rather than think about how many calories you are going to consume, lets take a closer look at the different components of food, and how they impact the body. Food basically breaks down into three macronutrient groups; protein, fats, and carbohydrates, and much has been written about how to structure your diet with different ratios of these components. Unfortunately, much of what has been written does not seem to take into account how the body uses and needs the various components, but focuses on short term diets and quick results.
Let’s look at protein first. Like carbohydrates and fats, proteins are made up of carbon, hydrogen and oxygen, but what differentiates protein from the other two is the presence of nitrogen. Proteins are made up of various amino acids (“amino” meaning to contain nitrogen) and the human body is made up of about 20 of these. While 11 of these can be synthesized by the body, 9 of them cannot and are referred to as essential proteins, and these must be acquired through diet. Actually, when we talk about protein requirements, we should be talking about amino acid requirements, because these are what the body uses to create the muscle and organs and other tissues that make up the machine or factory that is the body. “You are what you eat”, while a popular slogan with some merit, is not actually true. While many assume that we need animal proteins to build our muscles, that is not true, and vegetarian or even vegan diets can provide the required amino acids for the body to build the proteins that are the muscle and lean body tissue of the human body. It is true that animal proteins are an easier source of the amino acids, probably because their protein structure is more similar to ours than the protein structures found in plants. Some proteins do a better job of providing the amino acids than others. The higher the delivery of amino acids to the needs of the body, the higher the “protein quality”. It is critical that the body get all of the “essential” amino acids from the diet because the body cannot synthesize these and their absence will result in proteins not being created by the body.
Protein is essential to keep the body functioning, and the amount of protein is relatively specific and needs to be the first thing you calculate when figuring out your diet. Exactly how much protein you need is not something that I can recommend professionally, but I would offer this advice when looking at the various suggestions (and there are many that you can find in books and on the web)-go with a recommendation that is based on the lean body mass and activity level of the individual, and not merely on the weight. The lean body mass is the engine that requires the protein, not the excess fat that you are trying to get rid of, and so that should be the driving factor in your protein requirement. Another suggestion I would offer is to take the protein requirement that is based on your lean body weight and activity level, and bump it up by 15-20%.
My reasoning for this is that while you are trying to lose fat, you may be lowering your caloric intake, and under those circumstances, the body will use some of the protein as an energy source, so a little extra will serve to make sure that you have enough. If the body does not have enough, it will not be able to produce new muscle and you want that to help boost your BMR. That said, please do not do not take it to extremes and consume massive amounts of protein, as that will not serve you well. The body needs a certain amount to build and maintain muscle and lean tissue, and yes it will burn some as an energy source, but excess protein, like excess fat and excess carbohydrate is stored in the body as fat. And in order for the body to turn that excess protein into fat, it has to strip away and eliminate the nitrogen, which it does in the form of urea in urine, and excessive amounts of that could be damaging to the kidneys. If you have healthy kidneys, a little excess protein should not be a problem, and if you don’t have healthy kidneys, well you really should be talking with a doctor and not getting your information from an online blog!
The second part of this discussion will cover fats and carbohydrates, but that will have to wait until next week. For now, use your lean body mass and your activity level, and figure out a good protein requirement, and we will continue with this in the next installment.
Tim Beauchamp, CSCS, is a trainer and fitness consultant in Seattle.