Thursday, September 19, 2013

Why counting calories doesn't work

The food issue of Scientific American came out yesterday and they have a pretty cool spread on how and why counting calories doesn't work.  Below is a video going over some of the very basic science.

Why Calorie Counts are Wrong

As a strength and wellness coach I have seen the argument, time and time again, that in order to lose weight people need to eat less and exercise more.  This quantitative approach fails on so many levels that I thought it prudent to write a blog article on why it fails.  Before we delve in to the specific reasons why, I think it's important to first set down a framework for how the human body works.  From there I will go over why counting calories doesn't work and what you should focus on to lose weight effectively.

From hormones to genes to environmental signals

When you look at how the body works, you can see fairly easily how counting calories and focusing on burning them fails.  Systems within your body talk to one another via hormones, also known as chemical messengers.  For example, when you consume a meal, nutrients get digested and eventually enter your bloodstream.  These nutrients, in turn, cause the secretion of hormones to help utilize and store these nutrients.  When you exercise, hormones are also released that help dictate the fuel you use.  In fact, there isn't a time in the day when you are not secreting some level of many hormones.  However, while your hormones are affecting how you feel, how much energy you have, and whether you are actively using energy or storing it for later use; what you do throughout the day will also affect those hormones.

We do not need to discuss the biology of this in great depth to grasp a very simple concept.  What causes the secretion of hormones is genes.  In fact, every biological process occurs via genes.  A perfect example is alcohol.  In order to make alcohol you need water, sugar, and yeast.  The water is the medium in which the yeast convert sugar in to alcohol.  The yeast do this because they contain genes that direct the processes that cause the fermentation of sugar in to alcohol and water is required for this process.  If the genes weren't there, the yeast would do nothing.  If the water and sugar weren't there, the genes would do nothing.  If you put the yeast in a pail of gasoline and oil it would do nothing.  Genes are a set of instruction for what an organism will do under certain environmental conditions, or signals.  If the proper signals are not sent to the genes, they do nothing.

In much the same way, you burn fat under the proper environmental signals.  This is largely dictated by the hormonal environment within your body.  Making it an even more complex situation, we burn fat and glucose through separate, intertwined processes.  At no time are you ever burning 100% fat or 100% carbohydrate.  Even if you ate no carbohydrates, your body can still make glucose which is how carbohdyrates enter the glycolytic(carbohydrate burning) energy systems anyway.   If you ate no fat you would simply use body fat to fuel fat dependent energy systems.

The energy system that is predominantly used is largely dependent on the environmental signals you send, which are dictated by lifestyle factors including sleep, stress, exercise, diet, and how each affects your hormonal profile.  Ignore these factors and not only will you not burn fat, you will set yourself up for failure by producing a hormonal environment primed to drive your appetite through the roof and store as much of the energy you consume as possible.  So while you are essentially a machine, you are far too complex of a machine to be broken down in to a simple, archaic energy in/energy out system.

A good analogy for this is a hybrid car.  The calories in vs calories out mentality is that if the car won't move, all you need to do is put more fuel in to it, regardless of type.  However, if the car won't move because it is out of gasoline, you cannot pour electricity in to the gasoline motor because it cannot use electricity as it's energy source.

Appetite and food reward

Another reason that calories in vs calories out doesn't work is because it fails to address appetite.  Appetite is dictated by hormones as well as something called food reward which directly impacts hormone secretion.  The food reward system is very complex but involves the same processes and areas of the brain that drug addiction affects.  Basically, certain foods hit the reward center of your brain hard and generate a sense of pleasure we like.  This means that, over time, we will actively seek out these foods, especially when we are hungry.

Removing these foods for an extended period of time not only reduces your craving for them, it helps put you in a better hormonal environment to burn fat.  Frequent consumption of these foods wrecks your metabolism by negatively affecting your cells' sensitivity to insulin and leptin, two very important hormones.  If it were simply a matter of calories this shouldn't be an issue, but it's a big one.  It's also why once you pop you can't stop and the primary reason you can't eat only one.

It's all in the genes, and most of them aren't yours

Now that we have a thorough understanding behind the general concepts of how genes impact biology, it becomes important to realize that most of the genes responsible for the biology going on in your body right now do not belong to you.  Most people have heard of their gut bacteria, but I don't think they truly understand the scope of how important these little guys are.  From a shear numbers standpoint, the bacteria in your gut outnumber the cells of your body 10 to 1.  This not only means we are only 10% human, it also means that the amount of genetic material contained within the bacteria in our gut outnumbers that within our cells by a factor of 300(1).

If you buy in to the importance of genes for human health, it isn't too far of a stretch to realize that our gut bacteria should be a main concern.  These bacteria help us in many ways by helping train and control the immune system, manufacturing nutrients, transporting ions, helping heal intestinal damage, and this is merely the tip of the iceberg.  There also appears to be a line of communication between the brain and the gut.  This is a 2 way line of communication that appears to be through the vagus nerve(2), a part of the autonomic nervous system which regulates minor things like respiration, heart rate, and blood pressure. 

Changes in gut bacteria have been attributed to so many diseases that one may be suspicious of all the things healing the gut could potentially help.  People with autism, adhd, anxiety/depression, Type 2 diabetes, heart disease, you name it.  With regard to obesity, there is a clear relationship.  While there are more than 10,000 different strains of bacteria in your gut, most of that bacteria belongs to 10 species.  Of those 10 species, the ones that appear to be the most important to human health are bacteroidetes, firmicutes, and bifidobateria.

Specifically, with regard to obesity, there appears to be two strains of bacteria that are consistently different between obese and lean people, bacteroidetes and firmicutes.  Obese people tend to have fewer bacteroidetes and more firmicutes than lean individuals.  This relationship is so powerful that in mice, when mice with sterile guts are given the bacteria from lean humans they remain lean and when they are given the bacteria from obese humans they become obese.  If you place these mice together in cages and give them the proper diet the obese mice become lean(3) because the obese mice eat the lean mice's bacteria(aka poo).

Many other studies have shown that swapping the gut bacteria between lean and obese mice causes the mice to take on the form of the mouse whose gut bacteria they were given.  In all of these experiments, calories were kept exactly the same.  One of the primary factors noted for this phenomenon is that the gut bacteria in obese mice extract more energy from food which provides an energy surplus to the host.  This means that while the calorie count is the same, the gut bacteria liberate more energy for the host which in turn causes more calories to be absorbed.

Building a proper microbiome

For the most part, the types of bacteria found in your gut are determined in your first few years.  Whether you were born vaginally or via C-section, whether you were breast or formula fed, and whether you were kept in a completely sterile environment or had frequent exposure to dirt and bacteria when you were a baby will dictate the types of bacteria in your gut.  Once your gut is populated, the proportion of each strain of bacteria is largely dictated by diet.  In the study on mice that were given human gut bacteria, a diet high in fruits and vegetables and low in saturated fat led to the more desirable lean gut bacteria while a diet low in fruits and vegetables and high in saturated fat led to the obese gut bacteria.  From the research it appears that the more desirable gut bacteria tend to feast on the fiber and polyphenols found in fruits and veggies(4, 5).

I have not seen any evidence that suggests that saturated fat is implicated in altering the gut bacteria in obese people.  While it is true that obese people tend to eat more saturated fat, they also tend to eat more processed foods high in sugar and avoid fruits and vegetables.  One of the more troubling developments over the past 40 years is that people avoided saturated fat and swapped in processed, high sugar foods which do have a damaging impact on gut bacteria composition.  This scenario has played out the way it would in a petri dish as bad bacteria crowd out good ones because the bad ones are fed and the good ones starved.


The video posted above goes over why calorie counts are wrong, but that is besides the point.  Even if they were accurate, focusing on calories in vs calories out will never be a successful way for people to deal with weight loss.  If more people focused on what they should eat rather than how much, they would be in a much better place right now in terms of health as well as proper weight maintenance.  The research has been pointing in this direction for quite some time now, but by the time it reaches clinics and fitness professionals it may be too late for some.

Being a fitness professional, I should be towing this line if I was doing what's right for my pocket book.  If I want to do what's right for my clients, I will help them alter their lifestyle in a way that will foster genetic expression that is optimal for weight loss.  This doesn't involve buying supplements, starving yourself, and exercising with me 6 days a week.  It involves eating the proper foods and staying off their butts more than sitting on them, something I discuss here.  Exercise is merely icing on the cake.