Saturday, February 12, 2011

Let's make Grok Fat

So a while ago, my buddy D2 Primal posed to me a challenge. If exercise does not make you lose weight, how do you explain to someone looking at the before after pictures at our gym (we go to a gym that is a part of a large chain I'll call Silver's to hide the real identity) that it was not the exercise that made them lose weight (and specifically fat).

So I got to thinking about this and decided to write a series of posts to explain, first how we get fat, then how conventional wisdom fails us in the advice it gives us on how we get rid of the fat, and finally how the low carb/primal lifestyle can help us to get rid of the fat and get back to being healthy.

I will say now that I will not be as eloquent as Gary Taubes or as technical as Hyperlipid. These guys are very deep thinkers who have a lot of knowledge and experience behind what they say. This will be more of my attempt to organize what I believe is happening within our bodies.

I have decided to use Mark Sisson's character Grok to illustrate the process of getting fat and getting back to health. For those of you who don't know about Grok, I'll give a small introduction but I highly recommend Mr. Sisson's excellent book Primal Blueprint as a more complete picture.

Grok is the personification of what humans evolved into during the majority of our existence on Earth up to about 10,000 years ago when agriculture was introduced into the equation. He eats what we evolved to eat, which is largely animal products with some fruits and vegetables. He does not avoid grains and sugars because, they didn't exist. He didn't go to the gym for the same reason. The exercise he did get was from walking a lot, doing intense work for brief periods of time to bring down prey or escape becoming prey (not the equivalent of an hour of cardio but more like wind sprints or tabatas), and from play. His species (and therefore us) evolved through natural selection to thrive off of this type of lifestyle.

Now, I'm a computer guy so I tend to like numbers and equations. So let's say that Grok eats about 2000 calories a day (I don't know if that is realistic but it's round) and expends about 2000 calories a day. We know he expends this much because he is weight stable and therefore is burning and excreting what he brings in.

So how do we make Grok fat? Well, let's transport him from his life 10,000 years ago to the present day. This will give him access to grains, sugars and foods he never imagined eating. So Grok starts eating sugar and refined carbs (rice, white bread, etc). He replaces some of the animal products he used to eat (bison liver, etc) with this new tasty food. What happens in his body? Well, as a result of the sugar, two things happen since sugar is made up of two things: fructose and glucose. The fructose goes to his liver and is turned into fatty acids, the glucose goes into the blood stream and raises blood sugar levels. The pancreas responds to the higher levels of blood sugars by producing insulin. The insulin does a few things, first it chokes off the supply of fatty acids into the blood stream from the fat cells. It does this to get the body to burn off the blood sugar since high levels of blood sugar can be toxic. It also causes cells in the liver, muscles and fat tissue to take up the sugar in the blood to lower the blood sugar levels.

Now if the fructose dose Grok gets is high enough, the fructose puts such a load on the liver that it causes the liver to become insulin resistant which means the pancreas will have to produce even more insulin to get the blood sugars out of the system. As insulin levels consistently go up in reaction to the intake of sugar and refined carbohydrate , eventually muscle cells become insulin resistant. This leaves fat cells to take in the blood sugar. Fat cells can become insulin resistant too but they are usually the last ones that do. Eventually Grok's body has consistently high levels of insulin in his system which means the calories that he does takes in (plus the carbs that he takes in) gets partitioned more to fat storage than to burning. Why is this? Because the insulin enhances the process of fat storage and simultaneously chokes off the release of fatty acids from fat storage to be used as energy.

So what does this do to Grok at a macro level? Well, he is eating 2000 calories a day and his body still wants to burn 2000 calories a day but let's say, the result of the elevated insulin levels is that 500 calories of his intake is put into fat storage and blocked from being released (imagine putting a kink in a garden hose and slowing down the release of the fatty acids). So his body has only 1500 calories to burn. Two things can happen at this stage. His body can react by slowing down his metabolism (keeping him tired and listless, cooling his body temperature, etc) to match the 500 calorie deficit, or (and maybe as a result) his body will make him hungry to eat more. So Grok eats another 500 calories. And 100 calories go into storage and 400 more calories are available to burn. Still a deficit of 100 calories between what his body wants to burn and what he has available.

Keep in mind, at this stage Grok is not aware of his body changing, he is just reacting to hormonal signals that are telling him to eat or slow down his activity.

Let's say it now takes 2600 calories a day to allow Grok to keep his lifestyle going. 2000 calories must be available to burn, but because what he is eating is forcing more fat into storage and (maybe more correctly) slowing down or blocking the release of the fatty acids from storage, he is storing 600 calories a day. This would result (if nutritionists are to be believed) in about a pound of weight gain a week. Let's say that continues for a year and he gains 52 pounds. Eventually, the fat cells are going to get so full, insulin cannot choke off the supply completely and some fatty acids will overcome the effect and get into the blood stream to be used for energy. I'm sure this is overly simplistic, but what I'm getting to is that the body will eventually reach an equilibrium where the energy coming in equals the energy being expended and excreted and weight will become stable. This maybe at 52 pounds of extra weight, it could be at 200 or 300. It all depends on genetics, environment and other factors.

So this is how Grok got fat. Now one thing to notice here, it's not because he was eating that well marbled rib steak. It was because he ate that steak with a white potato and followed it up with that piece of cake. Yes, fat played a factor but only because it was accompanied by food that caused insulin resistance and blood sugar spikes and both resulted in elevated levels of insulin which signaled to Grok's fat stores that fatty acids should not be released because the body needed to get rid of blood sugar. Even after the blood sugar dropped down to a reasonable level, the level of insulin in Grok's system remained high (due to the insulin resistance) and since the fat stores would not release their fat, Grok felt hungry and tired. He, as a result, slowed down his activity and probably had a snack.

This is very simplistic and ignores a whole lot of other interactions that go on, but as far as I can tell, this is the primary reason we get fat. If I have made any errors, PLEASE comment with a correction. If you have a reference that will help my understanding, I'd like that too!

The next part will be what happens when Grok looks in a mirror and starts wondering how he let himself go.

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