Ketosis Part II: Regulation

Now that we have a good idea of what ketone bodies are, and how they start to get formed and where I think it is time to loot at the regulation of the process.  I think what has been really interesting to me in researching this topic is that I expected to find some sort of “master switch” for ketosis.  What I mean by that is I figured that something would happen that would turn on ketosis, and as such you are either in ketosis or out of ketosis.  However, as we saw in the last article everyone produces small amounts of ketones at rest, and ketosis is physiologic process that just happens when the substrates are available and are not being used for other processes. 

There are two main types of regulators for ketogenesis, and while they may seem very different to some people, I think they are rather similar.  It all depends on what energy our body is using, and in what amounts.  Ketogenesis can be controlled either through physiologic processes or through enzymatic processes.  We will start with the physiologic ways that ketosis is controlled, and then go to the enzymatic/hormonal ways, since those are probably a bit more complicated.

When we talk about physiologic processes that induce ketosis we are talking about what is going on in our body to make it start naturally producing ketone bodies.  There are three main ways this happens, and a fourth little trick people use to jump start the process (any guesses now what that is?).  The three ways are: starvation/fasting, prolonged exercise, and a low carb/high fat diet.  Let’s take a look at each of these in turn.

Ketosis Part I

Everyone has heard of it, some of you may love it, some of you may hate it.  While most people know the general facts about ketosis, I have been hearing a lot about it lately, and it seems like every time you talk to someone different about it they have a different opinion on it.  Some people think it is the ideal state for our bodies to be in, while some think of it like the plague, and something to be avoided at all costs. Well, I am going to try and clear up some of the confusion on the matter.  This won’t be an easy, or small task, so bear with me as I try and go through all the facts to make sure I get everything right.   As a general game plan I think a good place to start will be what are ketone bodies, how are they made, how are they transported and what tissues can use them.  Then we can move into their metabolism, uses, and long term ketosis.  Other topics will come up along the way, but that is what the information I hope to synthesize here for you.  In order to transmit all of this information we will have to get fairly technical, and I will have some pretty complicated figures presented, but hopefully I can pull out the main points of them for everyone.  Well, let’s get started.

Cornerstone #3: Eating to satiety

The first two cornerstones have focused on what to eat and when to eat.  Now we focus on the obvious next question: How much to eat?  As I previously talked about our body has an incredible ability to regulate its energy intake all by itself.  Without conscience effort of what, and when to eat, humans should be able to regulate their energy balance on a completely unconscious level.  This process is regulated in many ways throughout the body, but I think one of the key ways to maintain this balance is to always eat to satiety, or fullness.

Benefits of Intermittent Fasting

We are going to take a quick break from our regularly scheduled programming because I just stumbled upon this new study from FASEB. The study is titled "Timed high-fat diet resets circadian metabolism and prevents obesity".  The wording "Timed high-fat diets"  is kind of confusing, but if you read the paper what they did was an intermittent fasting protocol.  Rats were separated into one of 4 different groups: an ad libitum low-fat diet (AL-LF), an ad libitum high-fat diet (AL-HF), a restricted feeding low-fat diet (RF-LF), or finally a restricted feeding high-fat diet (RF-HF).  The restricted feeding group was only allowed to eat for 4 hours/day, while the ad lib groups could eat whenever they want.

The results were pretty striking.  The RF-HF mice consumed the same amount of calories as the AL-LF mice, but had a 12% reduction in body weight compared to them.  Also, the RF-HF mice also had lower cholesterol levels, higher insulin sensitivity, and lower inflammatory markers than all the other study groups.  The RF-HF mice also showed signs of improved lipid oxidation, showing that the fat they consumed ended up being burned for energy, and not stored.  Not to mention that the HF diet was based on soybean oil and these are mice that are predisposed to become obese on a high-fat diet.  Finally you might think that these researchers were starving these mice on the RF protocols, but the RF-HF mice had lower ghrelin, indicating a higher degree of satiety.

A lot of people think that the benefits of intermittent fasting come from reducing calorie intake due to the small eating window.  However, this study shows that even if you eat the same amount of food, and pretty crappy food at that, eating in an IF way can help you improve your health.  I have found that I naturally tend to eat in a restricted feeding type way, with most of my eating happening a 6 to 8 hour window just naturally.  I just thought this was a pretty interesting study and showed some of the very powerful benefits of IF protocols for health.

Cornerstone #2: Eating when Hungry

Our bodies are an incredible thing.  They are able to control so many different processes and chemical levels all inside a contained system with no external support.  This type of internal regulation is known as homeostasis, and allows us to do things like always keep a constant temperature, ensure our blood pressure doesn’t get too high, and even keep a proper pH balance within the body.  The body even has its own homeostatic controls for energy balance, and uses these to help control how much energy goes in and out.  Now, I assume most of you are asking yourself that if the body can internally control things like blood pressure and energy balance, why are there so many people with hypertension and obesity?  Well, these homeostatic controls can break down, especially in the perfect storm of the Standard American Diet (SAD). 

This internal control of energy is nice and all, but how can that help us?  Well, I think it leads us to my 2^nd cornerstone for health: Eating only when hungry.  Do you think our hunter-gatherer ancestors stopped at noon to eat lunch just because it was lunch time?  No way!  They ate when they needed to.  Obviously this eating strategy is starting to look like it’s on to something from an evolutionary perspective, but lets take a look at what the current science says about this.

Cornerstone #1: Eating a whole food diet

While doing some research for another post I came across an interesting article by Spreadbury about how the type of carbohydrate differs in an ancestral diet compared to a western diet.  The article, “Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity.” was just published the other month, and is available for free online.

The article is really great and is well worth the read.  He starts off by explaining the discord between much of the data for macronutrient ratios and obesity.  While both high fat and high carbohydrate diets have been implicated in the development of obesity in western society, these diets result in very healthy people when consumed in a “traditional” culture.  Since these diets only promote obesity in a western culture, there must be some other factor that makes these diets cause obesity, rather than the carb/fat ratios themselves.

Brain Fuels

If you ask many people what the primary fuel for your brain is they will most likely tell you that it is glucose.  In fact many sources used to say that the brain could ONLY use glucose as a fuel.  However, it has been known for some time that ketones are more efficient fuel source for our brains.  In fact this article says that ketogenic diets have been used as a treatment for epilepsy since the 1920’s!  And now, an even more efficient fuel is being talked about: Lactate.  Peter from Hyperlipid has a good write up about a paper that talks about the brain using lactate, and why he thinks it is such a good fuel.

This is all well and good, I am all for feeding my brain the most efficient fuels.  If we evolved primarily to support such big and “expensive” (energy consumption-wise) brains this would seem a very important thing to do to maintain good overall health.  However, after reading all this I am left wondering: How am I supposed to get all this lactate to feed my brain?  I can’t eat lactate. Also, with all these fuels for our brain, is there an optimal ratio of fuels?  Let’s take a look.

Trying new things

I think that one of the most rewarding parts of switching over to an ancestral lifestyle is that you are always willing to try new things, and things that once bothered you don’t anymore.  I am sure there is a more scientific explanation for this, but it is just something I have noticed.

When I was younger I HATED trying new foods.  If it wasn’t something I was comfortable with, I didn’t touch it.  In fact, my family was known to create chants to help me finish off certain foods at the dinner table (Peas and cream corn come to mind).  However, after living an ancestral lifestyle for the better part of 3 years now I have no problems trying new foods.  I went from being the least likely person to try new foods, to the most welcoming of the new experiences. 

I think this also holds true with other things in life.  Those who follow an ancestral lifestyle are just more willing to do say yes to new things.  We are more likely to go with the flow.  Other lifestyles are rigidly structured by meal times, work times, travel times, and all other routines.  But, when you adopt the ancestral lifestyle you throw a lot of that out the window and just start doing!  You also make more room for play, and have structured stress reduction techniques.  Is there a link between stress reduction and a willingness to try new things?  Most likely, especially because the kind of stress we are most accustomed to is the worrying, anxious feeling we get in an out of the ordinary situation.

I think this all ties together through play and fun.  Trying new things is exhilarating and gives you a rush and satisfied feeling.  This also is pretty similar to Mark Sisson’s recent posts on IE. 

So, with that let’s all go out and try something new today!

A human need for fiber?

Well after attending AHS 2012 the other week I came home with more questions then I could have imagined going into it.  All of the presentations were fantastic, however the safe starches panel seems to be the most talked about.  This was very interesting, as it seemed like the panelists covered almost the entire spectrum of a carbohydrate intake continuum.  Another point that was brought up was the need for dietary fiber, and, being somewhat unsure about this topic, I decided to dig a little further into it.