Showing posts with label High-fat diets. Show all posts
Showing posts with label High-fat diets. Show all posts

Wednesday, October 24, 2012

Ketosis VII: Practical recommendations


Well, here we are at our final Ketosis post!  It has been a long ride for all of us, and I hope you have learned as much as I have while researching the topic.

We have seen a lot of benefits of ketosis from helping lower triglycerides to helping with certain neurological conditions.  Now while all of these things sound great, how do we appropriately approach ketosis?  While many of us may want to try and be in ketosis at all times after seeing these benefits, and that it is a normal, physiologic process, I do think there are some reasons to not be in ketosis all the time, but I will cover those in a separate, later post, since I think they relate better to a different topic I have been thinking about lately.

So we know we have three main ways to get into ketosis: fasting, low-grade exercise, and high fat diets.  I think an appropriate ketosis-style diet is one that will combine all three of these into a cyclic approach, that way we make sure to leave ketosis for a little bit every now and then.  Also, as you will remember from my cornerstones of health posts I believe a system of HOW you eat it is very important to overall health, and we will also incorporate this system into our ketogenic protocol.

Sunday, October 14, 2012

Ketosis Part V: Medium-Chain Triglycerides


We have covered a lot of ground so far in looking over the literature on ketosis and ketogenesis.  We have seen what ketone bodies our body actually uses, and how they are regulated on many levels.

We already know that a high-fat diet is a great way to induce ketogenesis.  However a question many of you may be asking is “Do all fats have the same ketogenic potential?”  Well, the answer to that is no, some fats are better at inducing ketogenesis than others.  The most ketogenic fats we have are the medium-chain fats.

We consume many different kinds of fats, and all these fats vary in two different ways, chain length and saturation.  Saturation refers to the number of double bonds a fatty acid chain has, with no double bonds being a saturated fat, and one or more double bonds being an unsaturated fat.  The medium-chain fatty acids we will talk about here are all saturated fatty acids.  They are called medium-chain because they have between 6 and 12 carbons in their chain (1).  Here are a couple of diagrams of some of these medium-chain fats.


Caproic/Hexanoic Acid

Wednesday, September 26, 2012

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.

Wednesday, September 12, 2012

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.