Intermittent Fasting Protocols and Muscle Sparing

[madyogi]

Okay, so here is a particularly exciting study - Effect of intermittent fasting and refeeding on insulin action in healthy men. It has an admittedly small cohort of 8 men, so take it for what it is (perhaps not statistically applicable to larger populations), but it is the first study I've found that actually looked at a cohort of healthy, active people, as opposed to obese/diabetic/etc populations.

I haven't fully analyzed the methodology of this study, but at first glance it's quite interesting. The following is taken from the Discussion section of the study as linked to above.

"In the present study we have used a very simple intervention protocol with the aim of mimicking the perturbations in energy stores that are inherent in a physical active lifestyle with regular exercise sessions. In a wider perspective we have tried to unravel the significance of genes that may be responsible for an evolutionary selection process, i.e., the thrifty genes. In this context the used intervention seems inevitably small. Nevertheless, by subjecting healthy men to cycles of feast and famine we did change the metabolic status to the better, implying that the mismatch between our ancient genotype and the lifestyle of the westernized individual of today became smaller. To our knowledge this is the first study in humans in which an increased insulin action on whole body glucose uptake and adipose tissue lipolysis has been obtained by means of intermittent fasting. This result is in accordance with previously reported in rodents (2, 32). In these studies, fasting every second day increased the insulin sensitivity approximately sevenfold according to the homeostatic model assessment (2) and decreased the incidence of diabetes (32).

Prolonged fasting for 72 h with minimal physical activity has previously been shown to increase IMTG levels in humans (46). With the present fasting protocol and maintenance of habitual daily physical activity in the fasting periods, we had expected to detect a decrease in IMTG content in the skeletal muscle. The fact that this was not seen and that muscle glycogen content was unchanged could suggest that skeletal muscle is not immediately involved in recognition of acute energy oscillations. There is no doubt, however, that fasting for 20 h while maintaining normal daily physical activity must cause a temporary negative energy balance larger than normally experienced in a daily basis. This is also indicated by our finding of decreased plasma glucose concentrations after 20-h fasting. We did not have the possibility to estimate the hepatic glycogen stores, but from animal studies (17) we must infer that liver glycogen probably also decreased considerably during the 20-h fasting periods. It has previously been suggested that usage of muscle energy depots during fasting would be an evolutionary disadvantage, because it would lessen the capacity for physical performance and hence the ability to provide food (i.e., to hunt and gather) during periods of fasting (6, 45). The present findings support this view.


In contrast to the findings in skeletal muscle, the adipose tissue responded to the changes in energy balance as intermittent fasting changed the plasma concentrations of the adipocyte-specific hormones leptin and adiponectin. However, because we did not measure the energy stores in the adipose tissue during the intervention (e.g., by fat cell size), we cannot determine whether the change in adipokine release is merely a secondary response to intermittent fasting or whether the adipose tissue is an active recognizer of energy oscillations.

...

In conclusion, the findings that intermittent fasting increases insulin sensitivity on the whole body level as well as in adipose tissue support the view that cycles of feast and famine are important as an initiator of thrifty genes leading to improvements in metabolic function (6). We suggest that a fasting-induced increase in circulating adiponectin is at least partly responsible for this finding. The change in adiponectin, together with changes in plasma leptin with fasting, underlines the important role of the adipose tissue in recognizing the oscillation in energy stores. Finally, the data indicate that intermittent fasting and physical training may increase insulin action via different mechanisms because muscle energy stores did not change with the present fasting intervention."

It appears funding for this study came from a single grant from a Danish Diabetes Association, so it's hard to imagine that would skew the conclusions. Confirmation bias (preexisting ideology) is always a potential problem. And like I said, the sample size is admittedly small. Even so, it seems like a decent set of data, given what I'm trying to establish here.

 

[madyogi]

This is a great meta-analysis of the current state of research as of 2014 - Fasting: Molecular Mechanisms and Clinical Applications. It runs through dozens of studies on IF protocols from Bacterial studies all the way up to Human studies. There are no real conclusions, per se, only promising avenues for further investigation.

Some of the potential benefits include:

• Reduction in markers of inflammation and oxidative damage
• Increase in the production of Brain Derived Neurotropic Factor (BNDF)
• Improvements in insulin sensitivity (these are basically proven)
• Improved tolerance of certain cancer treatments

There are also implications related to cardiovascular disease and aging, but again they haven't been widely studied.

The first paragraph of the Conclusions and Recommendations section of the meta-analysis reads as follows:

Based on the existing evidence from animal and human studies described, we conclude that there is great potential for lifestyles that incorporate periodic fasting during adult life to promote optimal health and reduce the risk of many chronic diseases, particularly for those who are overweight and sedentary. Animal studies have documented robust and replicable effects of fasting on health indicators including greater insulin sensitivity, and reduced levels of blood pressure, body fat, IGF-I, insulin, glucose, atherogenic lipids and inflammation. Fasting regimens can ameliorate disease processes and improve functional outcome in animal models of disorders that include myocardial infarction, diabetes, stroke, AD and PD. One general mechanism of action of fasting is that it triggers adaptive cellular stress responses, which result in an enhanced ability to cope with more severe stress and counteract disease processes. In addition, by protecting cells from DNA damage, suppressing cell growth and enhancing apoptosis of damaged cells, fasting could retard and/or prevent the formation and growth of cancers.

In the end, the science is still very much not established on the potential benefits of IF protocols for adult humans, but the evidence shows a lot of promise.

 

[closed297]

particularly for those who are overweight and sedentary.

Animal studies have documented robust and replicable effects of fasting on health indicators including greater insulin sensitivity, and reduced levels of blood pressure, body fat, IGF-I, insulin, glucose, atherogenic lipids and inflammation.

Seems important to highlight this particularly for the sake of OP.

 

[Pegasus]

There is greaat info here for the other thread have you posted to that ?

 

[Pegasus]

This is semantics again. I get the fruit/veg blend, if it contains calories. But how is supplementing with BCAA's not technically a fast? My definition of fasting is basically not consuming calories, as in macro-nutrients. When I go to the doc for fasted blood work, they say I can have coffee or tea as long as it doesn't have sugar or cream in it. I assume your strict definition of a fast only allows for water, then?

Umm you do realise that not only does "fruit veg blend" contain calories but so bcaa's . Look it up if you do not believe me . So this becomes a very low calorie diet because bcaa's have calories . One could make the argument that the calories are so low it is effectively the same thing but hmm.

 

[madyogi]

There is greaat info here for the other thread have you posted to that ?

Yeah, I know. I haven't synthesized it for that specific purpose yet, but will try to soon.

 

[madyogi]

Umm you do realise that not only does "fruit veg blend" contain calories but so bcaa's . Look it up if you do not believe me . So this becomes a very low calorie diet because bcaa's have calories . One could make the argument that the calories are so low it is effectively the same thing but hmm.

Yes, I already posted something very similar (post #35), so we're tracking the same lines here.

 

[Pegasus]

More to the point you should be able to do ANYTHING you want especially when calculating optimal methods to achieve goals..

If that includes supplementing crucial nutrients during these fasting periods i don't see the point in arguing semantics..

If i were to make my own IF diet i would never purposely leave out crucial nutrients if it were necessary.
(Or any diet)

As i said this fad is youngish and is open to interpretation..
Simply arguing "but this is against the rules" (Of which there are none) Does not invalidate the core of an IF regime..

Like I said by all means do this and find the most effective method . Thing is though that a fast by definition contains no calories .

As both bcaa's and "fruit veg blend" contain calories this is no longer a fast .

I suggest you call it modified fast or very low calorie diet . As you say somewhat semantic.

I am liking the info on general benifits particularly on blood sugar .

 

[madyogi]

Like I said by all means do this and find the most effective method . Thing is though that a fast by definition contains no calories .

As both bcaa's and "fruit veg blend" contain calories this is no longer a fast .

To be fair, I think the bcaa's piece is still up for debate. My feeling is there is probably some metabolic function related to breaking down calories from, say 1 g of constructed protein from chicken breast, that isn't involved in 1 g of bcaa's, but that's just a feeling at this point.

The fruit/veg powder thing is probably the same as a smoothie.

Whatever, we're getting somewhere good here, so thanks for hanging in there, guys!

 

[closed297]

Like I said by all means do this and find the most effective method .

Now that's some great advice

 

[madyogi]

Okay, so two links for today, just to close the loop on the bcaa subject.

• Do BCAA (Branched Chain Amino Acids) Break Intermittent Fasting?
• Do BCAAs Spike Insulin? The Answer Here Is Not What You Have Read Elsewhere

The short of it all is that Peg is right. In the most technical sense, taking BCAAs is ingesting macro-nutrients, and doing so is breaking the fast, but only in a very minor, technical sense. The reality is that BCAAs do cause a slight insulin response, but one that is dramatically less than the increase caused by taking glucose and only slightly more than just drinking water.

So, it appears if we are interested in finding the best IF protocol possible, one that will preserve the potential benefits of spending more time in the fasted state while catabolizing structural protein as little as possible, supplementing with BCAAs on fast days could be part of that protocol.

Hopefully more soon on the Water Fast study and the concept of positive nitrogen balance.

 

[madyogi]

So, Peg put a graph in Post #10 of this thread, which was taken from a blog post based on a very interesting study. I tracked down the study, and I'm going to get really nerdy in order to break down what it means.


First off, we need to learn a bit of physiology. In the absence of incoming energy sources (ie, calories from food or drink), to keep running the body will use up whatever easily accessible stores of carbohydrate (various forms of sugar) it has available (usually in the form of glycogen from muscle and liver tissue). Then the body will enter what is known as a catabolic state, in which it begins to generate energy by breaking down its own tissues. This includes fat, muscle, and organ tissue. The study in question was specifically interested in why people (particularly obese people) die of starvation. The hypothesis is that the body essentially runs out of muscle tissue to catabolize, even while fat is still available. Somehow the energy gained from protein metabolism is more critical to survival under starvation circumstances than the energy gained from fat metabolism. That investigation is interesting enough in itself, but that's not what's most applicable to our current discussion.


Each of these metabolic pathways to energy (via fat and via muscle) generates its own byproducts. As protein is metabolized, nitrogen is its byproduct, and that nitrogen is excreted in the urine at a predictable rate. So this study used urine urea nitrogen levels to measure the degree of protein breakdown in the participants. Grams of nitrogen in urine can be converted to grams of protein broken down at a rate of 1g nitrogen to 5.57g protein. That is roughly how the graph posted by Peg was generated. So on Day 1 of that graph the urinalysis indicates 69g of structural protein was broken down for energy. What we don't see in that graph is that the urinalysis on Day 0 of this study indicates 34g of structural protein was broken down for energy. This is a super interesting fact that I'll return to in a minute, but first I'll say a bit more about the results of the study.


It ultimately concluded that during a 21-day water fast, participants lost an average of ~12 kg (~26 lbs), split evenly between fat-free mass (muscle) and fat mass. So, this should really put to rest any advocacy for long-term fasting as a means of healthy weight loss. Sure, you can lose a lot of weight quickly, but it's a very unintelligent and potentially dangerous way to do so. The study summarizes its findings by saying, "The data suggest that morbidly obese persons subjected to prolonged periods of starvation can die from protein depletion because there is constitutive amino acid oxidation for energy production, which can lead to depletion of vital proteins before the huge fat stores are consumed."


Now that we've established that, what might this study say about Intermittent Fasting?

Well, the fact that Day 0 (following a night's sleep after the last normal feeding day) showed enough urinary nitrogen to account for 34g of structural protein loss shows that humans shed a decent amount of structural protein as a matter of everyday living. Therefore, this notion that the subjects of this study shed the most structural protein (69g) after Day 1 might not be as scary as it sounds. These patients were morbidly obese, and the only exercise they got was taking shorts walks around the clinic in which they were confined. Hardly your average person trying to use intermittent fasting to lose a 20 pounds while staying active.


The truth is, human bodies are constantly recycling themselves, so a certain amount of tissue of all kinds is shed and regenerated every day. We tend to think in terms of calories in and calories out, or pounds on the scale from one day to the next, but bodies are more dynamic than equations. Equations are beautiful, and they approximate reality in a way that makes it easier to comprehend, but the map ain't the territory, folks.


That's all I have time/energy to say at the moment. Hopefully I'll get to a detailed discussion of positive nitrogen balance and tie that back to this study and the stuff about BCAAs in the near future.

 

[closed297]

Can you look into creatine as well please

I'd love to know if creatine would be considered "against the rules"

And if it is can you find another suitable source of quick energy to compensate for pre workout..

Asking as i specifically have added in the past from people who insisted on IF as a suitable pre workout (although i prefer egg whites when not in IF)

This was my non educated reference..

Nutrition Facts
Serving Size 1 tsp
Amount Per Serving
Calories 0 Calories from Fat 0
% Daily Value*
Total Fat 0g 0%
Saturated Fat 0g 0%
Trans Fat 0g
Cholesterol 0mg 0%
Sodium 0mg 0%
Potassium 0mg 0%
Total Carbohydrate 0g 0%
Dietary Fiber 0g 0%
Sugars 0g
Protein 0g 0%
Vitamin A 0% • Vitamin C 0% Calcium 0% • Iron 0%
* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

[h=3]Additional Serving Size Recommendations[/h]

Nutrition Facts
Serving Size 5 grams
Amount Per Serving
Calories 0 Calories from Fat 0
% Daily Value*
Total Fat 0g 0%
Saturated Fat 0g 0%
Trans Fat 0g
Cholesterol 0mg 0%
Sodium 0mg 0%
Potassium 0mg 0%
Total Carbohydrate 0g 0%
Dietary Fiber 0g 0%
Sugars 0g
Protein 0g 0%
Vitamin A 0% • Vitamin C 0% Calcium 0% • Iron 0%
* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

 

[Pegasus]

The semantics are taken care of by calling it a modified fast .

Yogi and I have been talking by pm about the amount of rise in blood sugar that would be caused and any possible downside .

 

[closed297]

Yogi and I have been talking by pm about the amount of rise in blood sugar that would be caused and any possible downside .

Do you mean glucose levels?

 

[Pegasus]

Yes the amount of glucose carries in the blood.

 

[Pegasus]

Yogi seems to feel the rise would be minimal.

 

[closed297]

Yogi seems to feel the rise would be minimal.

I don't doubt that..
As a general rule their both safe to give to a type 2 diabetic..(obviously looking to lower their glucose levels)

Also yogi after this research.. make a diet program including a IF protocol we can all follow to see if results vary (i'm the perfect candidate as i have type 2 diabetes)

 

[not2big]

I don’t eat between breakfast (9:00 am) and dinner (6:00 pm) is that considered intermitant fasting?

 

[Pegasus]

It is not quite long enough but dinner to breaky might be