The Intermittent Diet IF
In chemistry and physics, there is something called a triple point that describes a set of conditions under which a substance, like water, transitions between solid, liquid, and gas. A graphical representation of this triple point shows pressure on one axis, the temperature on another and a phase line. Altering the temperature or pressure can shift the relative position of the phase diagram to some degree and thus emphasize one phase over another. Thinking about the triple point is what inspired me to write this paper: I see Performance, Health, and Longevity as similar to the phases of the triple point and I suspect that IF may bring about an optimization of these parameters.
Consider this example: If you're one and the only purpose is to live as long as possible, there will be implications from the IF information that will make some compelling arguments. Optimizing lifespan (in the IF scheme this seems to be feast one day, fast one day) will likely by extension bring Health (an acute measure of longevity) near optimization, but Performance may suffer. Eating one day and fasting one day may not yield elite athleticism. One may be able to be quite good, but perhaps not elite and this is the similarity of altering the pressure/temperature conditions to shift the triple point to a different emphasis on solid, liquid or gas. I think it is obvious that some may desire to optimize performance and the pursuit of performance may necessitate levels of activity (wrestler Dan Gable does not get around so well on his very worn knees) and food consumption that is not conducive to longevity. Some degree of IF should still aid performance, but it may be different in duration and frequency than the person looking for maximum longevity.
Please just keep in mind that we try to present material that is germane to as broad an audience as possible and in such a way that people can make decisions about how best to implement a given technology to their betterment. It is not for me or anyone else to put forth dictates as to how (or why) to live or what the goals of the individual should be.
As Governor AHHHnuuuld might say: Enough Talk.
Program Optimization: Intermittent Fasting
For some time there appeared to be only one way to extend the average and total lifespan of organisms (anything from yeast to fruit flies to mice to monkeys): caloric restriction with adequate nutrition (CRAN). This involved feeding organisms about 60% of what they would normally eat. The results included: increased lifespan and ability to learn throughout life, significantly reduced body weight, reduced body temperature, modulated immune function, decreased blood glucose and insulin levels and an acute adrenal cortical response (short duration of elevated cortisol levels). It appears that the caloric restriction reduces non-enzymatic glycosylation of proteins (sugar sticking to proteins) and increases the organism’s ability to withstand stress via an increase in heat shock proteins and other cellular stress mechanisms. This is great stuff, but CRAN guaranteed that one was to be skinny—really skinny. Recently a protocol has emerged which appears to do everything desirable from CRAN, only better and seemingly without the downsides.
Intermittency represents life and natural processes far better than any type of steady-state model. This considered, it should not be surprising that a protocol of intermittent fasting (IF) bestows maximum Longevity, Health and perhaps, if properly tinkered, Performance. Recent research has shown that animals on an IF protocol in which they fast one day and eat all they want the following day to receive all of the benefits of CRAN with noted improvements.
Many of the metabolic alterations found in CRAN are encountered in IF, but there are some notable differences. In both protocols, there is a marked increase in beta-hydroxybutyrate (BHB), which is a ketone derivative of fat metabolism. The BHB appears to have a plethora of functions that are only now being explored4., but it appears ketosis is not the monster it has been portrayed as.5. Ketosis has been shown to prevent muscle wasting even in hypocaloric conditions and appears to be a preferred state for muscle accretion as well. In a specific study, IF conferred a greater neuroprotective effect than CRAN against a chemical irritant which mimics the oxidative stressors thought to induce Alzheimer’s and Parkinson’s. The IF protocol produced markedly higher levels of BHB that in other studies has proven to be a powerful agent in preventing lesions under toxic stressors.6.
It is important to note that these protocols induce markedly increased levels of ketone bodies despite the fact the experimental animals are fed a very low quality, high carbohydrate diet. According to most nutritionists, this is impossible, much like gaining muscle while on a hypocaloric diet. Those familiar with CrossFit, Evolutionary Fitness, and the Zone know the latter to be untrue if the conditions are correct. This is the case with CRAN and IF in which ketosis is achieved despite adequate liver glycogen levels. The why behind this has to do with the redundant systems devoted to fat accretion and sparing glucose for the brain. Sorry if that is vague, but that is a whole other paper. It is also interesting to note that one of the main indicators of a heightened level of conditioning is the utilization of fat as a preferred fuel source. The acts of CRANand IF dramatically increase the utilization of fat and so in effect increase one’s level of fitness independent of any other factors. This is what Arthur DeVany refers to as Metabolic Fitness.
The next action of IF I want to look at is particularly interesting in light of the action of growth factors and the well-fed vs. fasted states. In this study, several parameters were measured including blood levels of various biomarkers such as growth hormone (hGH) and insulin-like growth factor (IGF). IGF and HGH are crucial in actions such as tissue repair, hypertrophy, DNA repair, lipolysis, and, to some degree, strength. It is important to note that in recent years IGF has been linked to various forms of cancer due to its mitogenic (cell growth) effects.7. This appears to be due to excessive caloric and or carbohydrate consumption.
A brief digression into reproductive biology may be helpful here… especially for those of you who suffer from insomnia. All organisms express different characteristics under varying conditions. During times of relative plenty (lots of food), resources are directed to reproduction. This state is typified by high androgen levels and mitogens like insulin, IGF, epidermal growth factors, endothelial growth factors… it’s like spring for your body: everything is in bloom. During times of scarcity, resources are directed towards survival, and this state is typified by an adrenal cortical response (cortisol, epinephrine) and low androgen levels. This stress response increases cellular protection mechanisms such as heat shock proteins and apoptosis.
These 2 states have obvious survival implications and in normal circumstances, there is a seasonal balance and interplay between them. It is interesting to note that in general these two states are highly distinctive and show no metabolic overlap… except for one situation: Intermittent Fasting. In the IF state, we have elements of both the well-fed state and the acute stress state. As we will see below this is in stark contrast to CRAN.
It was found that the CRAN animals showed decreased levels of IGF. They also showed decreased rates of all cancers, as well as cardiovascular disease and neurodegeneration. The IF animals showed even greater reductions in disease states but with an increase in IGF. It appears that IF and CRAN act via different mechanisms. Professor Art DeVany made the point recently that there are a surprising number of redundant systems in place for fat accretion. This metabolically costly venture shows how important fat gain was to our ancestors and allows for quite a number of mechanisms to be underway with interventions such as CRAN and IF.
It is worth mentioning a few other important results found in the CRAN/IF protocols.
Both reduce blood glucose levels and insulin levels.6. An inevitable consequence of blood glucose is Advanced Glycation End products (AGE). This is a non-enzymatic addition of glucose to various body proteins. The faster this process is, the faster you are aging. This is why diabetics age faster than other people. For its part, insulin acts as a growth agent and is a factor in accelerated aging. Both protocols dramatically drop insulin and glucose levels, but IF is actually much more effective on both counts.
We are getting close to the practical application of all this information, but there are a few more theoretical items I want to consider. I mentioned previously that my goal is to find an optimized nutritional protocol for Performance, Health, and Longevity. A key feature of both optimum performance and “effective” aging is a reserve of muscle mass. The IF protocol, as mentioned previously, does not leave the organism in an emaciated state. Simple energy balance seems to account for most of this, as the IF animals consume on average the same amount as the ad-libitum controls and consequently do not lose weight. Add to this the finding that IF improves body composition and that IF with a low carbohydrate diet improves it even further. We also have an increase in IGF and neuroendocrine response to exercise.8. All of this bodes well for muscle mass and performance.
Implementation
Lots of theory thus far, but how does one do this? Whatever one’s approach, it is important to on average eat as much as one would have done with regular day-to-day feedings. This is an important distinction between CRAN, which usually peels off up to 40% of the individual’s body weight, and IF, which maintains bodyweight, muscle mass, and overall body composition. With that in mind, here are a few ideas.
Feast/Fast
Eat one day, don’t eat the next day… repeat. If one is following the Zone and eating say 16 blocks per day, this may mean a 32-block day. That is a lot of food! I suspect one’s protein needs are diminished due to the elevated hGH levels that induce improved nitrogen retention so you may be able to swap out some protein for increased fat intake. One may also need to increase fruit intake in place of some of the vegetables. This will mean both larger and more frequent meals on your “eat” days. Have fun with that, Zoners!
If you are “just eating,” then I guess just eat! Keep protein in most meals; make sure to add fat in the form of nuts, avocados and olive oil (remember, IF combined with high fat intake produces the best results). If you are feeling flat and not recovering from training, you may need to increase your fruit intake. For those seeking long life, this may be the way to go. There may be other approaches, but the data has shown this to be effective.
15 Hour-ish Plan
This is what I do most days and it seems pretty easy. Eat your last meal at 5 P.M. and fast until the following day. The duration is up to you, but if you can fit in some training while on an empty stomach, that is preferable. Once you break the fast it is time to get down and eat! Zoners, fit in all those blocks some way. Eaters… well, eat! Are you going to win the Arnold Classic doing this? Likely not, but if your results are similar to mine, you will be lean, feel very good and, depending upon your total caloric intake, possibly add some muscle mass. I am unsure if this abbreviated fast still produces high levels of BHB and IGF/HGH. If this is, in fact, the case, this may be the best way to optimize performance assuming one can take in adequate nutrition to support activity level. In essence, this plan may increase anabolic hormone status, improve fat utilization, improve insulin sensitivity, produce an acute adrenal cortical response, allow for adequate nutrition and perhaps even offer the life extension benefits of the feast/fast plan.
An additional tweak could be to combine the two approaches and this is essentially what Art DeVany suggested on the July 11 post at his site. Scott Hagnas of CrossFit Portland has a good account of a mixed approach here.
This is all the information you need to get started, but IF may not be the best way to go for you. I love it and I have been getting a lot of positive feedback. Tinker with it if you like, ask questions, and keep track of the results. Send me your experiences, good and bad, and we will follow up on this in a few months.
Books and References on the Topic:
1. Cordain L. The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Nutraceut Assoc 2002; 5:15-24.
2. Evolutionary health promotion. Prev Med 2002; 34:109-118.
Eaton SB, Strassman BI, Nesse RM, Neel JV, Ewald PW, Williams GC, Weder AB, Eaton SB 3rd, Lindeberg S, Konner MJ, Mysterud I, Cordain L.
3. The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism. 1983 Aug;32(8):769-76 Phinney SD, Bistrian BR, Evans WJ, Gervino E, Blackburn GL.
4. Prostaglandins Leukot Essent Fatty Acids. 2004 Mar; 70(3):309-19
5. Trans Am Clin Climatol Assoc. 2003; 114:149-61; discussion 162-3
6. Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proc Nat’l Acad Sci U S A. 2003 May 13;100(10):6216-20. Epub 2003 Apr 30
7. Glycemic index, glycemic load, and risk of gastric cancer. Ann Oncol. 2004 Apr; 15(4):581-4
8. Wan, R., S. Camandola, and M.P. Mattson. 2003. Intermittent food deprivation improves cardiovascular and neuroendocrine responses to stress in rats. Journal of Nutrition 133(June):1921-1929.
9. Exercise and insulin sensitivity: a review. Int J Sports Med. 2000 Jan;21(1):1-12
Literature:
Hagnas, Scott.2005.The Intermittent Fasting.In:``The Performance Menu``(July), Issue 6: S 4-8
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