The Effects of Intermittent Fasting on Human and Animal Health

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For injectables we would rather have long acting esters than short ones, as the long acting esters tend to pool up in your blood and generally leave you with more hormone at any given point. For orals we prefer those that either aromatize heavily, or cause an explosion of mass by similar estrogenic properties. The use of orals is mainly to kick off the mass cycle, gives you near instant results and puts your body in a good anabolic state when the long acting esters kick in.

With all that said the best steroids for mass are: Advanced users can also use things like Insulin and GH. Realize that with the exception of Test, Tren and Anavar, no steroid has a direct impact on fat burning. Even Test, Tren and Var have limited effects on fat burning. These steroids are going to help me loose fat.? Instead you should think of the steroids as muscle sparring. All steroids listed above meet the first requirement; they will all help you retain muscle in a calorie deficient diet.

However, if you are cutting you certainly do not want your steroids to be in the way either. Some steroids drol actually make it harder to loose fat. Others can bloat you up so bad that even with a low body fat percentage, most of your definition can be lost. So what we need here is steroids that are more androgenic than anabolic. We need steroids that have direct fat burning properties and steroids that do not aromatize heavily.

If we do use a long acting ester, we would prefer to use one that doesn? But I can take a guess and you guys that do participate in sports can probably figure it out given my explanations.

First lets looks at sports that require strength without increased mass. Any steroid that aromatizes heavily is not desirable here, as the extra water will certainly make you put on weight. Your best drugs for this purpose would be: Halo, Winny, Var and GH. If you can afford a few extra pounds like in the offseason or what not , Tren would also be a good steroid. Because EPO can have such a drastic effect on red blood cell count, it is NOT recommended that you use it along with steroids.

When you use any steroid, your HPTA will be suppressed. What this means is that your system is not producing any endogenous testosterone, which means you, won? What good is a cycle if you can?

So the key to cycling is to get your endogenous test back on track ASAP. One thing that will hinder HPTA activation is excess estrogen, whether it is from aromatizable steroids used in your cycle or whether it be endogenous estrogen. Using anti-estrogens like Clomid and Nolva will help prevent this negative feedback.

When your body sends out LH leutinizing hormone , it signals your testicles to begin producing test again. During your cycle, LH release will be suppressed and will remain suppressed for a few weeks after your cycle.

HCG mimics LH and helps your testicles start producing testosterone. For our purposes we should view HCG as a? However, HCG when used to heavily or for too long will actually suppress natural test production so it can be counter productive. Different cycles will suppress your HPTA to different degrees. Cycles including Deca and Fina will be more suppressive than cycles including Var and Primo. Before we outline the universal post-cycle therapy, we need to define when a cycle officially ends.

If you are using long acting esters, your cycle ends weeks after you take your last shot of the long ester I wont explain why, just accept it. If you are using ONLY short acting steroids OR your last shot of long acting steroids was over 3 weeks ago, and the only thing you? So given that, here is the universal post-cycle recovery program: HCG IUs 2 times a week. Clomid Day 1 Post Cycle: Clomid mg Days Alternate-day fasting, one model of intermittent fasting has been widely used in animal calorie restriction research because it has shown to result in reduced food intake over time and decrease body weight in rats In human trials, intermittent fasting has been shown to be equally effective as daily calorie restriction for causing weight loss in obese subjects While alternate-day fasting leads to calorie restriction over a two-day period in many rodent species, in some strains of mice, the animals managed to compensate for the calorie deficit created on fast days by increasing their intake on feast days twofold and thus keeping the total calorie intake over a two day period at the same level as in mice fed an ad libitum diet These mice managed to maintain constant body weight but, interestingly, still acquired some of the health benefits as rats on daily calorie restriction.

This lead to the hypothesis that by implementing periods of fasting, one could improve health without deliberately reducing calorie intake. My objective was to review relevant intervention studies on the effects of intermittent fasting on energy balance, cardiovascular risk factors, glucose metabolism, neurodegenerative pathology, tumor physiology and life span. The study will be important for the understanding of excess caloric intake and the management of obesity, and identify ways to alter cardiovascular, metabolic and neuronal health.

A systematic review of intervention studies in mammals, including humans was performed. PubMed between and was searched by use of relevant MeSH terms related to the effects of intermittent fasting on excess body weight, energy balance, aging physiology, cardiovascular risk factors, glucose metabolism, tumor physiology and neurodegenerative pathology.

All terms used are listed in Table 1. Furthermore, relevant review articles on calorie restriction and intermittent fasting were reviewed for additional relevant studies to include in the review. Studies were included in the review if short term fasting was the primary intervention and studied any of the above mentioned outcomes.

Studies that purposely restricted calories in the intermittent fasting group were excluded. A total of 36 studies were found. Consequently, alternate-day fasting is a widely used model for studying the effects of calorie restriction in rodent species This however is not a universal finding and numerous studies have reported no alterations in energy intake and body weight 17, In general, studies using Sprague-Dawley and Wistar rats show decreased energy intake and reduced body weights 15, The effect of intermittent fasting on body weight thus seems largely dependent on the animal genotype but could also be affected by the age of initiation, with optimal age varying in the various rodent strains Modified alternate-day fasting is one alternative model sometimes used in the intermittent fasting research.

Modified alternate-day fasting could allow for better maintenance of body weight than true alternate-day fasting protocols a complete every other day fast 30, Alterations in fat distribution were demonstrated in one study in which mice on both true and modified alternate-day fasting diets showed a redistribution of adipose tissue from visceral to subcutaneous depots without altering body weight overall Four rodent studies that examined the effect of alternate-day fasting on cardiovascular disease were included.

In general, rats maintained on an alternate-day fasting regimen lose bodyweight and display reduced blood pressure and heart rate, and improved insulin sensitivity, compared to rats fed ad libitum 28,29, Reduced blood pressure was also demonstrated in diabetic rats, proposing that alternate-day fasting can have a preventive effect on the progression of diabetes nephropathy This data is suggesting that intermittent fasting may reduce the risk of cardiovascular disease.

Furthermore, when myocardial infarction was induced in rats maintained on an alternate-day fasting diet, reduced infarction size, improved cardiac function, and increased survival was observed, compared to rats fed ad libitum 24,33, More interestingly, the effects on infarction size, survival rates and cardiac function can be observed even if the dietary intervention is induced after the ischemic event, by increasing the expression of angiogenic factors and increased vascularization of the damaged myocardium, proposing a novel non-pharmacological therapy for subjects with chronic heart failure A possible contributing factor for the cardio protective effects of intermittent fasting is increased levels of adiponectin, a hormone that exhibits both anti-athrogenic and insulin sensitizing effects and has been shown to protect cardiac myocytes against ischemic injury 44, Interestingly, alternate-day fasting demonstrates increased adiponectin levels in numerous rodent studies, even in the absence of calorie restriction and weight loss 39, A total of seven studies were found.

Increased insulin sensitivity, as indicated by decreased fasting concentrations of glucose and insulin, has been demonstrated in rodents on alternate-day fasts both with 19,28,33 and without 17 decreased calorie intake. In another study, as little as two 24 hour fasts per week, without calorie reduction overall, were sufficient to improve insulin sensitivity in mice In diabetic rats, alternate-day fasting reduces blood pressure, normalizes HDL levels, protects against glomerular damage and prevents development of diabetes nephropathy These findings suggest beneficial effects on glucose metabolism and improved markers associated with obesity and the metabolic syndrome.

A total of 17 studies were included. Numerous aspects of intermittent fasting and neuronal health have been examined in rodent species. Compared to rats fed ad libitum , alternate day fasted rats showed protection of age-related changes in dendritic spine number and morphology Other rodent experiments have showed increased neurogenesis in brains of rats maintained on an alternate-day fasting diet, as evident by increased number of newly generated neural cells in the hippocampus These results suggest that intermittent fasting could hinder morphological neuronal changes seen with normal aging and could thus slow down the neuronal aging process.

Other observed effects in mice include increased synaptic plasticity in the hippocampus and enhancement of learning abilities and other cognitive functions Intermittent fasting potentially exhibits desirable effects in manifest neuronal diseases. Rats maintained on alternate-day fasting diets show reduced brain damage and mortality rate in rodent models of stroke 19, After a period of 2—4 months on alternate-day fasting, a neuroprotective effect against induced hippocampal excitotoxic damage was observed Epileptic seizures in animals maintained on an alternate-day fasting diet lead to decreased brain damage 22,26, Interestingly, the protective effect of intermittent fasting against induced excitotoxic brain damage has been demonstrated in mice despite no reduction in calorie intake or weight loss.

Furthermore, mice on alternate-day fasting diets showed greater resistance to excitotoxic injury than mice on daily, controlled calorie restriction When mice with progressive demyelinating disorders of the peripheral nervous system were put on an alternate-day fasting diet regime, hampered disease progression was observed as indicated by improved nerve morphology and performance compared to mice fed ad libitum Furthermore, alternate-day fasting leads to increased functional recovery after experimentally induced spinal cord injuries in rats, independently if the alternate-day fasting regimen is implemented prior or after the spinal cord is injured 27, If this effect is demonstrated in humans, intermittent fasting could potentially serve as a non-pharmacological therapeutic alternative in the rehabilitation process in subjects with spinal cord injuries.

The effect in mice was greater with alternate-day fasting compared to daily calorie restriction, suggesting that increased time span in the fasted state has additive effects other than those attributed to calorie restriction alone The beneficial effect does however not appear universal to all neurologic disorders. No desirable effect was observed in an animal model of amyotrophic lateral sclerosis ALS , indicating that intermittent fasting has no beneficial effect on the development of this motor neuron disease To study the potential anti-carcinogenic effect of intermittent fasting, three different aspects of tumorgenesis have been studied: Seven studies were included.

Subjects with elevated IGF-1 levels have been reported to exhibit increased risk of several cancer types. Furthermore, high circulating levels of insulin and IGF-1 in combination are often seen in subjects with obesity, insulin resistance and type 2 diabetes, patient categories that are also more likely to be affected by cancers Rats on alternate-day fasting diets showed decreased levels of IGF-1 and proliferation rates of T-cells and prostate cells Cell proliferation rates are considered a central element in the development of cancers Decreased cell proliferation has previously been demonstrated with reduced feeding frequency alone, despite matched calorie intake In a third study, true but not modified alternate-day fasting decreased IGF-1 levels in mice.

Cell proliferation rates were however reduced in both groups, even in the absence of weight loss There is however some conflicting data in regard to intermittent fasting and IGF One might suspect that two 24 hour fasts per week would be insufficient to exhibit the anti-carcinogenic effects.

However, Anson et al. The authors suggested a difference in the way intermittent fasting and calorie restriction influence the growth hormone -IGF-1 axis and insulin signaling pathways.

The relevance of IGF-1 for tumor growth in intermittently fasted animals, with or without calorie restriction remains thus a subject for further clarification. Recent research has also examined intermittent fasting and its direct effect on tumor development. OF1 is a strain of mice that spontaneously develops age related lymphomas at a high rate.

There was no difference in food intake or body weight between the two groups, suggesting that intermittent fasting has a protective effect on lymphoma development in this mouse strain, and that the effect was independent of the total calorie intake. The effect of intermittent fasting on induced hepatocarcinogenesis has also been examined.

When rats were put on a 48 hour fasting regimen once per week, they developed less preneoplastic lesions compared to rats fed ad libitum over a 48 week period The effects of shorter, more frequent fasts, such as alternate-day fasting on hepatocarcinogenesis remains a subject for future research.

Consequently, studies to date indicate that intermittent fasting hampers cell proliferation rates in a variety of cell types, and that it could potentially protect against direct development of some cancer types. Two studies looked at survival per se. They propose that animals on alternate-day fasting diets increase life span compared to those fed ad libitum 15, The magnitude of life span enhancement seems to be dependent on animal strain and age of initiation Furthermore, in one study, only rats on alternate-day fasting diets survived to 30 months of age compared to a mean lifespan of months for rats fed ad libitum It is merely speculative if the effect on longevity is secondary to the above described effects such as decreased body weight, improved insulin sensitivity, improved cardiovascular health, decreased tumor growth and improved neuronal health, or if intermittent fasting might have some distinctive effect on the aging process.

No study to date has specifically studied the effect of intermittent fasting without calorie restriction on lifespan, although the effects that have been described are expected to increase life span. Some other interesting effects than the primary addressed in this review were observed in various studies. Many strains of laboratory rats develop spontaneous progressive kidney failure with development of proteinuria and glomerulosclerosis. Rats fed on alternate days showed preserved kidney function as demonstrated by preserved glomerular filtration rate and renal plasma flow, compared to rats fed ad libitum Analgesia, which may be attributed to negative modulation of synaptic transmission in nociceptive neurons in the dorsal horn of the spinal cord, has also been reported in rats maintained on an alternate-day fasting diet This finding opens up the question whether intermittent fasting alone or in combination with a pharmacological agent could serve as a useful new therapeutic approach for treating pain.

Fasting is one of the five pillars of Islam. During the holy month of Ramadan, Muslims restrain from fluid and food intake during daytime for the whole month.

Worldwide, there are more than one billion Muslims, of whom the majority fast annually The holy month of Ramadan could thus potentially be a good period to study prolonged short term intermittent fasting in humans on a large scale. A total of 17 studies were found. Conclusions are however very hard to draw from these studies.

Apart from the obvious difficulties with doing randomized controlled trials there is a number of confounding factors 59, Such confounding variables include:. Furthermore, the studies were generally of poor study design with few participants and lack of control group. As a result the studies are highly inconclusive with the effects on body weight and blood lipids with some studies showing unchanged body weight 59,61 while others show weight loss Therefore, no objective conclusions could be made about this type of short term intermittent fasting and cardiovascular and metabolic risk factors, and further research of higher quality is warranted.

The fasting participants were compared to the non-fasting participants and all food was delivered from the same kitchen, thus eliminating some of the confounding factors above 60, Apart from a small difference in body weight 0,7 kg that could be explained by hydration status between the two groups, no differences were observed in blood glucose levels, hematocrit, cortisol levels, inflammation markers or physical performance.

In another study, fasting healthy men and women were compared to a matched non-fasting group with regard to inflammation markers and blood lipid status No differences were observed in body weight, total cholesterol, triglycerides or LDL levels.

There was however an increase in HDL levels and decreased inflammation — proposing a beneficial effect in the fasted subjects.

Thus, there are some data suggesting altered health markers during the month of Ramadan, but more research is needed if any objective conclusions about this type of intermittent fasting and the factors studied in this review ought to be drawn.

To date, very few human intervention studies have tried to replicate the reported effects of alternate-day fasting seen in rodent studies. Only six such studies were found, with somewhat disappointing study designs The sample size in these studies was rather small, ranging from eight to sixteen participants, and the study period was often very short.

Only one trial included a control group. The results are summarized in Table 2. In both true alternate-day fasting trials, a decreased body weight was observed 66, In modified alternate-day fasting trials, maintained bodyweight was observed in lean 65,69 but not obese 64,68 subjects. In obese subjects, a modified week alternate-day fasting regimen resulted in weight loss, reduced blood pressure and heart rate, and improved markers for cardiovascular health, such as decreased total cholesterol, decreased LDL and triglycerides, increased HDL concentrations and decreased oxidative stress and systemic inflammation, suggesting that alternate-day fasting might be a novel strategy for decreasing body weight and improving cardiovascular health in the obese population 64, To examine the effects of alternate-day fasting on glucose metabolism, eight healthy men were maintained on a 20h modified alternate-day fast for two weeks.

Despite unaltered body weight and habitual physical activity, insulin dependent glucose uptake increased, and increased adiponectin levels were observed In another trial, the insulin sensitizing effect of true alternate-day fasting was observed through reduced insulin response to a standardized meal in men, but not women — suggesting a potential sex difference in the effect of alternate-day fasting on glucose metabolism Although not demonstrated in all human studies 68,69 , these results indicate that alternate-day fasting might mimic the insulin sensitizing effects observed in rodents on alternate-day fasting diet, and that the effect might be due to increased adiponectin levels.

Sex differences were also observed in another study where healthy men and women were fasted on alternate days. In this study, HDL levels were increased in women only, and triglycerides were decreased in men but not women Increased insulin sensitivity was suggested by decreased insulin levels with unaltered glucose levels. In this study, blood pressure was unaltered, but the study duration was merely 22 days. In contrast, one trial showed decreased blood pressure and resting heart rates in subjects on modified alternate-day fasting regimens for 10 weeks, suggesting that longer intervention periods might be needed for this effect to occur There is, however, conflicting data from another study that utilized a two week crossover study design and randomized eight healthy men to a modified alternate-day fasting diet or a standard diet.

No differences were observed in body weight, blood lipids, glucose metabolism or hormone levels, and there was a decrease in energy expenditure after the 2 week period in the alternate-day fasting group More controlled studies, with larger sample sizes and longer study durations are thus needed to bring clarification in this matter.

No human trial has directly examined intermittent fasting and tumor physiology. A single two day fast increases endogenous GH-production fivefold, reflecting the metabolic adaptation to fasting, including increased hepatic glucose production, lipolysis and nitrogen conservation However no significant changes in IGF-1 are seen after a single fast period in human subjects, suggesting that repeated fasts and longer intervention periods might be necessary to mimic the changes in IGF-1 and altered cancer growth observed in some rat studies.

Whether a prolonged alternate-day fasting regimen can alter IGF-1 levels in humans remains an area for future research. Furthermore, no human trials to date have examined the effects of intermittent fasting on neuronal health or life span. The exact mechanism by which calorie restriction and intermittent fasting exhibits its effects on various organ systems remains unknown. Alternating periods of anabolism and catabolism during intermittent fasting might further increase the cellular stress resistance.

Other displayed effects are increased production of neutrophilic factors and antioxidant enzymes, ketone body formation and altered metabolism enzyme production 5. A variety of questions often arises when discussing intermittent fasting and human health.

It is often believed that blood sugar levels will fall to pathological levels if prolonged fasts are implemented. A characteristic decline in mood and energy levels before lunch among humans is often attributed to a drop in blood sugar.

However when actually testing blood sugar levels in healthy subjects prone to this phenomena, no actual decline in blood sugar to pathologic levels was seen during a 24 hour fast Furthermore, a double-blind, placebo-controlled study of two days of calorie deprivation showed no adverse effect on cognitive performance, activity, sleep, and mood, when the subjects were unaware of the calorie content of the treatments The homeostasis of body weight regulation and hunger signaling is composed of complex circuits of both central signals including orexin, neuropeptide Y, melanin concentrating hormone and alpha-melanocyte, and peripheral signals from the gut and adipose tissue, such as ghrelin, peptide YY and leptin The interplay between these and other endocrine signaling systems and its effect on body weight regulation and subjective feelings of hunger and satiety remains largely unknown.

The hunger response however seems to be highly adaptive in different meal patterns. Ghrelin, a gut derived hormone, is considered a meal-initiation signal. It increases during fasting and usually peaks in concentration before an anticipated meal, paired with increased feelings of hunger, and decreases after feeding. Increases in subjective feelings of hunger might be the single most important factor to consider when discussing the applicability of intermittent fasting as a therapeutic or preventive intervention in human subjects.

In obese patients, a 14 day total fast lead to strikingly decreased body weights and decreased blood pressure, without causing increased hunger sensations.

Thus a hunger suppressing effect of prolonged fasting was demonstrated This anorexic effect might be attributed to the evolutionary purpose of seeking for nutrients in absence of food. The experiment, dating back to , was effective and well tolerated. Only one study has directly examined the feelings of hunger and fullness in non-obese subjects on an intermittent fasting diet, by using a mm visual analog scale The subjects were fasted on alternate days and reported an increased feeling of hunger from 37 to 56 mm and decrease in feeling of fullness from 43 to 23 mm when the dietary intervention was initiated.

The magnitude of hunger did however not change during the intervention period as repeated measurements were taken, and feelings of fullness actually increased some over time.

The duration of this study was only 22 days and it is still purely speculative whether and adaptation to the new meal pattern would occur in a longer time span. In contrast, modified alternate-day fasting in obese asthmatic patients did not significantly increase the subjective perception of hunger from baseline during the eight week long intervention period Whether repeated bouts of short term fasting can alter hunger hormone signaling or demonstrate the same anorexic effect as the long term fast described above is highly speculative and an interesting area for future research.

It is commonly believed that multiple small meals increase metabolism and lead to increased overall energy expenditure. Following every meal there is an increase in expenditure due to the processing of the nutrients, commonly referred to Thermic Effect of Food TEF A common belief therefore is that increased meal frequency leads to increased TEF and increased overall energy expenditure with multiple meals, and that intermittent fasting accordingly would decrease metabolic rate and lead to increased fat accumulation and possibly obesity.

According to current research though, TEF is proportional to the calorie content and vary with macronutrient composition with the highest increase in energy expenditure observed with a high protein diet and not meal frequency per se , as demonstrated by the equal TEF in different meal patterns under iso-caloric conditions 79, Furthermore, one study examined alterations in resting metabolic rate in human subjects on alternate-day fasting diets, and found no changes after a 22 day period According to these findings, any potential decreases in metabolic rate would be due to decreased total calorie intake and not fasting per se.

Increased levels of both ACTH and corticosteroids can be noted in rodents maintained on alternate-day fasting diets compared with rats fed ad libitum 28,29, Apart from the obvious notion that cortisol is one of the major hormones responsible for glucose utilization during fasting, the question arises whether the increased stress in any way could be harmful to the human organism.

The molecular stress response in intermittently fasted subjects seems markedly different from the one associated with uncontrolled stress. In contrast, in uncontrolled stress, down regulation of the mineral corticoid receptor has been noted. Furthermore, deleterious stress responses are associated with a decrease in the expression of brain-derived neurotrophic factor BDNF , a response quite the opposite of calorie restriction and intermittent fasting, where increased concentrations of BDNF have been observed in numerous studies 4.

In conclusion, the controlled stress response from intermittent fasting seems fundamentally different from the one by uncontrolled physiological and psychological stress. Conversely, In line with the mechanisms described above, the increased stress might be one of the necessary factors for initiating molecular resistance for larger stressors, and thus promote some of the beneficial effects of intermittent fasting.

One potential serious side effect of intermittent fasting would be loss of muscle mass. Theoretically, food deprivation would result in depleted hepatic glycogen stores, leading to increased proteolysis and flux of amino acids from skeletal muscle for hepatic de novo gluconeogenesi s, to maintain healthy blood glucose concentrations.

As discussed previously though, a 24 hour short term fast is insufficient in duration to deplete liver glycogen stores in healthy subjects Up to 40 hours of total fasting does not stimulate catabolic processes and lead to skeletal muscle atrophy Modified alternate-day fasting and loss of lean body mass was investigated in only one study in the systematic search.

No loss of fat free mass in the absence of weight loss was observed compared to a control group fed a standardized diet Furthermore, an increase in ketone body concentrations has been observed in subjects on alternate-day fasting diets in both human and animal studies 17, Ketone bodies spare skeletal muscle from breakdown by providing non-glucose energy substrate for various tissues, of which the brain is the most important, and thus decrease the need for protein-derived substrates for gluconeogenetic conversion to maintain glucose homeostasis Available data thus suggests that short term fasting does not deplete hepatic glycogen stores to the extent that markedly increased proteolysis and gluconeogenesis becomes necessary to maintain healthy glucose concentrations.

Still this notion needs to be clarified in future research of longer duration. Intermittent fasting in the form of alternate day fasting in many instances reduces overall energy intake, with no obvious adverse effects, and thus becomes a model of calorie restriction in both human and animal subjects. Secondary to reduced energy intake and weight loss, effects such as reduced risk factors for cardiovascular disease, and improved glucose metabolism have been demonstrated in both animal and human subjects on true and modified alternate-day fasting diets.

In rats, protection against ischemic injury and improved survival has been demonstrated in both myocardial and cerebral ischemic events. Other beneficial effects, such as slowing the neuronal aging process and increasing cognitive functions and memory, have been observed.

Additionally, calorie restriction can reduce cancer risk and increase life span in rodent models on alternate-day fasting diets. Some effects occur even if the subject maintains body weight, suggesting that the reduced meal frequency or prolonged time in the fasted state might have some additional effects regardless of overall calorie restriction and weight loss. In humans, modified alternate-day fasting diets might be easier to adhere to and they seemingly lead to less pronounced weight loss than true alternate-day fasting.

Without causing weight loss, effects such as improved fasting insulin have been demonstrated in both animals and humans. In line with these findings, adiponectin increases in rats and humans on both true and modified alternate-day fasting diets in the absence of calorie restriction. Additionally, in mice, fat redistribution from visceral to subcutaneous stores has been observed despite unaltered overall body weight. If this effect proves to be true in human subjects it could propose reduced disease risk despite unaltered body weight.

Animal data further indicate some beneficial effects of intermittent fasting diets even without calorie restriction. Neuronal health improvements such as resistance to excitotoxic injury have been observed. Alternate-day fasting in animals also leads to improved recovery after induced spinal cord injuries and progressive demyelinating disease of the peripheral nervous system, in the absence of calorie restriction. Furthermore, in animal studies, changes associated with retareded tumorgenesis, such as decreased cell proliferation rates in various cell lines and decreased incidence of lymphoma, have been observed.

Whether these observations are valid in human subjects as well remains an interesting area for future research. Future research is warranted to test whether the health promoting effects described in animal studies have some validity in humans. We are in the very infancy of research on intermittent fasting in human subjects and future studies with larger sample sizes, longer durations and of better study design must be completed before any definite conclusions can be made regarding intermittent fasting and human health and the applicability to modern lifestyle.

My sincere gratitude to Staffan Lindeberg and Bengt Zöller for helping me set up the systematic search, for all the intellectually stimulating discussions and for the guidance in writing this review.

The complete search term used was: Alternate day fasting and body weight, glucose metabolism and cardiovascular health in humans. Very interesting stuff, I love that even though some of the references were a bit over my head the latin names for some illnessess and the implications of these, etc most of it was completely comprehensible eventhough it was made for medical purposes.

Great summary of some of the work that has been done to date. Some more recent studies showing timing i. Keep up the nice work. Appreciate you and Berkhan sharing your work with us! Thanks for taking the time to write this up, Bojan. It was a very nice, in-depth look at the studies surrounding IF and written in a way that can appeal to the medical-savvy people, and the general public interested in health like myself.

There used to be a time when people were trained to write and communicate, and from the above article this time has clearly passed. I can see that you are using this article to try to bring people in and eventually sell them something. The way you are approaching it wont work-unless you really think people are going to read 10, words of science crap instead of just closing your site and going elsewhere.

While it may seem like jargon to you, it is the preferred lexicon for scholarly publications. Do NOT presume their level of education. I once listened to an Immunology professor at a University complain that the only articles he could understand in Science the journal were the ones on Immunology.

Trust me; if you were to pick up and try to read a scholarly academic article outside of your field, you would react the way Jeff is reacting. Oh dear Jeff, you have clearly shown that this level of academia is lost on you. This is an excellent review of the available literature, written by a highly educated person.

This is an extremely disrespectful comment that shows your lack of intelligence. Think things through before you comment in future. It is Your comment that is extremely disrespectful comment and shows a lack of intelligence and knowledge of how many different styles there are in the world. I have an MS in Microbiology and have been employed as a programmer and technical writer for over 25 years. Both Jeff and Notjeff seriously?

Notjeff is sadly also correct. However, Audience is Everything. If you want this information to be read and understood by people who are not your thesis committee or people with an MD or PhD in your field, you need to re-write it.

This study confirms much of the anecdotal evidence that I had already heard about the possible long-term effects of intermittent fasting. Interesting timing of this post as I was just talking with a co-worker about the benefits of intermittent fasting and the general practice of fasting.

Although it has been a while many years since I have practiced fasting, it is a ritual that I have studied and used its healthy benefits in the past. I have used short fasts of less than 36 hours and longer fasts of 7 days for personal research,purposes and practice. After having lived several years in an unhealthy way, I have re-tooled my lifestyle into a sustainable healthy way of living and have lost 55 pounds in the past year.

The subject of intermittent fasting came up as I believe that I will begin a regular practice of IF as a part of this lifestyle. I am looking forward the time when I can read your complete work as I have only scanned it this morning. Thanks for sharing your work with me. Thank you for sharing your research. The popular models of IF being 5: Do you have any results on their benefits from your research? I need to leave a quick comment just as I started reading The best and biggest recource base for the IF is by far Martin Berkhan, and his website leangains.

Now back to the reading…. It is a great summary and I do appreciate your work on this. Thanks for sharing this. It seems like most of the research in this area has been done on type two Diabetics. Ori may in fact be the first well-known proponent of IF and Warrior Diet should be recognized as one of original mainstream publications advocating IF for general health and physique improvements….

I spend much of my time researching information on fasting from peer reviewed journals through my university. I find the health benefits of IF, especially autophagy, are profound but tend to be poorly understood. I have the article you posted. What do you know about this topic? Lots of writing but I was conflicted.. You talked in the beginning about this being your baby.. You made it sound like you had stumbled on some gold nuggets of previously unknown information.

Nice resource of information overall but I still fail to understand why so many people regard IF as some unique idea or think of it as a new way to solve an old problem. I tried it for a full year before realizing that my results were identical to when I ate 6 meals a day for a decade. Is it staving off disease in me a little longer and giving me a future benefit in that respect? Possibly but not conclusively. It matters little and this just seems to justify that. Eat 6 meals if you like or eat 1 or 2.

I can see great benefit in people linking to the article as a place to find many important studies on fasting. Most appreciate the hard work, and you choosing to publish this free for all to read and benefit after the hours of work. Will put several links up to it. It is true that junk food can totally screw up any health benefits of IF and the people that bash it did just that, or did unhealthy low carb or too low calorie or had lots of stress in other areas of life.

IF can also backfire if done to extreme. I mean come on. Thank you for all the work of putting it together! From perspective of 1. Mood and energy 2. Long-term health and longevity 3. Physical and mental performance. All other things being equal, according to current data, should someone training two or three times a week fast once a week for the whole day or daily for about hours?

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