“That which does not kill me makes me stronger”
 – Friedrich Nietzsche

Diet & Fasting

This section offers a review of the health benefits associated with fasting, not limited to simply weight loss. The different types of fasting are reviewed along with an introduction to the multitude of proposed health-based arguments for incorporating fasting into one’s lifestyle. Finally, for those interested, background information is presented  to provide an understanding of the proposed mechanisms behind the apparent health benefits related to fasting.


See also:


Diagnosis-Directed Diets:


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Definitions and Terminology



Fasting consists of ingesting minimal to no amounts of food or caloric beverages for periods ranging from 12 hours to three weeks or more. Many religions incorporate fasting rituals including Muslims during the month of Ramadan, Christians, Jews, Buddhists and Hindus who traditionally fast on designated days of the week or calendar year. The spiritual benefits of fasting are left for discussion elsewhere but the health implications are addressed here.


Various forms of fasting are now promoted for a range of benefits improving general health and disease prevention to weight loss.  For the purpose of discussion here, the following definitions are applied:


Fasting: Ingesting water only or very low calorie (less than 200 kcal/day), for 24 hours or longer.

Caloric restriction (CR) or Energy Restriction (ER): Daily caloric intake is reduced chronically, typically by 20–40% and meal frequency is may or may not be maintained. 

Continuous Energy Restriction (CER): Caloric or energy restriction is continued on a daily basis

Intermittent Energy Restriction (IER): Defined as periods of energy restriction interspersed with normal energy intake, generally consisting of alternating periods of reduced caloric intake. The most studied IER approaches are either two consecutive days of ER per week (“two day”) or alternate days of ER (ADER), typically with a restriction which is 60%–70% below estimated requirements, or a total fast on alternate days.

Starvation: Chronic nutritional insufficiency result in impaired health and eventually death.


Intermittent Energy Restriction (IER) vs Continuous Energy Restricion (CER)

One advantage of IER over CER is that IER only requires the individual to focus on ER for specifically defined days during the week which is potentially more achievable than the standard approach of CER which is generally associated with poor compliance. The second advsntage is that many beneficial metabolic effects achieved with weight loss and energy restriction are related to the energy restriction per se, not the weight loss. There may appears be greater levels of compliance for the IER vs CER regimens bsut this is not supported in all studies. Furthermore, once an individual has attained their target weight, it appears that repeated episodes of marked ER for short periods during the week provide continued metabolic benefits without weight loss.


Interestingly, while it was theorized that people on IER regimens would overeat on days not targeted for calorie restricion, studies revealed the opposite: rather than eating more on unrestricted days, people tend to have a “carry-over” effect of reduced caloric intake by as much as 20%.


Benefits of Fasting and Intermittent Energy Reduction (IER) – An Overview

Based on the existing evidence from both animal and human studies,  there is a great potential for  incorporating periodic fasting or IER during adult life to promote optimal health and reduce the risk of many chronic diseases, particularly for those who are overweight and sedentary. While research has evaluated multiple regimens of fasting & IER, no specific regimen is notably “the best” so there appears to be significant room for individual approaches to meet individual needs.


Fasting and the metabolic syndrome

Metabolic syndrome (MS), defined as abdominal adiposity, combined with insulin resistance, elevated triglycerides and/or hypertension, greatly increases the risk of cardiovascular disease, diabetes, stroke and Alzheimer’s Disease. ER can prevent and reverse all aspects of the MS in rodents, and human studies support similar benefits: abdominal fat, inflammation and blood pressure are reduced, insulin sensitivity is increased, and the functional capacities of the nervous, neuromuscular and cardiovascular systems are improved.


Multiple hormonal changes typify metabolic syndrome including elevated levels of insulin and leptin and reduced levels of adiponectin and ghrelin. Elevated leptin levels are typically reflective of a pro-inflammatory state, whereas adinopectin and ghrelin can suppress inflammation and increase insulin sensitivity. Ghrelin is a peptide hormone produced by ghrelin cells in the gastrointestinal tract and functions as a neuropeptide in the central nervous system. Ghrelin plays a critical role in regulating the distribution and rate of use of energy. These hormone changes are all reduced with ER.


Research on fasting and IER have documented benefits that include greater insulin sensitivity, and reduced levels of blood pressure, body fat, insulin, glucose, harmful cholesterol and inflammation. Fasting and IER regimens can suppress disease processes and improve functional outcome in many disorders that include myocardial infarction, diabetes, and stroke.


Overweight subjects maintained for 6 months on a twice weekly IF diet in which they consumed only 500–600 calories on the fasting days, lost abdominal fat, displayed improved insulin sensitivity and reduced blood pressure. In another study, of 743 patients who participated in a 7-day juice fast (intake <350 kcal/day) and  with a 3 day stepwise reintroduction of food, 78% of the fasting patients reported improvement of their health through fasting.


However, fasting is not recommended for everyone and fasting regimens are not recommended for children, the very old, and underweight individuals, as it may be possible that fasting & IER would be harmful to these populations. Fasting periods lasting longer than 24 hours, especially those lasting 3 or more days should be done under the supervision of a physician. For suggested recommendations for incorporating IER into one’s lifestyle, see below: Recommendations for Incorporating ER for Brain Health.


Areas of potential benefit related to Energy Restriction (ER):

  1. Weight loss
  2. Improving cardiovascular health
  3. Improving insulin sensititivy, reducing risk for diabetes
  4. Improving cognitive functioning
  5. Improving sleep
  6. Improving fatty liver disease
  7. Reducing oxidative stress and the risk of cancer
  8. Reducing depression
  9. Reducing symptoms of fibromyalgia
  10. Reducing chronic pain and inflammation
  11. Reducing risk of nerve damage and injury
  12. Potentially improving lifespan


For a more in-depth review of these many potential benefits of fasting, see below.


(1) Energy Restriction (ER) – Weight Loss

The immediate and obvious benefit of fasting is weight loss, the most frequent motivation behind fasting. The rate at which one loses weight is specifically dependent on the extent to which a person’s caloric intake is reduced compared with one’s daily caloric needs. This simple fact may drive one interested in losing weight to consider fasting as a tool for weight loss. However, a variety of fasting options can be considered based on the person’s individual needs and preferences.


Weight Loss: IER vs CER

Overall, multiple trials to date have found IER to be equivalent to CER for weight loss but possibly superior to CER for reducing body fat and, more importantly reducing visceral fat. Visceral fat, the intra-abdominal fat surrounding abdominal organs, produces more active agents that contribute to oxicative stress than subcutaneous fat. Thus, a weight loss regimen that includes fasting or IER may provide better health benefits than CER.


Preserving Muscle During Weight Loss: IER vs CER

Weight loss diets should reduce body fat stores and, as far as possible, preserve muscle to maintain physical function. CER is known to reduce muscle mass in addition to body fat with typically 10%–60% of weight reduction using CER is muscle mass, depending on initial body fat, the degree of energy restriction, extent of exercise and protein intake. IER and IF diets may preserve muscle mass more than CER. However the concern is that spells of severe restriction with IER and IF could lead to greater losses of muscle mass than the modest daily energy restriction with CER. There is, however, little reseach to answer this question,


Some weight loss trials amongst people who are overweight or obese suggest losses of muscle mass with IER and CER are equivalent, (between 20-30% of weight loss). There was however a greater preservation of muscle mass (20% of weight loss) with a high protein IER (1.2 g protein/kg weight) compared to the standard protein CER (30% with 1.0 g protein/kg body weight. Studies of ADER reported the proportion of weight lost as muscle mass as low as 10% in women with obesity and as high as 30% amongst non-obese subjects. Subsequent studies show that exercise helps to retain FFM amongst subjects undergoing IER.


(2) Energy Restriction (ER) – Improving Cardiovascular Health

Alternate day fasting (ADF) with a low-fat diet has been shown to be effective for weight loss and to be protective of the heart against coronary artery disease. However, given that the majority of Americans consume a high-fat diet, a study was performed to determine if alternate day fasting (ADF) with a high-fat diet would also be effective. In this study, both ADF with high and low fat diets were shown to result in weight loss, a reduction in waist circumference, and lower levels of LDL cholesterol (the “bad” cholesterol) and triglycerides whereas loss of muscle mass, levels of HDL cholesterol (the “good” cholesterol) and blood pressure remained unchanged. There were no significant differences in the findings between the two groups, indicating that it is the ADF that contributed to the protective effects.


(3) Energy Restriction (ER) – Improving Insulin Sensititivy, Reducing Risk for Diabetes

Multiple studies have demonstrated the benefits of fasting including improvement of insulin sensitivity, a clear factor in reducing the risk of developing diabetes.


Improving insulin sensititivy: IER vs CR

Improvements in insulin sensitivity appear to be greater in IER and IER appears to bring about a modest increase in adiponectin which has a pivotal role in insulin sensitivity and the development and progression of cancer, heart disease and diabetes. Unfortunately, most of the research is with animal studies or shor term human studies so the long term benefits have not been definitively confirmed.


 (4) Energy Restriction (ER) – Improving Cognitive Functioning

Evidence suggests that energy restriction (ER) – and exercise – can enhance brain function, and may reduce age- related cognitive decline in humans. It does so via actions on synapses (the spaces between adjacent nerve cells where communication via neurotransmitters occurs) and neural stem cells by increasing ‘synaptic plasticity’. The term ‘synaptic plasticity’ refers to changes that occur in the numbers, structure and functional status of synapses as adaptive responses to a range of environmental challenges  including those that are voluntary (e.g., problem solving, writing, and competing in sport) and those that are unwelcomed (e.g., a traumatic injury or disease). Synaptic plasticity is essential for learning and memory, and to preserve and/or restore brain function in the case of aging and injury.


Chronic stress is well known to impair the immune system but the brain is also very susceptible to stress, resulting in impaired memory and learning. The mechanisms behind these deleterious effects include alterations in certain immune proteins involved in stress and inflammatory processes such as cortisone, interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-a) that also impact learning and memory. Intermittent fasting (IF) has been well documented in animal studies to protect against stress-related impaired memory and learning.


Fasting can also prevent age-related atrophy of the brain along with additional molecular changes that include  proteins that affect mitochondrial function and enhance energy production and reduce inflammation, oxidative stress in the brain.


As a side note regarding improving cognitive function, aerobic exercise is also an important factor in preserving and improving brain functioning. Multiple studies have demonstrated improvements in cognitive performance in response to regular aerobic exercise. In one study, when the caloric intake of fifty normal elderly subjects was reduced by 30% for 3 months, their performance on memory tests improved significantly. In another study of 1820 adolescents, cognitive performance was significantly better in those who engaged in sports compared to those who were less active. MRI studies show that the size of several brain regions, including both gray and white matter, is increased by regular aerobic exercise but not by non-aerobic stretching and toning. Aerobic exercise results in greater functional efficiency of cognitive networks due to improved functional connectivity (neural plasticity) which correlates with improved performance in cognitive testing. Both ER and exercise can promote optimal brain function and resistance to age-related diseases via both overlapping and complementary mechanisms.


 (5) Energy Restriction (ER) – Improving sleep

While there does not appear to be a great deal of research availalbe that evaluates the benefit of sleep a small study published in 2003 evaluating  13 non-obese subjects (12 females, 1 male; age 41.2 +/- 13.4 years).  Compared to baseline, after a 7-day fasting period subjects reported a significant decrease in sleep arousals, a decrease in periodic leg movements (PLM) and a non-significant increase in REM sleep. Subjective sleep ratings showed a fasting-induced increase in global quality of sleep, daytime concentration, vigour and emotional balance. More research is needed.


 (6) Energy Restriction (ER) – Improving fatty liver disease

Reductions in fat, specifically visceral fat (surrounding the intra-abdominal organs) and liver fat stores are a goal of ER. Hepatic and visceral fat stores rapidly mobilise with marked ER as they are thought to be more sensitive to the fat-breakdown effects of catecholamines during negative energy balance than subcutaneous fat. Marked CER (>50% ER) is related to rapid decreases in hepatic fat in people with obesity. A 30% reduction in hepatic fat was reported after seven days of a 60%–70% CER in patients with type 2 diabetes. Unfortunately there are currently no human studies evaluating the long term or chronic effects of IER on hepatic and intra-abdominal fat stores. Reports of significant reductions in hepatic fat stores (−29%) after two days of ER and carbohydrate restriction in men and women with obesity, suggest reductions could occur during the repeated spells of restriction with IF/IER each week.


According to new research, short periods of restricted calorie intake change the genetic activity of liver cells. by activating a gene linked to the production of a particular protein called GADD45β (‘Growth Arrest and DNA Damage-inducible). GADD45β is responsible for repairing damaged DNA. and also modulating the  liver’s fatty acid absorption and normalizing the liver’s fat levels.


Similarly, low GADD45β levels in humans correlate to higher levels of both blood sugar and liver fat. But  researchers have concluded that fasting stresses liver cells to trigger the release of GADD45β. Whether fasting may represent an effective tool for the treatment of fatty liver remains unanswered but the theory is hopeful.


(7) Energy Restriction (ER) – Reducing Oxidative Stress and Cancer Risk

Excess fat and overnutrition are important causes of cancer. An increase in BMI of 5 is associated with a 20–52% greater risk of 13 cancers, including endometrial, gall bladder, renal, rectal, postmenopausal breast, pancreatic, thyroid, colon, and esophageal cancers; leukemia; multiple myeloma; non-Hodgkin lymphoma; and malignant melanoma.  Evidence indicates that weight reduction with energy restriction (ER) reduces the risk of breast cancer and possibly other forms of cancer.


Oxidative Stress and Antioxidant Activity

Oxidative stress is linked to the development of cancer and accelerated aging, with the prevailing hypothesis being that reactive oxygen species (ROS) production should be limited to reduce cellular damage. Recent research suggests that ROS production may be required to instigate mild cellular stress response, which in turn upregulates antioxidant pathways and lowers overall long-term oxidative stress. It has been proposed that engaging processes such as fasting that target pathways and molecules involved in removing cellular damage rather than ROS,  could be more effective in reducing diseases caused by oxidation and aging.


Oxidative Stress: IER vs CER

Recent reviews suggest that IER may be associated with greater disease prevention than CER due to increased cellular stress resistance, especially increased resistance to oxidative stress. This is thought to be due to the moderate stress of energy restriction increasing the production of cytoprotective, restorative proteins and antioxidant enzymes. The mechanism of this production is related to stimulation of the mitochondria, the intracellular organelle that produces cellular energy and manufactures antioxidants.



 (8) Energy Restriction (ER) – Reducing Depression

Dues to the fact that many depressed patients fail to tolerate or respond to available antidepressant therapies and medications, alternative means of treating depression are needed. Recently,
increasing amounts of research have demonstrated the benefits of ER on the neuroendocrine
system and in depression. Both basic and clinical investigations have demonstrated that short-term ER may be effective in depression. However, the effect of long-term caloric restriction is controversial, as it may result in long-term detrimental effects by inhibiting the function of the serotonin system and decreasing leptin levels.


 (9) Energy Restriction (ER) – Reducing Symptoms of Fibromyalgia

While studies evaluating the role of ER in treating fibromyalgia symptoms are limited, ER does appear to be improve the pain and fatigue associated with fibromyalgia. The likely mechanism of benefit lies in the fact that ER triggers a cellular response that stimulates mitochondrial production and biogenesis. Mitochondrial dysfunction has been implicated as a major feature of fibromyalgia, contributing to the widespread muscle pain, cognitive impairment and fatigue.


 (10) Energy Restriction (ER) – Reducing Chronic Pain and Inflammation

Transitioning from acute to chronic pain is a complex, maladaptive process that includes inflammation within  the central and peripheral nervous system. As noted above, ER results in cellular responses that include enhancement of mitochondrial function, including the production of cellular antioxidants and, additionally, pro-inflammatory hormones and cytokines are decreased while anti-inflammatory hormones and cytokines are increased. These cellular responses in turn reduce systemic oxication and inflammation which, at least in theory, should reduce both current pain and further progression of chronic pain.   While clinical studies that explore this theory are limited, emerging research does confirm the benefits of ER regarding a reductionn in chronic pain as well as improved sense of vitality.


It has been well established that structural and functional changes occur in the brain in response to chronic pain, particularly in regions involved in emotional and sensory processing. These changes in brain structure and function include a decrease in gray matter and white matter integrity, alterations in neurotransmitters, and a decrease in signaling from the brain, “descending inhibition,” that normally oppose pain signals ascending from the spinal cord to the brain. Current theoretical models of pain suggest that pre-existing individual vulnerabilities that interact with pain-related experiences associated with duration and intensity of pain, along with pain-related learning and memory give rise maladaptive changes in brain structure and function. Such changes in brain structure and function are referred to as neural plasticity and may be maladaptive and harmful or adaptative and beneficial.


Evidence confirms that the maladaptive alterations in the brain associated with chronic pain are modifiable and reversible with effective clinical interventions that focus on cognitive and behavioral techniques that allow for changing how pain is perceived. Interventions such as meditation, prayer and other “mindful exercises,” as well as self-hypnotic techniques allow for alterations in how one confronts the pain experience. Understanding how these interventions reduce pain is based on adaptive neural plasticity in which neural circuits, neurtransmitters and, eventually, structural changes in the brain itself  develop as a result of practiced and repetitive exercises in the thought processing related to these activities. In order to counteract the maladaptive plasticity associated with chronic pain, pairing pain treatment interventions with strategies that can increase neuroplasticity and optimize the brain’s ability to learn, adapt, and implement new information may improve treatment outcomes.


As noted above, energy restriction (ER) triggers mechanisms that enhance adaptive cellular responses and neuroplasticity (See above:  (4) Energy Restriction (ER) – Improving Cognitive Functioning). It stands to reason that engaging ER in the form, for example, of intermittent fasting will facilitate the adaptive changes associated, for example, with self-hypnosis techniques for reducing the experience of pain, resulting in enhanced results for controlling pain.


This model of incorporating ER with mindful exercises reflects what many of the major spiritual practices have taught for centuries, expressed in terms related to science rather than religion yet mirroring the same principles. It is important to stress that fasting in of itself will not likely reduce pain. It only becomes useful as a physiologic tool when coupled with the mimdful or spiritual exercise directed specifically at altering the pain experience. The combination of these processes become quite powerful techniques when engaged fully with commitment.


 (11) Energy Restriction (ER) – Reducing Nerve Damage and Injury

There is evidence that ER may protect against the development of neurodegenerative disorders including Alzheimers Disease and Parkinsons Disease. Furthermore, animal studies that evaluate ER in strokes show that ER promotes long-term recovery of function over a period of months. The mechanisms responsible for this include enhancement of adaptive cellular stress responses and neuroplasticity (See above:  (4) Energy Restriction (ER) – Improving Cognitive Functioning). In addition, by bolstering neuronal energetics, ketone bodies may contribute to the neuroprotective effects of ER.


  (12) Energy Restriction (ER) – Potentially Improving Lifespan

The health benefits of  energy restriction in early human clinical trials are supported by a century of animal research which has determined that energy restriction (ER) prevents age-related disease including tumours, cardiovascular disease, diabetes and dementia; retards aging-related functional decline; and increases lifespan. Recently, reearch has focused on intermittent energy restriction (IER) regarding the beneficial effects in healthy human aging. Several anti-aging mechanisms are proposed including reducing damaging chronic inflammation at molecular levels and modifiying  gene expression by effects on epigenetic chromatin and histone. While it is early in the understanding of ER’s effects on improving lifespan as the mysteries of aging still elude modern science, it nevertheless appears that incorporating some form of ER into one’s lifestyle would likely be beneficial.


Understanding the Mechanisms Behind the Benefits of Energy Restriction (ER)

Cellular damage that leads to chronic disease and cancer is believed to result from oxidative stress, the condition in which tissues including proteins, DNA and cell membranes are oxidized, or damaged, as the result of exposure to highly reactive agents known as reactive oxygen species (ROS) or reactive nitrogen species (RNS), also known as “free radicals.” These agents come from environmental exposure but are also formed in various cellular metabolic processes and are produced in greater abundance in a number or medical conditions including obesity.


Oxidative stress is linked to the development of chronic disease, cancer and accelerated aging, with the current prevailing theory being that reactive oxygen species (ROS) production should be limited to reduce cellular damage. However, recent research suggests that ROS production may be required to instigate mild cellular stress response, which in turn upregulates antioxidant pathways and lowers overall long-term oxidative stress. It has been proposed that engaging processes such as fasting that target pathways and molecules involved in removing cellular damage rather than ROS,  could be more effective in reducing diseases caused by oxidation and aging. In relation to this theory, although not related to fasting, this may be a mechanism for the benefit of NRF2 activators (See NRF2 Activators).


One outcome of ER is that it triggers adaptive cellular stress responses, which result in an enhanced ability to cope with more severe stress and counteract disease processes. These cellular mechanisms also protect cells from DNA damage and enhance apoptosis (recycling) of damaged cells, that may reduce the development of certain chronic diseases and prevent the formation and growth of cancers.


In summary, ER reduces nervous system accumulation of oxidatively damaged molecules and improves cellular bioenergetics by stimulating mitochondrial biogenesis, improves neural plasticity by enhancing neurotrophic factor signaling, and reduces inflammation. These neuroprotective mechanisms are supported by studies showing that ER diets boost levels of antioxidant defenses, neurotrophic factors (BDNF, PGC-1α and FGF2) and protein chaperones (HSP-70 and GRP-78), and reduce levels of pro- inflammatory cytokines (TNFα, IL-1β and IL-6).


Among the major effects of fasting relevant to aging and diseases are changes in the levels of IGF-1, IGFBP1, glucose, and insulin. Fasting for 3 or more days causes a 30% or more decrease in circulating insulin and glucose, as well as rapid decline in the levels of insulin- like growth factor 1 (IGF-1), the major growth factor  which together with insulin is associated with accelerated aging and cancer. In humans, five days of fasting causes an over 60% decrease in IGF-1and a 5-fold or higher increase in one of the principal IGF-1-inhibiting proteins: IGFBP1. This effect of fasting on IGF-1 is mostly due to protein restriction, and particularly to the restriction of essential amino acids, but is also supported by calorie restriction since the decrease in insulin levels during fasting promotes reduction in IGF-1. However, chronic calorie restriction alone does not lead to a decrease in IGF-1unless combined with protein restriction.

Understanding the Adaptive Responses to Energy Restriction (ER)

In humans and most mammals, the liver is the main storage reservoir of glucose, which is stored in the form of glycogen. Depending upon the level of one’s physical activity, 12 to 24 hours of fasting typically results in a 20% or greater decrease in serum glucose and depletion of the hepatic glycogen. This depletion of glucose and glycogen is accompanied by a switch to a metabolic mode in which glucose stored in muscles, fat-derived ketone bodies and free fatty acids are used as energy sources. Fat is broken down (lipolysis) and converted to ketones (ketogenesis) that are used as energy source, leading to a state of ketosis.


Whereas most tissues can utilize fatty acids for energy during prolonged periods of fasting, the brain relies on ketone bodies (β-hydroxybutyrate and acetoacetate) in addition to glucose for energy. During fasting, ketogenesis occurs in which ketone bodies are produced in the liver from fatty acids released into the bloodstream by fat cells, and also by the conversion of amino acids from the breakdown of muscle protein. Once liver glycogen stores are depleted, these ketone bodies and amino acids are converted into glucose, which is mostly utilized by the brain, and are themselves in turn used as energy sources by the rest of the body. This transition of energy source usage is referred to as ketosis. Depending on body weight and composition, this process allows the majority of human beings to survive 30 days or more  in the absence of any food.


Recommendations for Incorporating ER for Brain Health

Incorporating of intermittent energetic restricion into our daily and weekly schedules should be a guiding principle for achieving optimal brain health. Research strongly suggests that, if followed, a prescription of IER (and regular exercise) will improve the health and longevity of the brain and body. Individuals who are either overweight and sedentary or normal weight and active should engage in IER and regular vigorous exercise in order to improve their brain health and reduce their risk for neurodegenerative disorders.


Fasting regimens can be tailored for specific diseases as stand-alone or adjunct therapies. Results of initial trials of IF (fasting 2 days per week or every other day) in human subjects suggest that there is a critical transition period of 3 – 6 weeks during which time the brain and body adapt to the new eating pattern and mood is enhanced. Importantly, the various fasting approaches are likely to be more effective when combined with diets such as the mostly plant-based Mediterranean or Okinawa low protein diets (0.8 g protein/Kg of body weight), consistently associated with health and longevity.


There are many different variations on the general theme of IER and exercise that will result in improved health. The impact of engaging these changes in lifestyle on obesity and associated diseases, including neurodegenerative disorders such as Alzheimers, could be profound. There are many xamples of possible ER regimens that can be readily incorporated into work and family life schedules in ways that not only improve brain health, but also enhance productivity and leisure activities include:


Suggested examples of energy restriction (ER) regimens:

  1. Alternating days of fasting and “normal” eating, with a daily exercise period. For example, engage a twice weekly IER diet and consume only 500–600 calories on the fasting days.
  2. Eating only during a short time period each day (e.g., not eating breakfast or lunch) and exercising every other day.
  3. Eating in the morning and late afternoon/ evening, and exercising at midday.


Suggested means of enhancing the benefitx associated with energy restriction (ER) regimens:

  1. Engage a preferred form of meditative activity, prayer or self-hypnosis technique, preferably daily, as a means of facilitating changes in the brain and nervous system to reduce the chronic pain experience.
  2. Incorporate a healthy, anti-inflammatory diet such as the Mediterranean or Okinawan diets.
  3. Include nutriceutical supplements that may boost neural plastic change, including Niacel (nicotinamide riboside) as a mitochondrial stimulant and NRF2 activators such as Meriva (curcumin), green tea and Polyresveratrol.


While it is often assumed that the beneficial effects of ER on health and longevity requires an overall reduction in caloric intake. However, emerging research suggests that IER without an overall reduction in calorie intake also improves health and resistance to diseases. Beneficial health effects of IER occured in a study of healthy young men (BMI of 25) after 15 days of alternate day fasting: their whole-body glucose uptake rates increased significantly (increased insulin sensitivity), levels of plasma ketone bodies and adiponectin were elevated, all of which occurred without a significant decrease in body weight.


ER, especially IER, can be performed with a minimal decrease in overall calorie intake if the refeeding period in which subjects overeat is considered. Thus, fasting cycles provide a much more feasible strategy to achieve the beneficial effects of CR, and possibly stronger effects, without the burden of chronic underfeeding and some of the potentially adverse effects associated with weight loss in underweight individuals. In fact, subjects who are moderately overweight (BMI of 25–30) in later life may have reduced overall mortality risk compared to subjects of normal weight. It is necessary to differentiate between ER with the purpose to include weight loss versus the use of ER to achieve other health benefits.


Although extreme dietary interventions during old age may continue to protect from age-related diseases, they could have detrimental effects on the immune system and the ability to respond to certain infectious diseases, wounds and other challenges. However, ER designed to avoid weight loss and maximize nourishment have the potential to have beneficial effects on infectious diseases, wounds and other insults even in the very old.


The timing of when one eats may also play a significant role in this. In one study in mice, one group of mice was provided with a high caloric diet eating as desired over 24 hours, whereas another group was provided the same diet for only during the 8 hour period in which they were active. Although the mice in both groups ate the same amount of food, the mice who ate in the 8 hour period only maintained a much lower body weight, and had reduced amounts of body fat. It may be that the circadian regulation of cellular energy metabolism affects body weight control in ways not yet understood.


Resources for Nutritional Information

This is my favorite online resource for nutritional information. It provides excellent breakdowns of the nutrional value of natural foods, raw and cooked, as well as commercial food products. It offers a web-based app that allows you to track and analyze your diet and monitor your exercise. It has a wealth of educational information on topics from food additives, glycemic index, food processing, individual nutrients and pretty much anything of interest to the person motivated to learn more about diet and nutrition. There are even recipes!


Nutrition.gov provides easy access to vetted food and nutrition information from across the federal government. It serves as a gateway to reliable information on nutrition, healthy eating, physical activity, and food safety for consumers.


Providing science-based dietary guidance is critical to enhance the public’s ability to make healthy choices in the effort to reduce obesity and other food related diseases. Since dietary needs change throughout the lifespan, specialized nutrition information is provided about infants, children, teens, adult women and men, and seniors.


Users can find practical information on healthy eating, dietary supplements, fitness and how to keep food safe. The site is kept fresh with the latest news and features links to interesting sites.




Educational Resources:






Overweight and Obesity

  1. Association of All-Cause Mortality With Overweight and Obesity Using Standard Body Mass Index Categories – A Systematic Review and Meta-analysis – 2013

Fasting – Overviews

  1. Fasting – Molecular Mechanisms and Clinical Applications – 2014
  2. Incorporation of fasting therapy in an integrative medicine ward- evaluation of outcome, safety, and effects on lifest
  3. Intermittent fasting could ameliorate cognitive function against distress by regulation of inflammatory response pathway – 2017
  4. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers – a randomised trial in young overweight women – 2011
  5. Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage – 2017
  6. Potential Benefits and Harms of Intermittent Energy Restriction and Intermittent Fasting Amongst Obese, Overweight and Normal Weight Subjects-A Narrative Review of Human and Animal Evidence – 2017
  7. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers – a randomized trial in young overweight women – 2011
  8. Efficacy of fasting calorie restriction on quality of life among aging men. – PubMed – NCBI
  9. Recent advances in calorie restriction research on aging. – PubMed – NCBI
  10. Energy Intake and Exercise as Determinants of Brain Health and Vulnerability to Injury and Disease – 2012
  11. Food restriction markedly increases dopamine D2 receptor (D2R) in a rat model of obesity as assessed with in-vivo muPET imaging ([11C] raclopride) … – PubMed – NCBI


Fasting – Caloric Restriction

  1. Caloric restriction: from soup to nuts. – PubMed – NCBI
  2. Calorie restriction – Wikipedia Calorie restriction increases life span: a molecular mechanism. – PubMed – NCBI
  3. Calorie restriction increases muscle mitochondrial biogenesis in healthy humans. – 2007
  4. Preview of “Changes of serum leptin and endocrine and metabolic parameters after 7 days of energy restriction in men and women. – PubMed – NCBI”
  5. Efficacy of fasting calorie restriction on quality of life among aging men. – PubMed – NCBI


Fasting – Cancer

  1. Could Intermittent Energy Restriction and Intermittent Fasting Reduce Rates of Cancer in Obese, Overweight, and Normal-Weight Subjects? A Summary of Evidence -2016


Fasting – Cardiovascular Health

  1. Alternate day fasting with a high-fat diet produces similar weight loss. – PubMed – NCBI


Fasting – Cognitive Functioning

  1. Intermittent fasting could ameliorate cognitive function against distress by regulation of inflammatory response pathway – 2017


Fasting – Depression

  1. The Effects of Calorie Restriction in Depression and Potential Mechanisms – 2015
  2. Diet and cognition – Data, theory, and some solutions from the playbook of psychology – 2016


Fasting – Fatty Liver

  1. Fasting-induced liver GADD45b restrains hepatic fatty acid uptake and improves metabolic health – 2016
  2. Manifestations of Fasting-Induced Fatty Liver and Rapid Recovery from Steatosis in Voles Fed Lard or Flaxseed Oil Lipids – 2013


Fasting – Fibromyalgia

  1. Calorie restriction increases muscle mitochondrial biogenesis in healthy humans. – 2007
  2. Mediterranean diet or extended fasting’s influence on changing the intestinal microflora, immunoglobulin A secretion and clinical outcome in patients with rheumatoid arthritis and fibromyalgia – 2005
  3. In-Patient Treatment of Fibromyalgia – A Controlled Nonrandomized Comparison of Conventional Medicine versus Integrative Medicine including Fasting Therapy – 2013


Fasting – Oxidative Stress

  1. Alternate Day Calorie Restriction Improves Clinical Findings and Reduces Markers of Oxidative Stress and Inflammation in Overweight Adults with Moderate Asthma – 2007


Fasting – Pain

  1. Fasting induces an anti-inflammatory effect on the neuroimmune system which a high-fat diet prevents – 2011
  2. Increasing Neuroplasticity to Bolster Chronic Pain Treatment – A Role for Intermittent Fasting and Glucose Administration? – 2016
  3. Fasting induces IL-1 resistance and free-fatty acid-mediated up-regulation of IL-1R2 and IL-1RA – 2014
  4. Prolonged fasting as a method of mood enhancement in chronic pain syndromes- a review of clinical evidence and mechanisms
  5. The short-term effects of fasting on the neuroendocrine system in patients with chronic pain syndromes. – PubMed – NCBI
  6. Modulation of endogenous opiate production – effect of fasting
  7. Alternate Day Calorie Restriction Improves Clinical Findings and Reduces Markers of Oxidative Stress and Inflammation in Overweight Adults with Moderate Asthma – 2007
  8. Prolonged fasting in patients with chronic pain syndromes leads to late mood-enhancement not related to weight loss and fasting-induced leptin depl… – PubMed – NCBI
  9. [Short-term therapeutic fasting in the treatment of chronic pain and fatigue syndromes–well-being and side effects 2002


Fasting – Rheumatoid Arthritis

  1. Managing Rheumatoid Arthritis with Dietary Interventions – 2017
  2. Controlled trial of fasting and one-year vegetarian diet in rheumatoid arthritis – 1991
  3. Fasting followed by vegetarian diet in patients with rheumatoid arthritis – a systematic review – 2001


Fasting – Sleep

  1. Effects of short-term modified fasting on sleep patterns and daytime vigilance in non-obese subjects- results of a pilot study.


Fasting – Weight Loss

  1. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers – a randomised trial in young overweight women – 2011
  2. Intermittent fasting interventions for the treatment of overweight and obesity in adults aged 18 years and over: a systematic review protocol. – PubMed – NCBI
  3. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Cli… – PubMed – NCBI
  4. Alternate day fasting with a high-fat diet produces similar weight loss. – PubMed – NCBI
  5. Effects of weight loss via high fat vs. low fat alternate day fasting diets on free fatty acid profiles – 2015
  6. Alternate-day versus daily energy restriction diets – which is more effective for weight loss? A systematic review and meta-analysis – 2016
  7. Alternate day fasting for weight loss in normal weight and overweight subjects – 2013

Emphasis on Education


Accurate Clinic promotes patient education as the foundation of it’s medical care. In Dr. Ehlenberger’s integrative approach to patient care, including conventional and complementary and alternative medical (CAM) treatments, he may encourage or provide advice about the use of supplements. However, the specifics of choice of supplement, dosing and duration of treatment should be individualized through discussion with Dr. Ehlenberger. The following information and reference articles are presented to provide the reader with some of the latest research to facilitate evidence-based, informed decisions regarding the use of conventional as well as CAM treatments.


For medical-legal reasons, access to these links is limited to patients enrolled in an Accurate Clinic medical program.


Should you wish more information regarding any of the subjects listed – or not listed –  here, please contact Dr. Ehlenberger. He has literally thousands of published articles to share on hundreds of topics associated with pain management, weight loss, nutrition, addiction recovery and emergency medicine. It would take years for you to read them, as it did him.


For more information, please contact Accurate Clinic.


Supplements recommended by Dr. Ehlenberger may be purchased commercially online or at Accurate Clinic.

Please read about our statement regarding the sale of products recommended by Dr. Ehlenberger.

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