While most people plan to take up intermittent fasting for weight loss, it’s not just for weight watchers. It offers a multitude of health benefits that gives most of us reasons to give it a go!
Unlike a constant low-calorie diet or an extreme diet that requires you to cut out certain food groups like carbohydrates altogether, intermittent fasting intersperses normal eating with a meal skipped every now and again. It could also mean a day or two of fasting in between regular days.
And fasting does not have to be an uphill task. In fact, when you go to sleep every night, you are in effect allowing your body to fast for the 8 hours that you sleep and until you have breakfast. Recent research has found that intermittent fasting offers a range of health benefits. So what are these benefits?
1. Fat Burning And Weight Loss
Increased fat burning is the most obvious benefit of intermittent fasting. When you go on a fast, your body’s glucose and insulin levels drop significantly. In the absence of glucose, the body turns to fat burning. One small study of non-obese men and women found that fat oxidation rates increased after alternate-day fasting.1
Human growth hormone levels also rise significantly after fasting.2 This hormone is said to help with fat burning as well as muscle gain. Research has shown that it can increase lean body mass and bring down fat mass in healthy seniors of both genders.3
Intermittent fasting can boost
- Basal metabolic rate by 3.6%
- Resting energy expenditure by 14%
- Fat loss by 4%–7%
- Weight loss by 3%–8%
Inevitably, this leads to weight loss. First, since you’re eating fewer meals, it reduces your daily calorie consumption. Second, it increases your basal metabolism – the rate at which you burn calories when at rest. In one small study, researchers found that fasting completely (starvation) for 48 hours caused basal metabolism of the subjects to rise by about 3.6% on an average.4 In another piece of research, the metabolic rate, as measured by resting energy expenditure, rose by around 14% on the first day of a multi-day (84-hour) fast. This change in metabolic rate could be because, as mentioned earlier, fasting enhances the functioning of growth hormones. It also increases the amount of the hormone norepinephrine, which encourages fat burning, and all of these factors play a role in the breakdown of body fat.
Hence, intermittent fasting may allow you to benefit from this raised metabolic rate to burn off calories – without having to fast for long periods of time.5 In fact, one study conducted on type 2 diabetics found that intermittent fasting can help people lose up to 3–8% of body weight and 4–7% of fat from their waist over the course of 3–24 weeks!6
2. Improves Diabetes Symptoms
Diabetics could benefit from intermittent fasting, provided they do it under medical supervision. Intermittent fasting has been found to:
- Hike insulin sensitivity: Diabetics typically suffer from low insulin sensitivity, which leads to high insulin as well as glucose levels in the blood. Excess insulin is also harmful in the long run. In a study, male participants who fasted intermittently noted a reduction in their blood sugar levels by 3–6% and in their fasting insulin levels by 20–31%.7
- Regenerate beta cells in the pancreas: Type 1 diabetics have very few insulin-producing beta cells in their pancreas, which is what causes the diabetes. Mice study has shown that fasting intermittently can even help regenerate the insulin-producing beta cells in the pancreas.8 9
- Prevent diabetes complications: Yet another study found that this form of fasting prevented kidney damage, a common diabetes complication.10
Remember, the key is to fast “intermittently.” If you constantly go on a fast, you may actually end up with more abdominal fat as a result of impaired morning glucose tolerance and delayed insulin response.11
3. Reduces Inflammation
Inflammation is the body’s natural (immune) response to an injury and foreign invaders (such as viruses and bacteria). However, chronic inflammation has been connected to a number of illnesses that plague people today – such as arthritis, diabetes, heart disease, Alzheimer’s, and cancer.12
Besides lowering inflammation, by maintaining brain structure and function, intermittent fasting is believed to ease chronic pain.13
Research indicates that when you fast, your body releases ghrelin, the hunger hormone, which is known to lower inflammation and aid in the treatment of any diseases associated with it.14 In addition to this, intermittent fasting reduces the number of inflammatory proteins called cytokines.15 And considering how fasting for just one meal can make a difference, intermittent fasting is often recommended for people with inflammatory disorders.16
4. Prevents Heart Diseases
Alternate-day fasting has been found to help reduce levels of triglycerides while improving levels of good high-density lipoprotein (HDL) cholesterol. Both these factors are essential in protecting the heart. In addition to this, intermittent fasting lowers blood pressure and resting heart rate in the same way as intensive exercise does. While a stable blood pressure promotes cardiovascular health, a lower heart rate at rest indicates better heart function and cardiovascular fitness.17
5. Lowers Risk Of Metabolic Diseases
Research on animal test subjects shows that time-restricted feeding can help prevent metabolic diseases like liver disease and obesity even on a high-fat diet. This could be because fasting improves cell signaling (communication between cells) and increases metabolism. It comes as no surprise then that experts have been recommending intermittent fasting to individuals with metabolic diseases.18
6. Improves Digestion
Fasting boosts the production of hormone ghrelin, the hunger hormone. This hormone plays an important role in digestion and gut health. It prepares the body for nutrient absorption by secreting gastric acid and stimulating the movements of fluids in the gastrointestinal system.19 This could be why fasting has been shown to improve symptoms like abdominal pain, diarrhea, and nausea caused by colitis, ischemia, and irritable bowel syndrome.20 21
7. May Improve Sleep
According to a source, not eating anything for 16 hours before waking up could improve sleep quality.
If you tend to toss and turn at night and wake up every morning extremely groggy and sleep deprived, you might benefit from intermittent fasting. One study states that it improves the quality of sleep and reduces the number of times one wakes up in the middle of the night.22 However, other studies note that people who practice intermittent fasting may experience sleeplessness and daytime sleepiness as a side effect. Since there are mixed results on the effects of intermittent fasting on sleep, it’s best to consult a doctor first, especially if you are under treatment for insomnia.23
8. Promotes Skin Health
Studies suggest that intermittent fasting may not only increase the pace of wound-healing but also reduce allergic reactions (on the skin) and acne.
There is some evidence that links intermittent fasting to faster wound healing.24 However, this isn’t the only benefit that this form of fasting brings with it. Studies state that it can aid in alleviating contact dermatitis and chronic urticaria – allergic reactions on the skin.25 It is believed that fasting intermittently can also reduce acne breakouts, but there isn’t enough research to back this up.
9. Boosts Mood And Motivation
If you’ve been feeling low of late, you could try intermittent fasting. Since it improves sleep, this form of fasting is also linked to an increase in motivation and better daytime performance in general tasks.26 Consuming fewer calories and fasting intermittently has also shown to lower depression and improve mood in aging men. This could be due to the fact that intermittent fasting boosts ghrelin, which is linked to the hippocampus, the part of the brain that is responsible for emotion.27
10. Promotes Brain Health
Studies have noted that learning might be the best when one fasts during the day because this is when ghrelin levels are high. Ghrelin helps regenerate brain cells.28
Studies have found that intermittent fasting can also promote brain health. For instance, this form of fasting could help protect you against the effects of genetic and environmental factors that play a role in the aging of the brain and any associated frailty such as muscle loss.29 This form of fasting is also associated with the growth of the hippocampus, the part of the brain that is responsible for emotion and memory.30
Besides this, a study conducted on mice noted that regular intermittent fasting improved their memory and learning.31
11. May Prevent Alzheimer’s, Parkinson’s, And Huntington’s Disease
Fasting has been seen to boost the production of a protein called BDNF, which in turn promotes the production of neurons. This may counter nerve-degenerating diseases like Alzheimer’s.
Neurodegenerative diseases don’t have a cure, which is why preventing them is critical. Scientists link the overactivity of nerves to degenerating diseases like Parkinson’s, Alzheimer’s, and Huntington’s disease.32 Preliminary studies state that intermittent fasting may:
- Slow down the onset of Parkinson’s disease by increasing the production of ghrelin, the hunger hormone. This hormone increases the concentration of dopamine in a part of the brain where the decline of dopamine cells causes Parkinson’s disease.33
- Delay the onset of Alzheimer’s disease or reduce its severity.34 Daily short-term fasts improved the symptoms of Alzheimer’s in 9 out of 10 patients.35
- Delay the onset of Huntington’s disease and increase the life span of patients.36
12. Alleviates Asthma Symptoms
You could alleviate asthma symptoms by just skipping one meal of 400–500 calories every alternate day.
As stated earlier, intermittent fasting reduces inflammation and oxidative stress in the body. And this, in turn, can improve the symptoms of asthma, especially in people who are overweight. This applies to those with milder forms of asthma. Researchers have found that skipping just one meal of about 400–500 calories every other day could reduce difficulties in breathing.37
13. Fights Infections
Fasting boosts the production of neutrophils, a type of white blood cells, and immunoglobulin A, an antibody that plays a critical role in immune function. This helps your body fight off infections by bacteria like Salmonella.38 39 Intermittent fasting has also shown promise in preventing damage to the brain during the course of an infection.40
14. May Improve Symptoms Of Autoimmune Diseases
Fasting intermittently is believed to lower the autoimmune response and promote the regeneration of immune cells.41 A study has shown that this form of fasting may reverse the symptoms of multiple sclerosis, lupus, and vasculitis.42 Further studies are required to establish intermittent fasting as a mode of managing autoimmune diseases.
15. Prevents Cancer
Studies have shown that fasting every alternate day or fasting for longer intervals during the night may prevent cancer.
We already know that intermittent fasting lowers blood glucose levels. Recent studies have shown that it also lowers levels of the hormone IGF-1 (insulin-like growth factor) in the body. These together contribute to a lower risk of cancer.43 Studies conducted on animals have also noted a lower incidence of cancer after fasting every alternate day.44 To add to this, reducing one’s caloric intake and fasting for longer intervals during the night has been found to reduce the risk of breast cancer.45
16. Extends Lifespan
Intermittent fasting may extend your lifespan by up to 30%.
Considering the range of health benefits that have already been listed, it’s no surprise that intermittent fasting is known to increase one’s lifespan. For one, it delays aging by protecting the body from disease. It also works on the biological pathways that prolong the health span of the nervous system. Besides this, intermittent fasting boosts the body’s stress resistance, which increases longevity.46 47 Studies conducted on rats found that those that fasted regularly lived 83% longer than rats who didn’t.48 Other studies conclude that intermittent fasting can increase a person’s lifespan by up to 30%.49
Choose Among The 5 Types Of Intermittent Fasting
- 16:8 – Fast for 16 hours, eat all you can in 8 hours.
- 5:2 – Fast for 2 days a week, eat for 5 days.
- Alternate-day – Fast every alternate day.
- Warrior diet – Fast during the day, eat at night.
- Eat stop eat – Fast for 24 hours once or twice a week.
But Take Caution! Intermittent Fasting Is NOT For Everyone
Fasting of any kind is best undertaken under the guidance of a qualified dietician or nutritionist who can help you with your meal planning. Even something as seemingly harmless as intermittent fasting that involves skipping just one meal now and again could be dangerous for some people. Here are some instances where fasting without supervision is not a good idea:50
- If you are pregnant
- If you are diabetic or have insulin resistance or other blood sugar regulation problems
- If you have any kind of eating disorder
- If you don’t sleep well
- If you have any other health problem that could endanger your life or worsen your condition if you skipped meals or didn’t eat at regular intervals
- If you are not an adult – children with growing bodies have different nutritional needs and more active lifestyles than most adults. Intermittent fasting is probably not a good idea. If it is something required for religious reasons, it is best done with utmost care and with careful planning and under the guidance and with the consent of their parents.
If you fall under any of the above categories, it might be best to avoid intermittent fasting or consult a professional before taking it up.
|↑1||Heilbronn, Leonie K., Steven R. Smith, Corby K. Martin, Stephen D. Anton, and Eric Ravussin. “Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism.” The American journal of clinical nutrition 81, no. 1 (2005): 69-73.|
|↑2||Ho, Klan Y., Johannes D. Veldhuis, Michael L. Johnson, R. Furlanetto, William S. Evans, K. G. Alberti, and M. O. Thorner. “Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man.” Journal of Clinical Investigation 81, no. 4 (1988): 968.|
|↑3||Blackman, Marc R., John D. Sorkin, Thomas Münzer, Michele F. Bellantoni, Jan Busby-Whitehead, Thomas E. Stevens, Jocelyn Jayme et al. “Growth hormone and sex steroid administration in healthy aged women and men: a randomized controlled trial.” Jama 288, no. 18 (2002): 2282-2292.|
|↑4||Mansell, P. I., I. W. Fellows, and I. A. Macdonald. “Enhanced thermogenic response to epinephrine after 48-h starvation in humans.” American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 258, no. 1 (1990): R87-R93.|
|↑5||Zauner, Christian, Bruno Schneeweiss, Alexander Kranz, Christian Madl, Klaus Ratheiser, Ludwig Kramer, Erich Roth, Barbara Schneider, and Kurt Lenz. “Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine.” The American journal of clinical nutrition 71, no. 6 (2000): 1511-1515.|
|↑6, ↑7||Barnosky, Adrienne R., Kristin K. Hoddy, Terry G. Unterman, and Krista A. Varady. “Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings.” Translational Research 164, no. 4 (2014): 302-311.|
|↑8||Prediabetes & Insulin Resistance. National Institute Of Diabetes And Digestive And Kidney Diseases.|
|↑9||Fasting diet may help regenerate a diabetic pancreas. National Health Service.|
|↑10||Tikoo, Kulbhushan, Durga Nand Tripathi, Dhiraj G. Kabra, Vikram Sharma, and Anil Bhanudas Gaikwad. “Intermittent fasting prevents the progression of type I diabetic nephropathy in rats and changes the expression of Sir2 and p53.” FEBS letters 581, no. 5 (2007): 1071-1078.|
|↑11||Carlson, Olga, Bronwen Martin, Kim S. Stote, Erin Golden, Stuart Maudsley, Samer S. Najjar, Luigi Ferrucci et al. “Impact of reduced meal frequency without caloric restriction on glucose regulation in healthy, normal-weight middle-aged men and women.” Metabolism 56, no. 12 (2007): 1729-1734.|
|↑12||Foods that fight inflammation. Harvard Health Publications.|
|↑13||Sibille, Kimberly T., Felix Bartsch, Divya Reddy, Roger B. Fillingim, and Andreas Keil. “Increasing neuroplasticity to bolster chronic pain treatment: a role for intermittent fasting and glucose administration?.” The Journal of Pain 17, no. 3 (2016): 275-281.|
|↑14||Baatar, Dolgor, Kalpesh Patel, and Dennis D. Taub. “The effects of ghrelin on inflammation and the immune system.” Molecular and cellular endocrinology 340, no. 1 (2011): 44-58.|
|↑15||Aly, Salah Mesalhy. “Role of intermittent fasting on improving health and reducing diseases.” International journal of health sciences 8, no. 3 (2014).|
|↑16||Genetic switch turned on during fasting helps stop inflammation. Salk Institute.|
|↑17, ↑49||Collier, Roger. “Intermittent fasting: the next big weight loss fad.” (2013): E321-E322.|
|↑18||Hatori, Megumi, Christopher Vollmers, Amir Zarrinpar, Luciano DiTacchio, Eric A. Bushong, Shubhroz Gill, Mathias Leblanc et al. “Time-restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high-fat diet.” Cell metabolism 15, no. 6 (2012): 848-860.|
|↑19||Schwartz, Michael W., Stephen C. Woods, Daniel Porte Jr, Randy J. Seeley, and Denis G. Baskin. “Central nervous system control of food intake.” Nature 404, no. 6778 (2000): 661.|
|↑20||Kanazawa, Motoyori, and Shin Fukudo. “Effects of fasting therapy on irritable bowel syndrome.” International journal of behavioral medicine 13, no. 3 (2006): 214-220.|
|↑21||Pereira, Jéssica Aparecida da Silva, Felipe Corrêa da Silva, and Pedro Manoel Mendes de Moraes-Vieira. “The Impact of Ghrelin in Metabolic Diseases: An Immune Perspective.” Journal of diabetes research 2017 (2017).|
|↑22||Michalsen, A., F. Schlegel, A. Rodenbeck, R. Lüdtke, G. Huether, H. Teschler, and G. J. Dobos. “Effects of short-term modified fasting on sleep patterns and daytime vigilance in non-obese subjects: results of a pilot study.” Annals of nutrition and metabolism 47, no. 5 (2003): 194-200.|
|↑23||News analysis: Does the 5:2 fast diet work? National Health Services.|
|↑24||Hayati, Farzad, Mohsen Maleki, Maryam Pourmohammad, Kamran Sardari, Mehrdad Mohri, and Amir Afkhami. “Influence of short-term, repeated fasting on the skin wound healing of female mice.” Wounds 23, no. 2 (2011): 38.|
|↑25||Okamoto, Osamu, Isamu Murakami, Satoshi Itami, and Susumu Takayasu. “Fasting diet therapy for chronic urticaria: report of a case.” The Journal of dermatology 19, no. 7 (1992): 428-431.|
|↑26, ↑30, ↑33, ↑36, ↑46||Martin, Bronwen, Mark P. Mattson, and Stuart Maudsley. “Caloric restriction and intermittent fasting: two potential diets for successful brain aging.” Ageing research reviews 5, no. 3 (2006): 332-353.|
|↑27||Hussin, N. M., Suzana Shahar, N. I. M. F. Teng, W. Z. W. Ngah, and S. K. Das. “Efficacy of fasting and calorie restriction (FCR) on mood and depression among aging men.” The journal of nutrition, health & aging 17, no. 8 (2013): 674-680.|
|↑28||Powell, Kendall. “Hungry for better memory.” (2006): 787b-787b.|
|↑29||Tajes, M., J. Gutierrez-Cuesta, J. Folch, D. Ortuño-Sahagun, E. Verdaguer, A. Jiménez, F. Junyent, A. Lau, A. Camins, and M. Pallàs. “Neuroprotective role of intermittent fasting in senescence-accelerated mice P8 (SAMP8).” Experimental gerontology 45, no. 9 (2010): 702-710.|
|↑31||Kojima, Nobuhiko, and Tomoaki Shirao. “Synaptic dysfunction and disruption of postsynaptic drebrin–actin complex: a study of neurological disorders accompanied by cognitive deficits.” Neuroscience research 58, no. 1 (2007): 1-5.|
|↑32||How Fasting Allows The Brain To Recharge Itself. Duke Science and Society.|
|↑34||Halagappa, Veerendra Kumar Madala, Zhihong Guo, Michelle Pearson, Yasuji Matsuoka, Roy G. Cutler, Frank M. LaFerla, and Mark P. Mattson. “Intermittent fasting and caloric restriction ameliorate age-related behavioral deficits in the triple-transgenic mouse model of Alzheimer’s disease.” Neurobiology of disease 26, no. 1 (2007): 212-220.|
|↑35||Bredesen, Dale E. “Reversal of cognitive decline: A novel therapeutic program.” Aging (Albany NY) 6, no. 9 (2014): 707.|
|↑37||Johnson, James B., Warren Summer, Roy G. Cutler, Bronwen Martin, Dong-Hoon Hyun, Vishwa D. Dixit, Michelle Pearson et al. “Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma.” Free Radical Biology and Medicine 42, no. 5 (2007): 665-674.|
|↑38||Godínez‐Victoria, Marycarmen, Rafael Campos‐Rodriguez, V. Rivera‐Aguilar, Eleazar Lara‐Padilla, J. Pacheco‐Yepez, Rosa Adriana Jarillo‐Luna, and M. E. Drago‐Serrano. “Intermittent Fasting Promotes Bacterial Clearance and Intestinal IgA Production in Salmonella typhimurium‐Infected Mice.” Scandinavian journal of immunology 79, no. 5 (2014): 315-324.|
|↑39||Adawi, Mohammad, Abdulla Watad, Stav Brown, Khadija Aazza, Hicham Aazza, Mohamed Zouhir, Kassem Sharif et al. “Ramadan Fasting exerts immunomodulatory effects: insights from a Systematic Review.” Frontiers in immunology 8 (2017).|
|↑40||Vasconcelos, Andrea R., Lidia M. Yshii, Tania A. Viel, Hudson S. Buck, Mark P. Mattson, Cristoforo Scavone, and Elisa M. Kawamoto. “Intermittent fasting attenuates lipopolysaccharide-induced neuroinflammation and memory impairment.” Journal of neuroinflammation 11, no. 1 (2014): 85.|
|↑41||Choi, In Young, Laura Piccio, Patra Childress, Bryan Bollman, Arko Ghosh, Sebastian Brandhorst, Jorge Suarez et al. “A diet mimicking fasting promotes regeneration and reduces autoimmunity and multiple sclerosis symptoms.” Cell reports 15, no. 10 (2016): 2136-2146.|
|↑42||Liu, Yaoyang, Yiyun Yu, Giuseppe Matarese, and Antonio La Cava. “Cutting edge: fasting-induced hypoleptinemia expands functional regulatory T cells in systemic lupus erythematosus.” The Journal of Immunology 188, no. 5 (2012): 2070-2073.|
|↑43||Rothschild, Jeff, Kristin K. Hoddy, Pera Jambazian, and Krista A. Varady. “Time‐restricted feeding and risk of metabolic disease: a review of human and animal studies.” Nutrition reviews 72, no. 5 (2014): 308-318.|
|↑44||Varady, Krista A., and Marc K. Hellerstein. “Alternate-day fasting and chronic disease prevention: a review of human and animal trials.” The American journal of clinical nutrition 86, no. 1 (2007): 7-13.|
|↑45||Marinac, Catherine R., Dorothy D. Sears, Loki Natarajan, Linda C. Gallo, Caitlin I. Breen, and Ruth E. Patterson. “Frequency and circadian timing of eating may influence biomarkers of inflammation and insulin resistance associated with breast cancer risk.” PloS one 10, no. 8 (2015): e0136240.|
|↑47||Amigo, Ignacio, and Alicia J. Kowaltowski. “Dietary restriction in cerebral bioenergetics and redox state.” Redox biology 2 (2014): 296-304.|
|↑48||Goodrick, Charles L., Donald K. Ingram, Mark A. Reynolds, John R. Freeman, and Nancy L. Cider. “Effects of intermittent feeding upon growth and lifespan in rats.” Gerontology 28, no. 4 (1982): 233-241.|
|↑50||News analysis: Does the 5:2 fast diet work?. National Health Service.|