Fasting is a tradition very commonly seen in our country. Although we have varied cultures, religions and beliefs, fasting is done in every household at one time or the other. It is the oldest and an extremely powerful dietary intervention. It is basically the voluntary withholding of food and/or water for the purpose of health and spiritual well-being for a definite period of time usually ranging between 12 hours- 1 month. Scientifically fasting begins about 3 hours after the last meal intake. It differs from starvation as starvation is involuntary and uncontrolled chronic nutritional deficiency. Caloric restriction is the state wherein one reduces the caloric intake chronically by about 20-40% but the meal frequency is maintained.
Belief in fasting :
Hindus practice fasting on certain days of the week as per their religious faith, with each day fast having a certain belief and a different way of conducting it. It ranges from not eating anything, to having one meal per day, or avoiding whole grains to eating only fruits for the entire day(Avoiding high glycemic index food). Jainism holds the strictest of the fasts. Their fasts include not eating/drinking anything for 10 whole days followed by a celebration for one is believed to have successfully gained a control over their senses and temptations. Many Jains also do fasting on a daily basis where they do not have food/water from sunset to next day sunrise. Buddhist monks stop eating after noon every day to be able to practice their meditation better. Muslims practice fasting from dawn to dusk during their holy month of Ramadan. Similarly, there are various other faiths incorporating fasting as a tool for their well-being in one form or the other.
Body metabolism in fasting: Body usually enters in the fasting mode about 2-4 hours after the last meal when there is a dip in the blood glucose levels. This leads to a decrease in insulin and an increase in glucagon, epinephrine and norepinephrine levels that cause glycogenolysis. About 24 hours later, the body begins gluconeogenesis(wasting-substrate come from muscle, collagen, liver, tendon etc). After about 3 days of fasting, the body’s main store of glycogen in the liver and muscles are completely exhausted when it begins to perform lipolysis, breaking fats from the tissues and causing beta-oxidation of fatty acids for the production of energy. When the fatty acids increase, Ketone bodies production begins. At this point, the brain derives 30% of its energy from ketone bodies, and on the fourth day its increased to 75%. When the ketone bodies reach levels of 5-7 mM, its use in the brain and muscle stops. Now autophagy begins wherein cells break down their critical molecules and proteins to release amino acids that are utilized for gluconeogenesis constituting the final stage of fasting.
Intermittent fasting can be done as per the individual’s tolerance level. One of the most popular methods is the 5:2 fasting made popular by Dr Michael Mosley where one has 5 eating days where he eats normally and 2 fasting days. On the fasting days, he is allowed to have 500 Cals either spread out or in a single meal. This produces best results not only for weight loss, but also helps in mood elevation, and greater physical well-being.
Other kinds of fast include-:
- The Navratri Diet- Navratri literally means 9 nights and is celebrated amongst Hindus in the honour of Goddess Durga. It is celebrated twice in a year–once during spring (vasant), and once during fall (sharadiya). This is the period of transition in the seasons and makes our bodies fall prey to a number of diseases. Hence, fasting during this time boosts the immunity, causes weight loss, detoxifies the body, and brings positive thinking. It encourages use of traditional flours and grains such as buckwheat (kuttu) flour, water chestnut (singhara) flour, amaranth (rajgira) flour, and millet (saame) flour which are all gluten-free and low glycemic index foods. Rock salt is used at this time which is good for blood pressure and helps absorb minerals better than common salt. One restricts intake of food items such as coffee, mustard, hot spices etc. that can induce acidity of bloating sensation in the stomach. Consumption of a lot of fluids and eating fresh fruits are advised that help the body to flush out all the toxins
- Atkins diet- Devised by Robert Atkins, this diet focusses on controlling insulin levels through a low refined carbohydrate diet. It explains refined carbohydrates being a major trigger factor for causing insulin rise and fall and stimulating the body to store energy as fat. It encourages the intake of foods with low glycemic index and works best to lose weight.
- Zone diet- This diet was devised by Dr Harry Sears, an American biochemist and recommends a nutritional balance of 40 % carbs, 30% fats and 30% proteins. It also encourages the use of high-quality unrefined carbohydrates such as olive oil, avocado, nuts, etc. The diet claims to reduce inflammation in the body, slow ageing and decrease the risk of chronic diseases.
- Ketogenic diet- This diet is a very famous and well-known diet even practised for medicinal purposes, eg. in the treatment of epilepsy. It focusses on reducing carbohydrate intake and increasing fat intake so that the body avoids breakdown of carbs and enhances breakdown of fats to ultimately cause ketosis to provide energy. The advantage here is that one eats fewer Cals and still doesn’t get hungry. It encourages food to contain 75% Cals from fat, 20 % from proteins and 5% from carbs. However, it should be practiced with caution in diabetics.
- South beach diet- This was started by Dr Agatson and Marie Almon and suggested that a control of insulin decreased risk of heart diseases in individuals. He explained that low-fat diets were not effective in the long-term and how slow unrefined carbs were beneficial for health. This diet became popular as it also led to weight loss of about 3.6 to 5.9 kgs in the first two week period of phase 1 and 0.5 to 1 kg per week in phase 2.
- Mediterranean diet- This diet focused on eating plant foods such as fresh fruits and vegetables along with lean meat. It also talked of increasing legumes, olive oil and whole grains in one’s diet. It suggested that one-third of one’s meal should contain fats and saturated fats in it should not exceed 8%. This diet has proven to be maximally effective to reduce heart diseases. It lowers the LDL cholesterol and is more effective in individuals with type 2 DM. Treatment has also been credited to having a lower likelihood of cancers such as the breast ca, as well as other conditions such as Parkinson’s disease and Alzheimer’s disease.
- Raw food diet- Here, it was suggested that 3/4th of a person’s diet should contain raw uncooked food items that are unprocessed and preferably organic. The diet is lower in sodium and helps in heart and kidney diseases. Some people claim that this diet can also clear up headaches, allergies, boost immunity and also improve arthritis and diabetes.
- Ramadan Diet- Ramadan is a festival celebrated amongst the Muslims on the 9th month of the Muslim calendar. They restrict eating and drinking from dawn to dusk and break their fast after sunset called iftar usually with dates being the first food item, to begin with. They also have a pre-fast meal early in the morning before sunrise called suhur. They believe that fasting during this time purifies their soul, and washes away their sins.
How to break fast :
However a majority of people break their fasts with a heavy intake of tasty food rich in carbohydrates and fats, that can sometimes negate the effects of the fast as it causes a sudden rise of blood glucose levels and dyselectrolytemias. There may be sudden death due to muscle mass loss and development of heart arrhythmias, by dyselectrolytemia and increased free fatty acids. Hence, one should break, fast with, a lot of clear fluids, liquids with high minerals, fruit juices; followed by eating a light meal, in lesser quantity. And slowly thereafter eat normally. This is for giving space to stomach and body metabolism to adjust. Food should be of a low glycemic index, unrefined carbohydrates(not less than 100gm carbohydrates per day), low saturated fats(less than 10%of total energy). Don’t drink a moderate amount after 2 to 3 hours of eating. And eat at least 2 hours before falling asleep (If one goes off to sleep post meal, a majority of this energy is made to store as fat).
Dr. Yoshinori Onsumi from Japan studied the concept of autophagy which is the Body’s way of cleaning. If not done, damaged cells and structures accumulate and various infected cells can also not be neutralized. He identified the genes that regulated autophagy and linked its disturbance to a host of degenerative illnesses. He won the Nobel Prize for this concept in 2016. Studies have shown that cells live longer and mitochondria make more energy during the fasting state than eating normally. With the restriction in Calorie intake, NO levels are boosted that causes essential rejuvenation and detoxification of the body. It also activates the nrf2 (nuclear factor-2 like protein) pathway that regulates the making of anti-oxidant protein and protects the body from oxidant damage along with other various anti-inflammatory effects.
Fasting has proven benefits in metabolic syndrome too. Studies say that if one reduces their calorie intake by a meagre 20% for 2-6 years there is a significant improvement in their blood pressure, blood sugar levels, body weight and cholesterol levels. High fat and sugar diets cause elevated levels of insulin and leptin and reduce levels of adiponectin and ghrelin. Elevated leptin levels are typically reflective of a pro-inflammatory state, whereas adiponectin and ghrelin can suppress inflammation and increase insulin sensitivity. Hyperinsulinemia may lead to hyperlipoproteinaemia, atherosclerosis, breast/colon cancer. Fasting may also elicit changes in the gut microbiota that protect against Metabolic syndrome.
According to neuroscientist Mark Mattson, Intermittent fasting by limiting the caloric intake on atleast two days a week can help improve neural connection in the hippocampus, improving memory and boosting the mood. It also protects neurons against Alzheimer’s disease as well as other neurodegenerative diseases such as Huntington’s Chorea and Parkinson’s Disease. Also fasting increases the production of the protein Brain Derived Neurotrophic Factor (BDNF) that strengthens the neural connections, and has anti-depressive effects. Ketogenic diet (1920s) is being further studied for various other diseases such as Alzheimer disease/cognitive impairment by causing decreased beta amyloid deposition, Parkinson’s disease, Amyotrophic lateral sclerosis, Traumatic brain injury, Hypoxic/ischemic brain injury, Autism, Depression, headaches and even Narcolepsy all by enhancing the mitochondrial function. Fasting has an ability to retard the aging process as well. 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 in mammals, which together with insulin is associated with accelerated aging and cancer. Studies done in mice, with alternate day fasting caused a major reduction in the incidence of lymphomas. Although no human data are available on the effect of fasting in cancer prevention, their effect on reducing IGF-1, insulin and glucose levels, and increasing IGFBP1 (insulin like growth factor binding protein 1) and ketone body levels could generate a protective environment that reduces DNA damage and carcinogenesis, while at the same time creating hostile conditions for tumor and pre-cancerous cells. In the treatment of cancer, fasting has been shown to have more consistent and positive effects.
In humans, one of the best demonstrations of the beneficial effects of fasting is in the treatment of rheumatoid arthritis. It is seen that during the period of fasting both inflammation and pain are reduced in RA patients. However, after the normal diet is resumed, inflammation returns unless the fasting period is followed by a vegetarian diet.
Who should not fast :
Pregnant women.People with wasting diseases or malnutrition.Those with a history of cardiac arrhythmias.People with hepatic or renal insufficiency.
And anyone who fasts for extended periods should do so only under close medical supervision.
Therefore to conclude, Intermittent fasting for healthy individuals, today is the key to achieving a better tomorrow. Fast should be done with awareness, healthy dietary foods(avoiding refined carbohydrates, saturated fats, tamas foods; encouraging high minerals, high vitamins, natural foods), cessation of smoking/ alcohol, maintaining good hygienic environment, and last but not least positive thinking. This will not only make us stronger individuals mentally but also give tremendous strength physically warding off a number of diseases and rejuvenating us completely.
The article has been authored by Dr Srikant Sharma, Senior Consultant Physician, Moolchand Medicity and Dr Karisma Walia at Moolchand Medicity .