The best of all Medicines are Resting and Fasting - Benjamin Franklin

Fasting is a very popular phenomenon followed by people throughout the world, be it for religious or for health purposes.  Its positive effects on the physical and mental well being has been discussed and documented right from our ancestors who used to eat before sunset and after sunrise.  Fasting is the willing abstinence or reduction from some or all food, drink, or both, for a period of time.

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However in today’s modern world, fasting has lost all its shine and people seem to be eating more and more in the name of health!  Here we will be exploring what is fasting all about, its effect on health, reason for fasting, types, misconceptions, myths and benefits.

What happens when we eat

So basically, food rich in carbohydrates and proteins increase the secretion of Insulin in the blood.  Insulin then converts food to glucose and transports it to required cells or store it in liver as glycogen.

What happens when we fast

  • Blood sugar and Insulin levels begin to fall 6-24 hrs after beginning fasting
  • Liver starts to break down glycogen to release glucose
  • Liver manufactures new glucose from amino acids (gluconeogenesis) 24hrs to 2 days after beginning fasting
  • Low insulin levels stimulate breakdown of fat (lipolysis) for energy.  Triglycerides (stored fat) is broken down into glycerol and fatty acids.  Fatty acids are used by body for energy, while brain uses ketone bodies (produced by fatty acids).
  • During fasting phase, body gets into the mode of using fat as energy instead of glucose.



Benefits of Fasting

Benefits of fasting


Ayurvedic concept behind fasting

According to the International Journal of Science, environment and technology, Ayurveda recognises the viewpoint that fasting realises the assimilation of metabolic toxins which are not good for health. It is also stated in Ayurveda that fasting encourages digestive fire with exclusion of blockage in the channel which helps in reducing of effects of any disease.

Types of Fasting

Fasting methods and protocols vary widely depending on the specific fast.

Diagnostic Fast

This fast may be a bit more difficult because it's not something most people elect to do. Your doctor may prescribe a fast before a medical procedure such as surgery or a blood test. It's important to stick to the recommended protocol for safety and accurate test readings.

Dry Fast

Arguably the most straightforward kind of fast, dry fasting involves not eating or drinking anything during the fasting period.

Liquid Fast or Water Fast

When liquid fasting, you only drink fluids and avoid eating solid foods. Liquid fasts can include broth, water, or concoctions made with water.  Water fasts only permit water during the fasting period. These fasts can last anywhere from a day to several days.

Juice Fast

Juice fasting, or juice cleansing, is a type of liquid fast lasting 3-5 days. It's usually conducted with detoxification or weight loss in mind. Juice fasts include organic, cleansing fruit and vegetable juices.

Partial Fast

There are two kinds of partial fasting. The first type is similar to liquid fasting except you may eat small amounts of solid food for the duration of the fast. The second type excludes certain foods for an extended period. Many people give up carbohydrates, alcohol, or red meat during this fast.

Intermittent Fast

Intermittent fasting is alternating periods of fasting and eating during the same day. This pattern may persist every other day, a few days at a time, or you may choose to adopt this style of fasting into your everyday life for an extended period. The food you eat while intermittently fasting may not change at all, or people may feast during the eating window. Some people simply eat all their meals within a small window of time in the afternoon or evening.

Alternate-day Fast

Alternate-day fasting is a much more intense fasting regimen than other fasting methods. This fast seems to be especially helpful for losing weight and maintaining weight loss progress. To qualify as an alternate-day fast, you must fast for at least 24 hours. Some people choose to extend alternate-day fasts up to 36 hours. Make sure to drink plenty of water during an alternate-day fast.

Extended Fasting

Extended fasts are usually 48 hours without eating, but they can last up to a week or longer. People may conduct this fast a few times a year or every month. These fasts are usually only conducted by people who have a high body mass index or who have trained their metabolism to adjust to long periods of fasting. Depending on the length of the fast, it may be necessary to add nutritional supplements to your water to keep your vitamins and minerals in balance.

Ketogenic Fast

Ketogenic fasts push your body into the fat burning state known as ketosis. A ketogenic fast is similar to a partial fast in that it includes a small amount of food. The two differ in the types of food consumed. On a ketogenic fast, you only consume fatty foods to shift your body into ketosis.

SInce IF is the most commonly followed type of fasting, let us look in detail about it.

Intermittent Fasting

Simple definition - Periods of fasting between periods of eating.  There are different fasting regimen and a person chooses the one that suits him the best.

IF can range from 12 hours to 3 months or more.  You can fast once a week or once a month or once a year.  Shorter fasts  are generally done more frequently while prolonged fasting  may range from one week to one month.

Types of IF

12-hour fast

  • Eating three meals a day from 7am to 7pm, then fast from 7pm to 7am
  • Include a light breakfast, a lunch and dinner containing low carbohydrates, moderate protein and fat, avoiding refined and processed foods
  • Results in low insulin levels in the blood which prevents insulin resistance and is effective in preventing obesity
  • However it is not powerful enough to reverse weight gain

16-hour fast

  • Fasting from 7pm to 11am daily with an 8 hour eating window.
  • Can include 2-3 meals in that 8 hour window
  • It is more powerful than 12 hour fast, coupled with a low carbohydrate diet can help in weight loss.  However losing weight is generally slow and steady

20-hour fast

  • In this fast, meals are eaten only in the evening with a 4 hour eating window


Fasting Tips

  • Drink water - Start each morning with 200-250ml of water to keep you hydrated
  • Stay busy - Fasting on a busy day helps to keep your mind off food.
  • Drink coffee/tea - act like appetite suppressant.
  • Ride the waves - Hunger comes in waves, it is not constant.  When it hits, slowly drink a glass of water or a cup of green tea.  The hunger pangs will slowly pass.
  • Give yourself one month - It takes time for the body to get used to fasting.  It is difficult initially, but eventually it gets easier.
  • Follow a nutritious diet - A diet low in sugar, refined carbohydrates, high in healthy fat and moderate proteins help the body stay in fat-burning mode and make fasting easier.
  • Dont binge - Don't eat anything and everything you lay your eyes on after breaking a fast, this will negate the benefits of fasting.
  • Fit fasting into your own life - Instead of changing your life to fit your fasting schedule, change the fasting schedule to fit your life. When there is an occasion like wedding/festivals/family get-together, do not try to fast.  Take a break and resume the regular fasting schedule.



Breaking the fast

Break your fast gently.  The longer the fasting period, the gentler you must be.  Overeating right after fasting often leads to stomach discomfort.  The following tips can be followed to break the fast:

  • Drink a glass of water before breaking the fast with a snack.
  • Start with small portions of fruits/salads and nuts like dates, walnuts and almond.  You can also start with broth/vegetable soup
  • Give a gap of 30 minutes post the small snack.  This gap will allow for any waves of hunger to pass and get your digestive system ready for the full meal.
  • Take the time to chew the food thoroughly to slowly get your digestive system started.
  • Don't rush through eating.  Take your time to relish each portion.


Common concerns during fasting

  • Hunger

It is a common concern during fasting.  Hunger usually comes in waves and generally passes after a period of time.  On continuing fasting for long period of time, appetite gradually decreases and hunger disappears.  Following drinks or spices can be consumed to suppress hunger/appetite.

  1. Water - Staying hydrated helps prevent hunger.  Drinking water before eating a meal may also reduce hunger and help prevent overeating.
  2. Green tea - Full of antioxidants and polyphenols, green tea is a great aid for dieters.  The powerful antioxidants may help stimulate metabolism and weight loss.
  3. Cinnamon - Cinnamon has been shown to slow gastric emptying and may help suppress hunger.  It may also help to lower blood sugar and therefore is useful in weight loss.  Cinnamon may be added to all teas and coffees for a delicious change of pace.
  4. Coffee - Helps to suppress hunger.
  5. Chia seeds - they are high in soluble fibre and omega 3-fatty acids.  These seeds absorb water and form a gel when soaked in liquid for 30min, which may aid in appetite suppression.  They can be eaten dry or made into gel or pudding..
  • Dizziness

Dizziness during fasting indicates dehydration.  Preventing this requires both salt and water.  Include plenty of fluids during fasting.  If need be, add sea salt to home made bone broth or mineral water.  Another possibility is low blood pressure, if a person is on medication for the same.  Dosage can be altered by discussing with the physician.

  • Headaches

Headaches are common first few days mainly because of the transition from high salt diet to a very low salt intake on fasting days.  Headaches are temporary and goes away with time.

  • Constipation

It is a common concern during fasting due to reduction in the food intake.  However by increasing the intake of fibre, fruits, vegetables during non fasting period help to deal with this concern.

  • Heartburn

To prevent heartburn after a fast, avoid taking large meals.  Avoid lying down immediately after eating.  In addition, drinking sparkling water with lemon often helps.

  • Muscle cramps

Low magnesium which is common in diabetics, may cause muscle cramps.  Can include magnesium supplements for the same.


Who should not fast

  • Severely malnourished or Underweight people

When body fat falls below 4%, the body is forced to use proteins in order to feed itself leading to muscle loss.  This syndrome is called wasting and is neither healthy nor beneficial in any way.

  • Children under 18 years of age

In children, proper growth outweighs all other health concerns, and adequate nutrition is an absolute prerequisite for normal growth.  Underfeeding may result in stunted growth, which may be irreversible.  Restricting calories also restricts the essential nutrients necessary for proper growth and development of vital organs, especially brain.

  • Pregnancy

The developing fetus requires adequate nutrients for optimal growth, and nutrient deficiency may cause irreversible harm during this critical period.  

  • Lactation

Developing babies receive all their nutrients from the mother in the form of breast milk.  If mother becomes deficient in nutrients then the baby will also be deficient leading to irreversible growth retardation.  For this reason, long term fasting is not advised.

  • Gout

Gout is an inflammatory arthritis caused by excess uric acid crystals in the joints.  Uric acid elimination through the urine decreases during fasting, resulting in a rise in uric acid levels.  This can worsen gout.  It is always better to consult the physician before starting on any kind of fasting.

  • Taking medications

Anybody who is taking medications e.g. aspirin, metformin, iron and magnesium supplements must consult the doctor before fasting.  Since certain medications are best taken with food, which obviously is not possible during fasting.

  • Diabetes

If you have type-1 or type-2 diabetes and are on medications/insulin then it is better to consult the physician to alter the dosage.  Fasting may cause the blood sugar to go extremely low leading to hypoglycemia (symptoms - shaking, sweating, irritability, fait, hunger and nausea).  Untreated hypoglycemia can be fatal.  

  • Gastroesophageal Reflux Disease (GERD)

In this condition, the stomach acid backs up into the esophagus, causing damage to the sensitive tissues of the esophagus.  Also called as heartburn.  This condition can worsen during fasting since there is nothing in the stomach to absorb the stomach acid.


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