All About Intermittent Fasting
What is intermittent fasting?
A scheduled series of voluntary fasting and eating intervals is often termed as intermittent fasting. It is an ancient tradition that people of various cultures and religions have been practicing over the centuries. People can either adopt alternate-day fasting, periodic fasting, or daily time-restricted eating while keeping their calorie consumption between 1200-1400 calories per day.
Intermittent fasting is not a diet, but instead a pattern of eating or fasting. A method for planning your meals with the goal that you benefit from them. Discontinuous/intermittent fasting doesn’t change what you eat, it changes when you eat.
The origin and a brief history of intermittent fasting
In the primitive time when our ancestors were lacking sufficient food, they discovered the fact that they can easily survive for a while upon their stored fat. It further assured them when they observed the bears who store all the fats for winter and then have a sound sleep in spring. This observation leads them to decide that they can fast for an interval and then can feast when they can manage. Intermittent fasting was a part of the lives of ancient hunter-gatherers who were unaware of the food availability that whether they would get something to eat or not.
Soon enough people realized and got sufficient evidence to prove the fact that intermittent fasting can be easily managed and has been involved in various metabolic benefits. A research conducted in 2014 proved that intermittent fasting results in rapid weight loss for about 3-8% within 3–24 weeks. It would not be wrong to say that intermittent fasting can help someone lose almost 0.55-1.65 lbs. per week.
Although the sustainability of intermittent fasting is unknown yet, The American Heart Association recommends that this sort of fasting can prevent people from cardiovascular disorders along with the improvement of insulin resistance. Contrastingly, the US National Institute on Aging says that there is not sufficient evidence for the recommendation of intermittent fasting. The institute encourages that one should seek advice from a health specialist before any alterations in the diet as it might be dangerous in certain health conditions.
Trends in Intermittent Fasting
Intermittent fasting is the hottest trendy diet that has gained the attention of researchers and clinicians. Since 2019, it became a common diet catching celebrity endorsement like Jennifer Aniston, along with high public interest. Similar fasting methods are also part of religious practice followed by Muslims, Hindus, Christians, and some other religious groups.
What are the types of intermittent fasting?
There are 3 different methods of intermittent fasting:
Alternate day fasting
Alternate day fasting is a method where a non-fasting day(normal eating-day) followed by a fasting day. Alternate day fasting is an extreme type of intermittent fasting, and it may not be reasonable for beginners or those with certain medical conditions. It may also be hard to keep up this type of fasting in the long term. There are 2 sub-types of alternate-day fasting:
- Complete alternate day fasting-No calories are consumed on a fast day.
- Modified alternate-day fasting-A person eats 25% of usual energy needs on a fast day
Periodic fasting includes any period of successive fasting more than 24 hours, for example 5:2 diet, it is a type of fasting plan where you normally eat 5 days and fast any 2 days a week. During the 2 fasting days, women generally consume 500 and men 600 calories instead of complete fasting.
Daily time-restricted feeding
Daily time-restricted feeding involves eating just for a specific number of hours every day. It is also called the 16:8 method or the Leangains diet-16 fasting hours cycled by 8 non-fasting hours. This timetable is thought to use the circadian rhythm.
Benefits and disadvantages of intermittent fasting
What are the health benefits of intermittent fasting?
Weight loss, fat loss: By reducing the window of time someone is allowed to eat generally results in less food consumption provided that this person eats a regular portion of food each time. The goal of IF diet for weight loss is to establish a fasting period that long enough to lower insulin levels and to trigger fat burning. Compared to the keto diet, this is another way to make the body use fat as energy instead of the one provided by carbs. When we combine intermittent fasting and strength workouts it helps the process of becoming lean and fit.
Disease prevention: Like every part of the body the gut needs to rest. This occurs when people are not overheating and let sufficient time between the meals. It is important for gut microbiota health along with the quality of what you eat. A healthy gut not only prevents digestive troubles but also helps to boost the immune system. People practicing intermittent fasting are less likely to develop heart diseases, type 2 diabetes, cancers, neurodegenerative diseases.
Extended longevity: Many studies have shown a correlation between how much we eat and live span. A study of Cell Metabolism conclude that:
Alternate Day Fasting Improves Physiological and Molecular Markers of Aging in Healthy, Non-obese HumansFrom Cell Metabolism
Unfortunately, just like breathing, eating is one of the necessary activities that contribute to aging. One of the ways of slowing down aging is to restrain the daily intake and to try intermittent fasting.
Side effects of intermittent fasting
Here are some drawbacks or cons of intermittent fasting:
- In the beginning stages of the plan: hunger, weakness, and tiredness.
- Periodic fasting prolonged for several days or weeks may cause malnutrition, eating disorders, increased susceptibility to infectious diseases, and moderate damage to organs.
What to eat for intermittent fasting
As we already mentioned before, intermittent fasting is not exactly telling what to eat but how often and when to eat. However, eating food that keeps a low insulin level and that contains all the required healthy nutrients will give the best results. Here are a few examples:
- protein (lean meat, fish, tofu)
- unrefined grains (whole oat, quinoa, brown rice, barley)
- non-starchy vegetables (asparagus, celery, spinach, beets)
- legumes (green beans, black beans, lentils)
- fruits (tomato, strawberry, grape, apple)
- unsweetened beverages (tea, water, green juice, smoothies)
- healthy fats (oil like grapeseed oil, seeds like chia seeds and almond)
- Spices (garlic, tumeric, cinnamon)
- Protein and fiber extend the feeling of fullness which makes fasting easier. Low carbohydrates containing in the legumes and unrefined grain do not create insulin spikes. This means less craving food and hardly any chance to experience hypoglycemia. To succeed with IF it is important to plan ahead both meal prep and fasting period.