Intermittent Fasting vs. Prolonged Fasting: Differences, Pros and Cons (2023)

FAQs

Intermittent Fasting vs. Prolonged Fasting: Differences, Pros and Cons? ›

Both intermittent and prolonged fasting are effective weight loss methods, and while prolonged has the added benefit of autophagy, its intensive calorie restriction makes intermittent fasting an easier option for long term weight loss.

For some, fasting may cause problems. For example, studies have found that people who regularly fast more than 16 or 18 hours a day have a higher risk of gallstones. They're also more likely to need surgery to remove the gallbladder.

Potential Drawbacks of Intermittent Fasting

If you're not already used to skipping meals or not eating for an extended period of time, the hunger and fatigue that can occur when starting IF can be difficult to handle. Other side effects can include insomnia, irritability, headaches, and nausea.

Intermittent fasting is safe for many people, but it's not for everyone. Skipping meals may not be the best way to manage your weight if you're pregnant or breast-feeding. If you have kidney stones, gastroesophageal reflux, diabetes or other medical problems, talk with your doctor before starting intermittent fasting.

2.4.

In addition, prolonged fasting leads to an increase in the concentration of growth hormone glucagon and a decrease in the blood levels of thyrotropin and T3/T4 [19]. The release and turnover of serotonin will increase during a prolonged fasting period [20].

Skipping meals and severely limiting calories can be dangerous for people with certain conditions, such as diabetes. People who take medications for blood pressure or heart disease also may be more prone to electrolyte abnormalities from fasting.

Insulin sensitivity helps in fat loss and protects the body from diseases such as diabetes, high blood pressure, and heart diseases. During the 16-hour fast, your body undergoes a process known as autophagy, a process where the body destroys old or damaged cells in the body.

As it stands now, the current evidence supports intermittent fasting as a weight loss method for up to 12 months. Some people are also probably not right for intermittent fasting. It's not recommended for anyone who is pregnant, has diabetes or is under 18.

Your Fasting Window is Too Short

This means it won't burn stored fat, and there won't be significant weight loss. As one study concluded, a fasting window of 18-19 hours is more effective in terms of weight loss than those between 12-17 hours [11].

Is it OK to intermittent fast everyday? ›

Longer periods without food, such as 24-, 36-, 48- and 72-hour fasting periods, are not necessarily better for you, and may be dangerous. Going too long without eating might actually encourage your body to start storing more fat in response to starvation.

One word of caution, though: Fasting can lead to an electrolyte imbalance. This can make the heart unstable and prone to arrhythmias. “So whenever we prescribe certain diets, including a very low calorie diet and protein-sparing modified fast diet, these require medical supervision.

If you don't eat for 10–16 hours, your body will go to its fat stores for energy, and fatty acids called ketones will be released into the bloodstream. This has been shown to protect memory and learning functionality, says Mattson, as well as slow disease processes in the brain.

The 16/8 intermittent fasting plan is one of the most popular styles of fasting for weight loss. The plan restricts food consumption and calorie-containing beverages to a set window of 8 hours per day. It requires abstaining from food for the remaining 16 hours of the day.

Twelve-hour fasting is a form of intermittent fasting (IF) also known as 12:12 that many people try for weight loss and health benefits, including improved digestion, increased energy, and improved sleep.

There is no set time that water fasting should last for, but medical advice generally suggests anywhere from 24 hours to 3 days as the maximum time to go without food. Throughout history, people have undertaken fasts for spiritual or religious reasons.

Water fast (24–72 hours)

Most people drink two to three liters of water per day during a water fast. The water fast lasts for 24–72 hours. You should not water fast for longer than this without medical supervision because of health risks.

Keep your fast under 7 days

Although humans seem to tolerate much longer fasts, this doesn't mean you should do them. It's not clear that fasts longer than 5-7 days are better. For example, ketosis seems to peak 5 days into a 21-day fast!

Breaking your fast with foods that are especially high in fat, sugar, or even fiber can be difficult for your body to digest, leading to bloating and discomfort. Foods and drinks that can be even more shocking to your system after a fast include those like a greasy cheeseburger, slice of cake, or soda.

The truth about lemon water and intermittent fasting

Long story short - the answer to the question “Does lemon water break a fast?” is no, lemon water does not break a fast. Lemon water contains almost no calories and zero sugars, it doesn't raise insulin levels, which means it will not break your fast (1).

What are the things not to do when fasting? ›

The bottom line. You can drink moderate amounts of black coffee during fasting periods, as it contains very few calories and is unlikely to break your fast. In fact, coffee may enhance the benefits of intermittent fasting, which include reduced inflammation and improved brain function.

The practice of 16/8 intermittent fasting involves limiting your intake of foods and calorie-containing beverages to a set window of 8 hours per day. You abstain from food for the remaining 16 hours, though you're still allowed to drink water and other no-calorie beverages, like plain coffee or tea.

YOU'RE NOT EATING ENOUGH DURING YOUR WINDOW

You'll be so hungry, you may start eating and not stop. As well, the body stores food to protect itself. Your body will sense the need to stock up on reserves and may store those extra pounds as fat instead of lean muscle.

Yes, you can do intermittent fasting for longevity every day. Research suggests that daily intermittent-fasting practices and longer-duration periodic fasting are safe strategies to improve your healthspan and lifespan.

According to some researchers, fasting for 10–16 hours can cause the body to turn its fat stores into energy, which releases ketones into the bloodstream. This should encourage weight loss. This type of intermittent fasting plan may be a good option for beginners.

Research shows that people who try intermittent fasting typically lose about 3 to 8 percent of their body weight— which, for a 200-pound person, is about 6 to 16 pounds.

Additionally, it will take your body a while to get used to this new eating schedule. So don't expect results right away. You may need to wait between 2 and 4 weeks to see or feel any results.

Eat a normal diet five days a week and fast two days per week. Eat normally but only within an eight-hour window each day. For example, skip breakfast, but eat lunch around 11 a.m. and dinner by 7 p.m.

Is it better to intermittent fast everyday or every other day? ›

“Generally evidence appears to suggest that alternate day fasting is as beneficial as more traditional methods of weight loss, such as creating a daily calorie deficit. Interestingly, of all intermittent fasting regimes, such as time-restricted eating, alternate day fasting appears to have a slight advantage.”

Metabolic switching through intermittent fasting results in improved metabolism, increased health span, and increased longevity through multiple processes [16,30].

Intermittent fasting affects cholesterol levels due to the change in metabolism from glucose to ketones. When this occurs, the body begins using lipids rather than storing them. Lipids move out of the cells, travel in the bloodstream, and go into the liver to be made into ketones.

Researchers say intermittent fasting can reduce inflammation in the body. Inflammation is one way the body fights infection, but if there is too much inflammation that can lead to various diseases.

Cardiovascular disease: Intermittent fasting promotes weight loss and appears to improve blood pressure, cholesterol and other indicators of cardiovascular health, says Mattson.

A key sign of autophagy is reduced appetite. It's likely due to changed levels of hormones like glucagon and insulin. Specifically, levels of glucagon tend to increase during autophagy. Glucagon helps manage your blood sugar levels and has been shown to suppress appetite ( 6 , 10 , 11 ).

It's pretty simple. Basically, during your 16-hour "fasting" period, you limit yourself to black tea, coffee, or diet soda. Then, for the next eight hours, you can eat whatever you want (no calorie counting needed). That's it.

The 5 Stages of Intermittent Fasting with the LIFE Fasting Tracker app: 1) Ketosis and heavy ketosis, 2) Autophagy, 3) Growth hormone, 4) Insulin reduction, 5) Immune cell rejuvenation!

Many people find the 16/8 method to be the simplest, most sustainable and easiest to stick to. It's also the most popular. There are several different ways to do intermittent fasting.

How can I drop 20 pounds fast? ›

Nutrition experts say that switching back and forth between fasting and eating again can bring many health benefits, including weight loss, reducing belly fat. However, to lose belly fat and get the nutrients you need, you should eat healthy, limiting sugary desserts and processed foods.

Fat burning typically begins after approximately 12 hours of fasting and escalates between 16 and 24 hours of fasting.

The 4-4-12 method has a shorter fasting window—12 hours—but eliminates snacking between meals. The goal here is to fast for at least four hours between breakfast and lunch, four hours between lunch and dinner, and at least 12 hours between dinner and breakfast the next day.

She says, “Not a minute more than 14 hours of fasting is recommended for women, as it can delay periods and increase the risk for anxiety and depression.” For men, she recommends that they can fast up to 16 hours.

One of the most common ways to do this is by skipping breakfast and only eating from midday-8pm, so you are fasting for 16 hours per day (between 8pm and midday the next day). Other variations of the diet involve 6-hour eating periods or shorter.

The results from 1422 subjects showed for the first time that Buchinger periodic fasting lasting from 4 to 21 days is safe and well tolerated.

Fasting for a week may result in adverse health and metabolic changes such as dehydration, a loss of lean muscle mass, hyperuricemia, hyponatremia, protein-sparing, sodium, and potassium-sparing, decreased serum calcium and magnesium levels, and acidic urine.

When you fast for 36 hours or more, you enter into the realm of extended fasting. The benefits of this practice include weight loss, lower blood sugar, ketosis, and enhanced autophagy. To help your body adapt to using body fat for energy, start with shorter fasts and work your way up to longer fasts.

The 40 Days of Prayer is inspired by Matthew 4:1-11, where Jesus fasted for forty days and forty nights and cited Scripture to resist the temptations of Satan. The forty days serve as a time of fasting and prayer to draw closer to God and strengthen your prayer life.

Can I safely fast for 30 days? ›

Because of all the risks, health professionals don't recommend fasting for a period longer than 1-3 days. Remember that it is dangerous to stick to this dietary pattern for a longer period without medical supervision.

To keep yourself safe, especially if you are new to fasting, consider limiting your fast periods to 24 hours or fewer and keeping a snack on hand in case you start to feel faint or ill. If you do become ill or are concerned about your health, make sure you stop fasting straight away.

No matter how many times I fast, day one is never easy and day two is always the most difficult (ghrelin, the hunger hormone, is said to peak on day 2 of a fast).

Although water fasting may have some health benefits, it comes with many risks and dangers. For example, water fasting could make you prone to muscle loss, dehydration, blood pressure changes, and a variety of other health conditions.

5:2 Intermittent Fasting

The research revealed that it takes four to six months to lose 20 pounds with no change in diet. Most intermittent fasting studies surrounding the 5:2 diet protocol or minimal calorie fasting days report significant weight loss.

The bottom line. You can drink moderate amounts of black coffee during fasting periods, as it contains very few calories and is unlikely to break your fast. In fact, coffee may enhance the benefits of intermittent fasting, which include reduced inflammation and improved brain function.

Fasts of 24-48 hours may be more beneficial for blood sugar control than shorter fasts, and they increase insulin sensitivity so that your body works more efficiently (1).

At that time Jesus was led by the Spirit into the desert to be tempted by the devil. He fasted for forty days and forty nights and afterwards was hungry. The tempter approached and said to him, “If you are the Son of God, command that these stones become loaves of bread.

The main drawback of 48-hour fasting is severe hunger, although many people claim that this feeling is temporary. In one study in 768 people fasting for at least 48 hours, 72% of participants experienced side effects, including hunger, fatigue, insomnia, and dizziness.

According to the Orthodox Church tradition, physical fasting, i.e. refraining from certain kinds of food for a certain period of time, is a necessary tool in the believer's effort to limit sin – as far as possible and with the grace of God.