What Is Intermittent Fasting And Does It Really Work
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Generally, intermittent fasting is a diet strategy that involves alternating periods of eating and extended fasting. Theres quite a bit of debate in our research community: How much of the benefits of intermittent fasting are just due to the fact that it helps people eat less? Could you get the same benefits by just cutting your calories by the same amount? said Courtney M. Peterson, Ph.D., an assistant professor in the Department of Nutrition Sciences at the University of Alabama at Birmingham who studies time-restricted feeding, a form of intermittent fasting.
We asked Dr. Peterson and a few other experts to help us sort out the real from the scam on intermittent fasting.
Can I Exercise During Fasting
However, for long-duration aerobic exercise, eating before exercise may increase performance.39 Its also important to drink fluids and replenish sodium around exercise when fasting. This is good to know if youre competing. Learn more
Try Sticking To The Following Foods On The 1: 8 Diet:
- Whole grains: Ones like rice, oats, barley, wholegrain pasta and quinoa will keep you fuller for longer.
- Protein: Meat, poultry, fish, eggs, nuts and seeds will keep you full.
- Fruit: Apples, bananas, berries, oranges and pears will offer good vitamin sustenance.
- Vegetables: Broccoli and leafy greens are especially good for making sure youre eating enough fibre.
- Healthy fats: Olive oil, coconut oil, avocados.
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How Much Weight Can You Lose With Intermittent Fasting
The amount of weight you can lose through intermittent fasting depends on your starting weight, medical conditions, type of food you eat on your non-fasting days, and other factors like your lifestyle, age, and activity level.
For example, if you choose to eat sugary desserts, drinks, and refined, ultra-processed carbs during your non-fasting days, a fast may not help you lose body fat.
However, if you pair intermittent fasting with healthy eating, you can experience healthy weight loss. A systematic review of 40 studies published in Molecular and Cellular Endocrinology found intermittent fasting was effective for weight loss, with a typical loss of seven to eleven pounds over ten weeks. If you weigh roughly 200 pounds, that equals a five percent loss of your total body weight in just ten weeks.
You might want a quick weight loss fix, but experts recommend you dont try to speed up the process. The Centers for Disease Control and Prevention and the UKs National Health Service recommend you shoot for a safe rate of one to two pounds per week.
According to the CDC, if you lose weight gradually and safely, youll be more successful at keeping it off. So, the average weight loss per week with intermittent fasting is safe, effective, and long-term.
Dark Chocolate And Cocoa Powder
Dark chocolate and cocoa are delicious sources of antioxidants.
In fact, cocoa provides at least as much antioxidant activity as any other fruit, including blueberries and acai berries .
Dark chocolate contains flavanols, which may help reduce the risk of heart disease by lowering blood pressure and keeping arteries healthy (
Reduce Stress And Improve Mental Health
The 16:8 diet help reduce cortisol levels and help reduce inflammation. Plus, since you wont be dealing with hunger for two days a week, its better for your mental health.
Those whove tried the 16:8 diet say how much more productive they are during fasting hours, spending less time stressing over food and more time channelling their energy into other beneficial tasks throughout the day.
How Long Should I Intermittent Fast To Lose Weight
To lose weight, it is recommended to intermittent fasting, men can fast for 16 hours and eat for 8 hours while women are recommended to fast for 14 hours and eat what they want for the remaining 10 hours.
You are not expected to eat any food during the fasting but can drink as many no-calorie drinks as you want and it can be done once or twice per week or every day.
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How To Do Intermittent Fasting
If you are just getting started with intermittent fasting, we recommend slowly working up to your target fasting schedule over the course of several weeks or months. Start by reflecting on your eating habits. Do you snack in between meals or after dinner? If so, try a 12-hour fast overnight. This means you finish dinner by 7 pm, for example, and dont eat anything else until 7 am the next day. If you usually dont feel the need to eat after dinner or between meals, try a 14-16 hour fast . If youd like to fast longer, add 1-hour increments every 5 days or so. Drink water to keep you both hydrated and distracted from hunger. If you need caffeine, drink unsweetened black coffee and tea.
31 daily challenges to get started with intermittent fasting
What To Eat During Intermittent Fasting 16/8
Though intermittent fasting isnt a diet in the sense that there are food-specific restrictions imposed, it is recommended that you eat as many whole foods as possible and avoid processed foods. The quality and nutritional value of food matters greatly when practicing any kind of health plan, advises Wandzilak.
According to Grant, what you choose to eat will depend on your goals. When doing any type of fast, water is the most common beverage to consume during your fasting period. However, if youre looking for a lifestyle rebootor if your goal is weight losscoffee or tea is acceptable during fasting periods as well.
If gut rest is your ultimate goal with fasting, then no food or beverages, aside from water, should be consumed during a fast, explains Grant. However, if longevity, weight loss or metabolic benefits are your goal, then sometimes a few calories, such as plain coffee or tea, can be consumed during your fasting period without having much of a negative impact on the outcomes.
Most experts agree that standard diet recommendations are also encouraged when intermittent fasting, though Grant specifies that prioritizing protein during your first meal of the day can help your body as it rebuilds and repairs as it prepares to once again enter the digestion phase.
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How Often Should You Do 1: 8 Intermittent Fasting
Unlike other intermittent fasting diets, each day of the 16:8 works independently to the other days. This means that you can do anywhere from one day of intermittent 16:8 fasting to seven days a week, depending on your goals and the advice from your GP.
Evidence differs, however, on whether its healthy to do intermittent fasting all the time for a number of reasons. While one study suggests that fasting helps your vital organs by giving metabolic functions a break, other research suggests the fasting can lead to an increased level of cholesterol and can lead to feelings of nausea, along with causing spells of low-blood sugar and dehydration.
Overeating And Potential Weight Gain
Restricting your intake to just 8 hours per day may cause some people to eat more than usual during eating periods in an attempt to make up for hours spent fasting. This may lead to weight gain, digestive problems, and unhealthy eating habits.
Interestingly, current research doesnt suggest that intermittent fasting leads to any more weight loss than typical diets that recommend overall calorie restriction. Both eating patterns may lead to modest weight loss .
If weight loss is your primary goal, you may therefore prefer to lower your calorie intake instead of fasting intermittently to prevent the overeating that may occur when restricting intake to a certain time window.
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Intermittent Fasting 16/8 Risks
As with any diet plan, you should begin by consulting your doctor. Grant specifies that everyones body responds differently to intermittent fastingdue to genetics, current health, pre-existing conditions, and lifestyleand isnt recommended if you have Type 1 diabetes, are pregnant or have a history of disordered eating. Speaking to your doctor and consulting a nutritionist or dietitian is beneficial if you are unsure of how to approach intermittent fasting or are looking for guidance personalized to your lab work and specific goals.
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It is important to know that researchers admit further research is needed in specific areas of intermittent fasting. For example, most research has been performed on overweight and middle-aged adults. Additionally, some research disputes that intermittent fasting is an effective eating method for those whose goal is losing weight. This study, however, was conducted in overweight and obese adults, further proving the need for studies to be conducted on people whose weight falls in the healthy range. With this in mind, its important to work with your doctor is the key to understanding if intermittent fasting will work for you and your specific goals.
It May Be Difficult For Some People To Stick To
One of the most obvious limitations of the Warrior Diet is that it restricts the time during which you may eat substantial meals to a four-hour period.
This can be difficult to stick to, especially when participating in normal social activities like going out to breakfast or lunch.
While some people may feel great when consuming very small amounts of calories over a 20-hour period, others may find that this way of eating is not ideal for their lifestyle.
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A Weekly 24 Hour Fast
Also known as the Eat-Stop-Eat diet, this intermitent fasting pattern involves eating no food for 24 hours at a time. Many people fast from breakfast to breakfast or lunch to lunch.
People on this diet plan can have water and other calorie-free drinks during the fasting period. On non-fasting days, one can eat in a regular pattern. Eating in this manner reduces a persons total calorie intake, but does not limit the specific foods that the individual consumes, explains Bahl.
A 24-hour fast can be quite challenging as it may lead to fatigue, headaches, or irritability. Over a period of time, people may get used to this new eating pattern, and start seeing the benefits.
Losing Weight Vs Losing Fat: Whats The Difference
When you watch the numbers on your scale drop, it can be exciting. But the scale doesnt reflect if youve lost fat or weight in general. You may think the goal of your health journey is to lose weight, when what you really want is to shed body fat. The reason is simple: When you lose weight, you can lose a combination of muscle, fluids, fat, and even organ size.
If you want to increase your health and add muscle so your body feels and looks toned, losing muscle and fluids likely isnt your goal. Instead, youll want to focus on fat loss, so any more than two pounds a week could undermine your goals.
According to research and Doctor Joel Seedman , when you shed upwards of five pounds per week, youll lose water weight and muscle along with your fat. Muscle and water loss can be dangerous, since it puts you at risk for dehydration, nutrient deficiencies, poorer fitness and mental performance, and puts you at risk for regaining the weight. To combat this, incorporate strength training into your workout routine. Cardio can promote fat burning, but you need resistance training to maintain your muscle mass. Also, the more muscle mass you have, the higher your metabolic rate. Basic strength training exercises, such as squats, lunges, and push-ups, can add muscle and improve your body fat composition.
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It May Aid Weight Loss
Various methods of intermittent fasting, including 20-hour fasting cycles, have been linked to weight loss.
One study, which closely mimicked the Warrior Diet , found that people who consumed meals over four hours in the evening experienced more weight loss than those who consumed the same amount of calories in meals throughout the day.
Whats more, those who ate one meal per day showed significantly reduced fat mass and greater muscle mass .
A recent review of six studies concluded that various types of intermittent fasting, ranging from 3 to 12 months, were more effective at promoting weight loss than no dietary intervention.
However, the review found that there were no significant weight loss differences between dieters using intermittent fasting or continuous calorie restriction , meaning that calorie restriction without fasting was equally effective .
Additionally, although reducing calorie intake is the most common outcome of the Warrior Diet, some people following this eating pattern could technically consume too many calories during the four-hour overeating period and experience weight gain.
What Is Intermittent Fasting And How Is It Done
Even if youve never tried IF, youve likely fasted before, without even thinking about it. Fasting is often required for blood tests, medical procedures, or surgery, for example.
When you are fasting, you naturally get fewer overall calories, says Vandana Sheth, CDCES, a dietitian and nutritionist who specializes in diabetes management in her own practice in Torrance, California. The fasting state also causes an increase in growth hormone levels, increase in norepinephrine, and decrease in insulin levels, and these changes in the hormones also cause an increase in our metabolic rate. All of these factors of intermittent fasting help with weight loss.
There are different ways to do IF, including skipping meals and eating only during a certain time period, or restricting calories on certain days of the week and eating normally on other days, according to the Association of Diabetes Care & Education Specialists. The most common IF diets consist of a 16-hour daily fast, a 24-hour fast on alternate days, or a two-day-a-week fast on nonconsecutive days, according to the authors of the Nutrients analysis.
Whatever plan you choose after consulting your care team, including a dietitian who specializes in diabetes should be tailored to your lifestyle, type 2 diabetes symptoms, and nutritional needs.
Your Fasting Window Is Too Short
If you want to notice a difference in your body weight, your eating window during your intermittent fasting diet should be significantly less than normal.
If the difference between your eating window before and during intermittent fasting is only an hour or two, you might barely notice significant weight loss.
A 14-hour fasting window with a 10-hour eating window seems like a great place to start. However, if you find the 14 hours to be too long, you could start with a shorter fasting duration and work your way up.
When Can I Resume Intermittent Fasting
Intermittent fasting can be done while breastfeeding, but it needs to be done very carefully. If you find that you can’t get enough calories, nutrients, or fluids while intermittent fasting, you may choose to hold off until it’s safer for you to try.
It’s not just about whether or not you’re still nursing, either. You want to be getting solid sleep overnight so that intermittent fasting doesn’t take an extra toll on your stress hormones. “I would recommend resuming intermittent fasting your baby is completely weaned and has a relatively regular sleep schedule,” notes Dr. Reisdorph.
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Isnt Fasting The Same As Reducing Calories
No, not necessarily. Fasting can reduce the time you spend eating and primarily addresses the question of when to eat.62 Calorie reduction addresses the question of what and how much to eat. They are separate issues and should not be confused with each other.
Foods To Eat On A Ketogenic Diet
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The ketogenic diet has become popular.
Studies have found that this very low carb, high fat diet is effective for weight loss, diabetes, and epilepsy .
Still, higher quality research on the diet is still needed to determine its long-term safety and efficacy .
A ketogenic diet typically limits carbs to 20 to 50 grams per day. While this may seem challenging, many nutritious foods can easily fit into this way of eating.
Here are some healthy foods to eat on a ketogenic diet.
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There Is Interest In Whether Autophagy Can Increase The Lifespan Of Whole Organisms Though So Far This Has Only Been Replicated In Animals
There is interest in whether autophagy can increase the lifespan of whole organisms, too though so far this has only been replicated in animals, like 1mm-long nematode worms and mice, and not humans . Until there are longitudinal studies of human intermittent fasters, it is too soon to say that it will extend our lifespans.
But, other animal studies have linked autophagy to improvements in immune system memory. The fact that autophagy is essential to maintain cell health has also generated interest in its role in cancer suppression. There might be more reasons than increasing lifespan to take interest in autophagy.
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Unlike calorie-restrictive diets , the purpose of intermittent fasting is to increase the amount of time between the last meal of one day and the first of the next. This could help to promote autophagy, but to understand how we should look at what happens to us after we eat.
Eating even a small bite before bed extends the “fed state”, meaning you may never achieve ketosis before your next meal
When you stop eating at 19:00 you will still be in the fed state until 22:00 because you will still be digesting nutrients, says Clarkson. Any carbohydrates in your diet will give you a nice supply of glucose, our premium source of fuel, for a few hours.