What The Studies Show
Intermittent fasting has been shown, in many short-term research studies, that it can help you lose weight, improve your health and potentially protect you from developing certain diseases. And whats most appealing, is that it doesnt restrict you daily, like conversional dieting.
Studies have also shown that intermittent fasting may help prevent or even reverse diabetes. This is because it helps to control and reduce insulin and glucose concentrations in your blood.
However, theres still not enough studies to show how safe intermittent fasting is if you do it for a long time. But in general, most research highlights that its safe in otherwise healthy adults.
The Difference Between Short And Long Fasts
Every night when we stop eating and then go to bed, we go through a short-term fast until our first meal of the next day. Depending on when you ate dinner and when you consume your first meal after you wake up, you can easily go through a 12 to 16-hour fast with no physiologic change to digestive functions.
Although there is no clear consensus or accepted definition about what the cut off is between a short and a long-term fast, Diet Doctor defines anything less than 24 hours as time-restricted eating, fasts between 24 and 36 hours as a short-term fast, and anything longer than 36 hours a long-term fast.
Time-restricted eating and short-term fasts dont require specific precautions when breaking the fast. Just remember it is a good idea not to binge on highly-processed, sugary, or high-carb foods because you will undo the advantages of the fast. Plan to eat a wholesome, low-carb, high-fat meal, such as any of the meals featured in the Diet Doctor recipes, and you will be just fine.
Does Intermittent Fasting Have Different Effects On Men And Women
The quick answer is: yes, Intermittent Fasting can affect men and women differently.
Anecdotally, we have many women in our online coaching program that swear by Intermittent Fasting, while others have had adverse effects.
Lets dig into the science and studies.
A recent PubMed summary concluded thatfasting can be prescribed as a safe medical intervention as well as a lifestyle regimen which can improve womens health in many folds .
Now, in that extract, many of the studies cited are focused on specifically calorie restriction , and they also say that future studies should address this gap by designing medically supervised fasting techniques to extract better evidence.
Digging into the PubMed Archives brought me to the following conclusions :
One small study resulted in the following: Glucose response to a meal was slightly impaired in women after 3 weeks of treatment, but insulin response was unchanged. Men had no change in glucose response and a significant reduction in insulin response.
Another small study studied the effects on their menstrual cycles after a 72 hour fast which is significantly longer than any fast recommended in this article: in spite of profound metabolic changes, a 72-hour fast during the follicular phase does not affect the menstrual cycle of normal cycling women..
Precision Nutrition a great resource recommends not attempting Intermittent Fasting as a woman if:
- youre pregnant
- you dont sleep well
- youre new to diet and exercise
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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
How To Do Intermittent Fasting Safely
Fasting for weight loss can be effective, but you need to do it safely. Here’s what you should know first.
Fasting for weight loss can be effective, but you need to do it safely.
You’ve probably heard of intermittent fasting, the popular diet that involves restricting the hours during which you can eat. It’s heralded as a weight loss method, and research suggests that it can also boost your immune system, cure high blood pressure and more.
Intermittent fasting is well-known, but it’s only the tip of the iceberg when it comes to fasting diets in general. There’s practically infinite ways you can adopt a fasting regime that suits your own lifestyle and health needs. Let’s take a look at all the different fasting diets, the health benefits they may bring and how to do them safely.
Read Also: What Is The Range For Non Fasting Glucose
Dont Break Fasts With A Feast
It can be tempting after a period of restriction to celebrate by eating a huge meal.
However, breaking your fast with a feast could leave you feeling bloated and tired.
Additionally, if you want to lose weight, feasting may harm your long-term goals by slowing down or halting your weight loss.
Because your overall calorie quota impacts your weight, consuming excessive calories after a fast will reduce your calorie deficit.
The best way to break a fast is to continue eating normally and get back into your regular eating routine.
Summary If you eat an unusually large meal after your fast day, you may end up feeling tired and bloated. Try easing gently back into your normal food routine instead.
Intermittent Fasting Can Be Hard But Maybe It Doesnt Have To Be
Initial human studies that compared fasting every other day to eating less every day showed that both worked about equally for weight loss, though people struggled with the fasting days. So, its very reasonable to choose a reduced calorie plant-based, Mediterranean-style diet. But research suggests that not all IF approaches are the same, and some IF diets are indeed effective and sustainable, especially when combined with a nutritious plant-based diet.
We have evolved to be in sync with the day/night cycle, i.e., a circadian rhythm. Our metabolism has adapted to daytime food, nighttime sleep. Nighttime eating is well associated with a higher risk of obesity, as well as diabetes.
Based on this, researchers from the University of Alabama conducted a study with a small group of obese men with prediabetes. They compared a form of intermittent fasting called “early time-restricted feeding,” where all meals were fit into an early eight-hour period of the day , or spread out over 12 hours . Both groups maintained their weight but after five weeks, the eight-hours group had dramatically lower insulin levels and significantly improved insulin sensitivity, as well as significantly lower blood pressure. The best part? The eight-hours group also had significantly decreased appetite. They werent starving.
Just changing the timing of meals, by eating earlier in the day and extending the overnight fast, significantly benefited metabolism even in people who didnt lose a single pound.
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Intermittent Fasting For Disease States
Recent studies support the use of intermittent fasting as a means of lowering blood glucose in people with diabetes and leading to overall improved health outcomes.
In particular, one study published in the World Journal of Diabetes found that subjects with type 2 diabetes mellitus implementing short-term daily IF significantly reduced body weight, fasting glucose and improved post meal glucose variability.
IF has been shown to:
- Improve markers of stress resistance
- Lower inflammation and blood pressure
- Improve glucose circulation and lipid levels, leading to a lower risk for cardiovascular disease, neurological disorders and cancer.
Beyond its application for diabetes management and reducing the risk of other diseases, IF is also proven to be as effective as some approved drugs for reducing some types of seizures and seizure-related brain damage and for addressing symptoms of rheumatoid arthritis.
Additionally, research is beginning to emerge showing positive effects of alternate day fasting on reducing the toxic effects of chemotherapy and decreasing morbidity rates associated with cancer.
How To Do A Dry Fast
This article was co-authored by Alyssa Chang and by wikiHow staff writer, Hunter Rising. Alyssa Chang is a nutrition coach and trainer, based in the San Francisco Bay Area. She uses her extensive background in brain-based neuroscience to work with clients on improving their connections with their brain and body to heal, reach goals, and move pain-free. She holds a BS in Kinesiology and Exercise, Nutrition and Wellness from the California State University, East Bay and is certified in Precision Nutrition, Z-health Performance and is certified by the National Council for Strength and Fitness.There are 10 references cited in this article, which can be found at the bottom of the page.wikiHow marks an article as reader-approved once it receives enough positive feedback. In this case, 84% of readers who voted found the article helpful, earning it our reader-approved status. This article has been viewed 269,988 times.
Dry fasting eliminates all food and water from your diet to help cleanse your body. A dry fast that lasts 1 day causes you to eliminate the same amount of water weight and toxins in your body as a 3-day water fast.XResearch source However, it is potentially dangerous to cut food and water from your diet since it can cause exhaustion and dehydration. Consult with your doctor to make sure it’s safe for you before you start!
Recommended Reading: Does Intermittent Fasting Burn Fat
Why Shouldnt I Fast
Dont fast if youre under eighteen years old, pregnant, or nursing.
And check with your doctor first if youre taking any prescription or over-the-counter medications to treat pre-existing conditions.
Fasting may also be a bad idea if you have a hot date coming up, you have self-control issues, or have a big race, presentation, or building ahead of you. See our Why Fast? post for details.
Planning Your Water Fast
Recommended Reading: What Food To Eat When Doing Intermittent Fasting
Fasting Vs Keto: Similarities And Differences
Your body gets lazy at this healthy natural process when you keep it regularly supplied with carbs.
But when you fast, you force your body to burn stored fat because theres no readily available glucose from eating carbohydrates.
Fasting triggers several desirable bodily processes, including:
You get into ketosis faster through fasting than you would by slowly transitioning to a fat-adapted state.
A Beginners Guide To Fasting: Everything You Need To Know About Fasting
Fasting refers to the deliberate abstention from food and/or fluids for a period of time, for therapeutic purposes. Many people dont know that fasting has been used for thousands of years in various religious and spiritual practices throughout human history, and in a sense, fasting is part of everyday life. The term breakfast is the meal that breaks the fast, which is done daily.
The recent increase in scientific research around fasting has allowed us to understand just how fasting positively affects our physiology, cells, aging, disease and overall health. What has been incredible for me to watch in my own clinic and coaching is how many people, regardless of symptoms or condition, have benefited from this completely free and simple biohack!
In 2016 Dr. Ohsumi changed the fasting landscape dramatically when he won a Nobel prize for his work on autophagy. Autophagy means self-eating and is the bodys way of cleaning out damaged cells in order to regenerate newer, healthier cells. Autophagy is like the fast track to healing and slowing the aging process. What does autophagy have to do with fasting? Well, fasting triggers this magical autophagy process. Essentially, fasting helps accelerate healing and gets your body to naturally repair itself!
Choose The Right Fasting Method For Your Body And Goals
When youre deciding how to begin fasting, your unique psychology, metabolism, and physiology each play a role:
- If youre the type of person who prefers to jump in with both feet, you may find the challenge of extended or more difficult fasting patterns rewarding.
- If youre feeling a bit uncertain about fasting, or arent sure how your body will respond to fasting, ease in instead.
- People who struggle with hunger or get hangry should start with a minimal fasting approach .
- Anecdotally, men may have an easier time with prolonged fasts, while women may need to adjust their fasting strategy at different times of their cycles.
Before you choose a fasting strategy, be sure to think about the ways your mindset and your body may affect your fasting experience.
Most people should probably start with 16/8 or another less-challenging approach like non-daily fasting, but theres no one-size-fits-all recommendation for fasting.
Broadly speaking, heres how your goal choice may affect your intermittent fasting approach and duration:
How To Eat On Fasting Days
There is no rule for what or when to eat on fasting days.
Some people function best by beginning the day with a small breakfast, while others find it best to start eating as late as possible.
Generally, there are two meal patterns that people follow:
Since calorie intake is limited 500 calories for women and 600 calories for men it makes sense to use your calorie budget wisely.
Soups are a great option on fast days. Studies have shown that they may make you feel more full than the same ingredients in original form, or foods with the same calorie content (
There is no specific, correct way to eat on fasting days. You have to experiment and figure out what works best for you.
Also Check: What Is Intermittent Fasting Mean
Getting Started With Intermittent Fasting: Next Steps
Intermittent fasting can potentially have some very positive benefits for somebody trying to lose weight or gain lean body mass.
Men and women will tend to have different results, just like each individual person will have different results. The ONLY way to find out is through a conversation with your doctor and self-experimentation.
There are multiple ways to do an Intermittent Fasting Plan:
- Fast and feast regularly: Fast for a certain number of hours, then consume all calories within a certain number of hours.
- Eat normally, then fast 1-2x a week: Consume your normal meals every day, then pick one or two days a week where you fast for 24 hours. Eat your last meal Sunday night, and then dont eat again until dinner the following day.
- Fast occasionally: probably the easiest method for the person who wants to do the least amount of work. Simply skip a meal whenever its convenient. On the road? Skip breakfast. Busy day at work? Skip lunch. Eat poorly all day Saturday? Make your first meal of the day dinner on Sunday.
After that, get started! Take photos, step on the scale, and track your progress for the next month.
See how your body responds.
See how your physique changes. See how your workouts change.
And then decide if its something you want to keep doing!
4 years later, I have no plans on going back to eating breakfast. Sorry General Mills and Dr. Kellogg!
If youre worried about all of this stuff, or arent sure when to eat and stop eating, try out our new app!
How To Break A Fast:
The worst thing you could do is start eating massive amounts of junk food, or any other food, really. This would cause stress to the intestines and your body needs time to readjust to food. Instead, what we need to do is slowly ease into it and be mindful of how to break a fast.
- The best way to start off is with a glass of hot lemon water. The citric acid gets absorbed really quickly and promotes the production of good digestive enzymes in the gut it gets the juices flowing. Drinking apple cider vinegar will wake up the intestines and prepares them for the feasting thats to come.
- Then, before having your actual first meal, eat something very small and low-glycemic, such as a half an avocado, a few nuts or vegetables.
- Your first meal should be something small and low-glycemic. This will keep you in a semi-fasted state because of the non-existent rise in blood sugar. Carbohydrate refeeding after fasting causes an abrupt weight gain. A spike of insulin will help you shuttle nutrients into your cells but also has some negative side-effects.
- After your first meal, wait an hour or two and continue with the second and third one. Wherever your dietary protocol may lie, you would still want to keep your blood sugar levels stable. Dont start piling down tons of processed carbohydrates because that would only make your fasting counter-productive.