Intermittent Fasting (IF) is a way to reduce calories as an alternative to traditional low-calorie diets. The emphasis is on the timing of eating, not only how much food you eat. There are many ways to implement IF from fasting a day or two a week to limiting hours of eating every day.
IF has been growing in popularity, as have the proposed health benefits of fasting. Before jumping on the IF bandwagon, read below to learn how to intermittent fast, what it is, and what the true health benefits are.
What Is Intermittent Fasting?
Intermittent fasting is not exactly a diet, but rather an eating pattern. Instead of focusing on not exactly what to eat, IF places emphasis on when to eat.
Fasting and feasting with intent mean consuming calories during a specific window of the day. The remainder of the day is essentially devoid of food, or the "fasting" portion.
The most basic form of fasting is a pattern the majority already does. Fasting between the last meal of the day (generally dinner) and breakfast the next morning (hence "break" the "fast"). More extensively in the health world, fasting periods tend to go for longer bouts of time.
Other common types of intermittent fasting include fasting for one or two non-consecutive days a week or limiting the hours of eating every day, also called time restrictive eating (TRE).
The general idea is to focus on having non-eating time to allow your body and digestive tract to adjust without having food. This way of eating is thought to increase metabolic flexibility - the ability to shift between using carbohydrates or fat as a fuel. IF can teach the body to tap into fat stores when glucose is not readily available during fasting periods.
Is Intermittent Fasting Safe?
Most IF methods are considered to be safe. However, it is always recommended to consult with a clinician before starting any diet or eating regimen. This is to ease any side effects and risks of IF, including fatigue, dizziness, shakiness, and brain fog.
Intermittent fasting may not be suitable for the following populations and those with specific health conditions such as:
• Women who are trying to conceive, pregnant, or breastfeeding
• Children and adolescents
• People with a history of or current eating disorder
• Those managing diabetes and low blood sugars
• People considered to be underweight
Prospective followers should likewise consider the potential downfalls of intermittent fasting. For instance, devoting time to not eating can be a social stressor with work dinners and family holidays. Exercising while in a fasted state can lead to plummeted energy and increased recovery time, too.
It is likewise important to note consuming a copious amount of calories is not recommended. Overeating will likely lead to weight gain and deter such benefits. A healthy lifestyle incorporates regular exercise, adequate sleep, and stress management.
Ultimately, implementing eating patterns and strategies should work best for personal lifestyles. And like any sort of diet or eating pattern, their success relies on if they can be sustained long-term.
8 Benefits of Intermittent Fasting for Weight Loss & Health
The following health benefits of IF are research-backed, but research is ongoing to further clarify the ways IF impacts health.
1. Supports Weight Loss
Like other eating shifts, research suggests you can use intermittent fasting for weight loss. However, most studies do not suggest IF is superior to other calorie restriction efforts for sustained weight loss, according to Harvard Health.
A 2018 study concluded IF led to similar weight loss as consistent calorie restriction in study participants after 50 weeks. IF may cause a higher weight loss compared to more traditional lower-calorie diets, but long-term effects for weight loss appear to be similar.
Like efforts to lose weight, the biggest weight loss with IF is seen more short term from one to six months after starting.
2. Benefits Heart Health
In tandem with weight loss, IF can offer heart health benefits. With weight loss, blood pressure goes down. Some, but not all, studies have also shown IF can positively affect blood cholesterol levels, according to a 2021 review.
3. Fights Cancer Cells
Consistent calorie restriction has been shown to lower the risk for certain cancers. However, the problem is consistent calorie restriction is not sustainable for most people. IF can be a more palatable alternative to consistent calorie restriction specifically for the benefit of lowering the risk for cancer growth.
According to a 2021 review on IF and cancer, the effects of IF on cancer in humans are still not well understood. It is thought IF may have a role in cancer prevention linked to the benefit of weight management. Weight loss with lowering fat mass can help fight inflammation.
Doing IF while taking chemotherapy may have some benefits for shrinking cancer cells, but more research is needed. Health experts do not suggest starting IF with chemotherapy unless directed by your healthcare team.
4. Helps to Manage Diabetes
According to a review on intermittent fasting and diabetes, IF could be a way to treat or potentially reverse type 2 diabetes. IF has been shown to be effective at reducing body weight, decreasing fasting blood sugar, decreasing fasting insulin, reducing insulin resistance, and decreasing levels of leptin.
The benefit IF has on diabetes could in large part be to the weight loss from IF. If you are on medications or insulin for diabetes, speak with your doctor before trying IF.
5. Promotes Longevity
According to the National Institute on Aging, animal studies have shown calorie restriction (10 to 40 percent fewer calories than usual) can lower the risk for chronic diseases and can help increase life span.
A main line of thinking for this health benefit is calorie restriction and IF helps lower inflammation in the body which can, in turn, lead to lowering the risk for most diseases. The lowered inflammation is also tied to weight regulation as mentioned above.
6. Benefits Brain Health
Besides weight regulation and heart health, IF can also provide brain health benefits. A 2017 study suggests animal and cell research has shown IF to protect brain cells from damage or plaque build-up associated with Alzheimer’s disease.
National Institute on Aging suggests IF can offer brain protection because fasting shifts brain fuel from glucose to ketones. Ketones come from fat and are sent to the brain when the body does not have any more stored glucose. This flexibility in fuel sourcing for the central nervous system may help lower the risk for cognitive decline.
7. Helps Control Cravings
Food cravings are often more of a mental desire than a physiological need like hunger. Fasting can help limit cravings by encouraging you to tune into hunger and satiety cues, along with reminding you of the reality we do need to rely on food as much as we think, especially in a Westernized diet.
8. Supports Gut Health
A 2021 study found IF for one month positively improved the gut microbiome by increasing the number of helpful bacteria, called probiotics, in the gut. Researchers note the health benefits of IF may mostly stem from the impact IF has on gut health.
8 Steps to Do for Intermittent Fasting
Interested to see what all the hype is about? If intrigued and ready to start fasting, here are some tips to ease starting an intermittent fasting journey no matter what type of fast you decide to do.
1. Consult with a Doctor
Especially if managing any medical condition or taking medication, consult with a clinician before starting intermittent fasting or any new diet.
Meeting with a Registered Dietitian can also help identify personal goals and create a sustainable plan to meet them.
2. Address Worries and Questions
"What if I get hungry?" and "Can I exercise in a fasted state?" Address these "what ifs" and questions personally and with a healthcare professional.
Doing so helps clear any confusion and smooth the process of following an intermittent fasting eating pattern.
3. Start Slow & Ease Into the Plan
"Easy does it" is the name of the game when it comes to intermittent fasting. For instance, rather than jumping in quickly and fasting for a 24-hour fast, start the process slow.
This may include gradually skipping breakfast, snacks, etc. Fast for longer bouts as the fasting periods become more comfortable.
4. Be Patient with the Process
Especially in the beginning, it is important to not judge the effects in the first day two. This is due to an increased likelihood of experiencing brain fog and low energy.
At least give the chosen fasting protocol a three-weeks shot chance before throwing in the towel. The longer this sort of lifestyle is practiced, the easier and more regimented it will become.
5. Use Time as an Advantage
Rather than fixating on hunger between fasts and feasts, make the most out of time by staying busy.
Also, be sure to sleep the recommended seven to nine hours on a nightly basis. Not only is this imperative for overall health, but it can help carve out more of the allotted fasted time.
6. Keep Hydrated
Drink plenty of water, as keeping hydrated helps make the fasting periods easier to get through. Black coffee, tea, and other sugar-free drinks are viable options to sip on during fasted states.
7. Focus on Quality Foods
While intermittent fasting does not necessarily harp on the foods to consume, nutrient-dense foods should be the focus no matter what eating pattern you adopt.
Nourishing the body with whole grains, fruits and veggies, lean proteins, and healthy fats supports weight loss and overall health.
8. Experiment with Various Strategies
Diets and eating patterns are not one-size-fits-all. And what works for one person, may not work for the next.
So experiment and try different strategies that work best for personal goals, needs, and schedules. Stay flexible and open to what you need for health - physically, mentally, and spiritually.
Intermittent Fasting In Conclusion
IF is an eating style focusing on WHEN you eat and incorporating periods of time when you do not eat. Having set times when food is not eaten can help lower calorie intake which could benefit weight loss. Following IF could also benefit heart health, diabetes management, gut health, longevity, and protect brain cells throughout aging.
While there are intermittent fasting health benefits that are research-backed, there is still much we do not yet understand about IF and how the different types of fasting impact some health outcomes.
The bottom line is IF can be a healthy approach to eating, but it may not be best for everyone. Consult your doctor to determine if it could be right for you before trying it.
References:
Albosta M, Bakke J. Intermittent fasting: is there a role in the treatment of diabetes? A review of the literature and guide for primary care physicians. Clin Diabetes Endocrinol. 7, 3 (2021). https://doi.org/10.1186/s40842-020-00116-1
Calorie restriction and fasting diets: What do we know? National Institute on Aging. Published August 14, 2018. https://www.nia.nih.gov/news/calorie-restriction-and-fasting-diets-what-do-we-know.
Clifton K, Ma C, Fontana L, Peterson LL. Intermittent fasting in the prevention and treatment of cancer. CA Cancer J Clin. 2021: 71: 527- 546. https://doi.org/10.3322/caac.21694
Not so fast: Pros and cons of the newest diet trend. Harvard Health. https://www.health.harvard.edu/heart-health/not-so-fast-pros-and-cons-of-the-newest-diet-trend.
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