Many people take up intermittent fasting but fail early on in their journey. A successful diet takes a lifetime commitment which is why it’s essential to know the pros and cons of intermittent fasting.
Imagine being able to eat anything you want most days of the week, reducing your intake for one or two days at a time, and still getting to lose weight. This is what many individuals feel when they first start practicing intermittent fasting and part of what entices intermittent fasting fanatics.
But before you get too excited and start implementing it, let’s take a look at how intermittent fasting can help you achieve your weight loss objectives while also enhancing your health. Consider this your beginner’s guide to intermittent fasting so that you can make a well-informed decision not only for your body but most especially, for your overall well-being.
What Is Intermittent Fasting?
Intermittent fasting (IF), also characterized as cyclic fasting, has gained favor in recent years as more research shows that it is generally safe and efficient. Intermittent fasting, on the other hand, is not a novel notion. It has been utilized for millennia during times of scarcity, and it even plays an important role in many major faiths1.
All diets work on the same principle: you consume less food energy each day than your body burns for normal activity. Intermittent fasting accomplishes this goal by severely restricting calories on specific days of the week or at specific times of the day. According to the theory, intermittent fasting can help reduce appetite by slowing the body’s metabolism2.
It is difficult to describe intermittent fasting because there is no single correct way to fast. In truth, there are numerous versions used around the world. Each has a unique eating pattern that is frequently closely followed in order to obtain physical or even spiritual results1.
How Does Intermittent Fasting Work?
According to significant study1 on the notion of intermittent fasting, it works in two ways to improve several aspects of health:
- Intermittent fasting reduces oxidative stress in cells throughout your body.
- Fasting boosts your body’s cellular ability to deal with stress. It stimulates your body’s stress response by activating cellular stress response pathways similar to relatively mild stimuli. As this happens on a regular basis, your body is gradually reinforced against cellular stress and becomes less prone to cellular aging and disease development.
Different Types Of Intermittent Fasting
Fasting on alternate days, for complete days with a certain frequency per week, or within a set time frame are the most prevalent techniques3. Here are exams of different types of fast:
- Alternate-day fasting – Alternating between days with no dietary restriction and days with one meal that supplies approximately 25% of your daily calorie demands. For example, fasting is observed on Mondays, Wednesdays, and Fridays, with no food restrictions on alternative days.
- Whole-day fasting – is defined as 1-2 days a week of complete fasting or up to 25% of daily your calorie needs, with no food restrictions on the other days. The 5:2 diet plan, for example, recommends no dietary restriction five days a week, followed by a 400-500 calorie diet for the remaining two days.
- Time-restricted feeding – entails following a meal schedule each day and fasting for a set amount of time. For instance, meals are served from 8 a.m. to 3 p.m., with fasting occurring during the remaining hours of the day.
Pros And Cons Of Intermittent Fasting
The diet trend requires going for a specified period of time without consuming any calories, but one essential thing you may notice about intermittent fasting is that there are a variety of ways to include this type of dietary trend.
The benefit of intermittent fasting is that the various methods allow you to select the option that is best for you. As with everything, there are advantages and disadvantages4.
1. Intermittent fasting encourages better body composition.
- Since you’re not consuming calories during fasting, it stands to reason that eating less than usual will result in weight loss. Fasting permits you to burn through all of your stored glucose as fuel before tapping into your fat reserves. You start losing body fat when we start burning fat storage. According to Healthline, intermittent fasting improves body composition by requiring a calorie deficit, increasing weight reduction and decreasing body fat, and generating good changes in your metabolism through hormone actions5.
2. Intermittent fasting helps in illness prevention and risk reduction.
- Intermittent fasting has the potential to improve some key risk factors for cardiovascular disease6. Fasting can help regulate diabetes, lower cholesterol, and lower blood pressure in addition to weight loss, all of which are essential aspects that should be addressed for disease prevention7. Researchers from the University of Surrey discovered that people who followed an intermittent fasting diet had a 9% lower blood pressure, compared to a 2% increase in those who maintained a more traditional, regular daily diet8. Intermittent fasting improves sleep time, which reduces blood sugar and inflammation, both of which are major contributors to chronic diseases including heart disease and diabetes9,10.
3. Intermittent fasting improves brain function.
- Fasting accelerates the creation and development of new brain cells and nerve tissues in the brain. As a result, cognitive performance, mood, focus, and memory improve11. Abstaining from food tests the brain and causes it to conduct disease-prevention strategies. This is due to the body entering ketosis, a state in which fat is used as a fuel source to increase energy and eliminate brain fog12.
4. Intermittent fasting can assist you in losing weight.
- Fasting promotes ketogenesis, which allows your body to use stored fat for fuel instead of glucose. Intermittent fasting raises human growth hormone (HGH) levels, which are connected to fat reduction and muscle building. In fact, in one alternate-day fasting research, participants shed an average of 8% of their body fat in just eight weeks13.
5. Intermittent fasting helps to reduce insulin resistance.
- According to research, intermittent fasting can reduce insulin levels and potentially enhance insulin sensitivity in prediabetics14. Fasting was found to increase weight reduction and gradually lower blood sugar levels in one study that employed type 2 diabetes patients as subjects15.
6. Intermittent fasting can also reduce inflammation.
- Diabetes, obesity, heart disease, Alzheimer’s disease, autoimmune disease, and cancer are all caused by chronic inflammation16. Fasting, on the other hand, has been shown in studies to reduce levels of systemic inflammation and pro-inflammatory cytokines. It also decreases oxidative stress, assisting your body in combating dangerous free radicals17.
7. Long-term commitment can be difficult.
- Intermittent fasting requires you to fast for a set amount of time, then eat a set amount of calories during a set window of time, then repeat in order to establish a caloric deficit. This protracted period of zero calorie consumption might be difficult to maintain long-term due to poor energy, desires, habits, and the discipline required to adhere to the specified time frames surrounding your bouts of intermittent fasting18. Intermittent fasting is particularly difficult to maintain long-term due to the quantity of self-control necessary. Both sides of intermittent fasting can be difficult; not eating while you’re meant to be fasting and not bingeing when it’s time to eat are equally vital.
8. Intermittent fasting can greatly increase the risk of adverse health effects.
- Those who already have an active lifestyle or are thinner before starting intermittent fasting may have hormone abnormalities. This could cause irregular menstrual cycles and reproductive concerns in women19. Hormonal imbalances can cause insomnia, increased stress, or thyroid difficulties in anyone20. Intermittent fasting is typically safe for most people if done under the supervision or approval of a physician and with thorough monitoring of body functioning.
9. Intermittent fasting can still make you gain weight.
- Intermittent fasting typically reduces your overall caloric consumption. This is a critical factor in the weight loss success of intermittent fasting. Many people become tired of yo-yo dieting and resort to fasting to lose weight without having to monitor calories. You can still gain weight if you overindulge during your eating window. When not fasting, intermittent fasting does not give you permission to binge on fast food and other garbage. Choose nutrient-dense foods like organic fruits and vegetables, grass-fed meat, wild fish, and healthy fats for fuel to achieve the best outcomes21.
10. Intermittent fasting can pose other side effects.
- Intermittent fasting may have unintended consequences for certain people. This is especially true when you first begin intermittent fasting. As your body acclimates to caloric restriction, you may feel a ‘fasting headache.’ Fatigue, dizziness, digestive disorders (including nausea, diarrhea, constipation, and bloating), irritability, sleep disruptions, dehydration, and malnutrition are among possible adverse effects21.
11. Intermittent fasting can have an impact on eating disorders.
- You may develop harmful eating habits as a result of the restrictive nature of intermittent fasting. Intermittent fasting may result in bingeing when you are not in your fasting window. This is especially true for persons who have had an eating disorder in the past. If you suffer from disordered eating, fasting may cause more harm than benefit21.
Intermittent Fasting Precautions
Although intermittent fasting has numerous health benefits, it is not suitable for everyone. If you have any of the following conditions, consult your doctor before starting intermittent fasting21:
- Diabetes or difficulty managing blood glucose levels: Diabetes patients must eat on a regular basis in order to maintain adequate blood sugar balance. If you have diabetes, intermittent fasting could induce dangerously low blood sugar levels.
- Intermittent fasting has been shown in studies to help decrease blood pressure. As a result, it could be dangerous for persons who already have low blood pressure.
- If you take diabetic, blood pressure, or thyroid medicine, you should proceed with caution. Fasting will have an impact on your absorption. Furthermore, several drugs are designed to be taken regularly with meals. Taking them while fasting may affect absorption and raise the likelihood of undesirable side effects.
- If you are underweight, you will require a regular supply of calories to sustain your energy levels. To find out if you’re underweight, use a BMI calculator or better yet consult with your doctor.
- Eating disorder history: We’ve already touched on this, but it needs reiterating. If you have a history of disordered eating, please refrain from fasting. Intermittent fasting can lead to undesirable eating habits such as bingeing.
- Trying to conceive: Intermittent fasting may affect fertility and produce menstrual changes. So, if you’re attempting to conceive, avoid fasting.
- If you’re pregnant or breastfeeding, it might be difficult to receive the nutrition you and your baby require during limited eating periods. Growing (or nourishing) a human demands a lot of energy. Fasting can limit your nutrients, which can harm your baby’s development.
If you’re thinking about trying intermittent fasting, talk to your doctor first. If you have specific diseases, such as diabetes, you should avoid skipping meals and significantly restricting their calorie intake. Moreover, if you are someone who uses blood pressure or heart disease drugs, you may be especially susceptible to electrolyte imbalances caused by fasting.
Certain persons who eat only one or two meals each day or do not eat for long periods of time may be more compliant with this type of regimen. Furthermore, persons who eat or snack excessively at night may benefit from limiting their eating time, especially if the late eating causes unpleasant side effects such as gastroesophageal reflux disease (GERD) or disrupted sleep.
Finally, while intermittent fasting is effective in maintaining a healthy weight as well as in weight reduction, it’s alway best to proceed with caution. Due to its possible adverse effects, you should check with your doctor before attempting any kind of fast to make sure that you won’t be doing yourself any harm.
6 Last, C. (2018, April 13). Heart attack and strokes: Intermittent fasting SLASHES risk, new study finds. Express.co.uk. https://www.express.co.uk/life-style/health/945658/5-2-intermittent-fasting-heart-attack-stroke
9 Marinac, C. R., Nelson, S. H., Breen, C. I., Hartman, S. J., Natarajan, L., Pierce, J. P., Flatt, S. W., Sears, D. D., & Patterson, R. E. (2016). Prolonged Nightly Fasting and Breast Cancer Prognosis. JAMA oncology, 2(8), 1049–1055. https://doi.org/10.1001/jamaoncol.2016.0164
10 Fast 13 Hours To Reduce Disease Risk | RedRiver Health And Wellness Center. (2016, October 12). RedRiver Health and Wellness Center. https://www.redriverhealthandwellness.com/fast-13-hours-reduce-disease-risk/
11 Salcido, B. (2019, December 9). 6 Surprising Brain Power Benefits of Intermittent Fasting. Medium. https://medium.com/@drbradysalcido/6-surprising-brain-power-benefits-of-intermittent-fasting-49ad1bc39e04
13 Johnson, J. B., Summer, W., Cutler, R. G., Martin, B., Hyun, D. H., Dixit, V. D., Pearson, M., Nassar, M., Telljohann, R., Maudsley, S., Carlson, O., John, S., Laub, D. R., & Mattson, M. P. (2007). Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma. Free radical biology & medicine, 42(5), 665–674. https://doi.org/10.1016/j.freeradbiomed.2006.12.005
14 Heilbronn, L. K., Smith, S. R., Martin, C. K., Anton, S. D., & Ravussin, E. (2005). Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. The American journal of clinical nutrition, 81(1), 69–73. https://doi.org/10.1093/ajcn/81.1.69
15 Arnason, T. G., Bowen, M. W., & Mansell, K. D. (2017). Effects of intermittent fasting on health markers in those with type 2 diabetes: A pilot study. World journal of diabetes, 8(4), 154–164. https://doi.org/10.4239/wjd.v8.i4.154
16 Furman, D., Campisi, J., Verdin, E., Carrera-Bastos, P., Targ, S., Franceschi, C., Ferrucci, L., Gilroy, D. W., Fasano, A., Miller, G. W., Miller, A. H., Mantovani, A., Weyand, C. M., Barzilai, N., Goronzy, J. J., Rando, T. A., Effros, R. B., Lucia, A., Kleinstreuer, N., & Slavich, G. M. (2019). Chronic inflammation in the etiology of disease across the life span. Nature Medicine, 25(12), 1822–1832. https://doi.org/10.1038/s41591-019-0675-013 Business Insider. (2017, October 25). I tried intermittent fasting — and it was one of the hardest things I’ve done. Insider. https://www.insider.com/i-tried-intermittent-fasting-how-to-start-what-it-is-2017-10
18 Brodwin, E. (2017, October 25). I tried intermittent fasting — and it was one of the hardest things I’ve done. Insider. https://www.insider.com/i-tried-intermittent-fasting-how-to-start-what-it-is-2017-10
19 Sharp, A. (2022, August 18). Intermittent Fasting and Working Out | The Pros and Cons for Weight Loss. Abbey’s Kitchen. https://www.abbeyskitchen.com/intermittent-fasting-weight-loss-evidence-based-pros-cons/