14 Benefits of Intermittent Fasting (How It Works, Tips, and Possible Side Effects)

Intermittent fasting is the latest buzz in the nutrition and diet industry. It provides excellent results without requiring you to follow a stringent regimen. There are multiple benefits of intermittent fasting, and it does not require you to give up your favorite food or count calories. It is simple enough for everyone to adopt.

You could try different intermittent fasting (IF) plans to determine what works best for your metabolism and overall health. Some people combine IF with a ketogenic or low-carb diet for added weight loss benefits.

How Does Intermittent Fasting Work?

While there are several intermittent fasting methods, they all revolve around setting specific eating and fasting windows. [1]

For instance, 16/8 fasting indicates fasting for sixteen hours daily and eating only during an eight-hour window. With the rising popularity of IF, there are a host of intermittent fasting plans being introduced by health experts. And so, you can engage in an IF plan that fits your lifestyle.

According to Mark Mattson — renowned for his research on IF, after a few hours of not eating, the body starts burning fat instead of glycogen. Something he aptly refers to as “metabolic switching.” [2]

If you are trying to lose weight, intermittent fasting can help by giving you more time to burn the calories you consume in a day and switch to the fat-burning mode.

Intermittent Fasting Health Benefits

There are several proven health benefits of intermittent fasting, some of which are listed below. 

1. Helps In Losing Weight

Intermittent fasting boosts weight loss by lowering your insulin levels while increasing your HGH (Human Growth Hormone) and norepinephrine (noradrenaline) levels, leading to increased fat breakdown and energy expenditure. [3]

2. Induces Secretion of Hormones

Intermittent fasting induces the secretion of many hormones by the adrenal cortex, which is good for the body. These include glucocorticoids, or cortisol, which helps the body manage carbohydrates, proteins, and fat; aldosterone, a mineralocorticoid that assists the kidneys in regulating salt in your body; and androgens and estrogens — the sex hormones.

These hormones help regulate reproductive functions and general growth throughout adolescence. [3]

3. Maintains Blood Sugar Level

In recent decades, type 2 diabetes has become extremely common. Insulin resistance is a hallmark of this condition, which causes persistently high blood sugar levels.

Intermittent fasting is linked to significant improvements in insulin resistance and a remarkable decrease in blood sugar levels. [3]

4. Reduces Inflammation

Aging and the development of numerous chronic diseases begin with oxidative stress caused by free radicals. When free radicals come in contact with other molecules, particularly those of biological significance like proteins and DNA, they cause damage.

Intermittent fasting can strengthen the body’s defenses against oxidative stress. Research has also shown that intermittent fasting can aid in the battle against inflammation, a significant contributor to many types of chronic illness. [4]

Intermittent fasting has been shown to lessen oxidative stress and inflammation. It helps prevent aging and a wide range of diseases. Cortisol secretion also has anti-inflammatory effects.

5. Controls Heart Diseases 

Heart disease is one of the leading causes of fatality worldwide. It is well established that different biomarkers (so-called “risk factors”) are linked to a higher or lower risk of cardiovascular disease.

Numerous health issues like high blood glucose levels, arterial stress, inflammation, and low-density lipoprotein (bad) cholesterol have been shown to improve by switching to an intermittent fasting diet. Notably, many of these conclusions rely on research conducted on animals; more research on the effects of fasting on human heart health is needed before making any conclusive recommendation.

However, this does not take away from the multiple studies that have shown the importance of intermittent fasting in reducing cardiovascular risk factors like blood pressure, cholesterol, triglycerides, and inflammatory markers. [5]

6. Fights Insomnia 

It is well-known that your diet can affect your alertness and drowsiness; anyone who’s slipped into a food coma after a large meal can attest to this. 

People who practice intermittent fasting (IF) claim it helps them get a good night’s rest. Why? The circadian rhythm, which controls sleep duration, gets influenced by IF. [6]

7. Helps You Live Longer

Intermittent fasting, like continuous calorie restriction, can improve your longevity. Several age-related diseases, including fatty liver disease and hepatocellular carcinoma, can be delayed by following an IF diet. [7]

8. Beneficial For Your Brain

Several metabolic factors essential to brain health are enhanced by intermittent fasting.

There is evidence that intermittent fasting promotes the development of new nerve cells, which has implications for cognitive performance. Brain-derived neurotrophic factor (BDNF) is a hormone in the brain that is elevated during fasting. A lack of BDNF has been linked to mood disorders like depression. [8]

A stroke is another type of brain injury that can be prevented by intermittent fasting. Intermittent fasting can significantly improve brain health. It may help prevent brain damage while also boosting neuronal growth. [9]

9. Reduces Cholesterol

Several IF plans improve cardiometabolic health markers like LDL (“bad”) cholesterol and blood pressure. According to the CDC, LDL cholesterol can increase the likelihood of developing cardiovascular disease or stroke. Researchers also found that IF lowered triglyceride levels, which are blood fats that can increase the risk of cardiovascular disease, stroke, and heart attack. [10]

10. Maintains Blood Pressure

According to a study involving 1,422 participants, those who abstained from food for 4-21 days saw their systolic and diastolic blood pressure drop. [5]

It is because fasting can stimulate parasympathetic activity, also known as a “rest and digest state,” which is beneficial for digestion and aids in reducing blood pressure.

11. Lowers Insulin Resistance

Fasting allows your body to use up its fat reserves. Improving insulin resistance requires regular depletion of stored fat (especially glycogen). You can tap into your body’s stored energy by increasing the time between meals. It reduces hunger and, in turn, improves your insulin resistance. [3]

12. May Prevent Cancer 

Unchecked cell growth is a hallmark of cancer. The metabolic benefits of fasting are well documented and can translate into a lower cancer risk.

Animal studies have shown promise for using intermittent fasting and fasting-like diets to prevent cancer. Similar results have been found in human studies, though more research is required to verify these claims. Fasting has also been shown to mitigate some adverse effects of chemotherapy in humans. [11].

13. Keeps Your Cells Healthy

Several physiological changes occur when you go without food for an extended period. Autophagy is a critical cellular repair process initiated by the body. It is the process by which the body removes dead and damaged cells.

14. Boosts Memory 

Alzheimer’s disease occurrence, which is characterized by severe memory loss, exceeds any other neurodegenerative disease worldwide. Evidence from animal studies suggests that intermittent fasting may slow Alzheimer’s disease progression and lessen its severity. IF aids cellular regeneration throughout the body, including in the brain. People in the early stages of Alzheimer’s and even healthy individuals can benefit from a memory boost by following an IF diet. [13]

Are There Any Downsides To Intermittent Fasting?

Here are a few drawbacks of intermittent fasting:

1. Headache

Headache is a common intermittent fasting side effect and typically occurs during the first few days of a fasting protocol. [14]

2. Nausea

You can experience nausea during fasting due to hunger and eating non-nutritious meals. Also, if you follow a low-carb, high-fat diet, your body may take longer to increase the bile production needed to digest high-fat meals, which may lead to constipation and nausea.

3. Digestive Problems

Constipation, diarrhea, and bloating are some digestive issues that can arise due to intermittent fasting. Eating high-fiber nutrient-dense foods may aid in avoiding this condition.

4. Dehydration 

During the first days of fasting, the body excretes water and salt through urine. It is called fasting natural diuresis. You could experience dehydration if you do not replace lost fluids and electrolytes.

You should monitor the color of your urine to ensure proper hydration. It should be lemonade-pale, as dark urine is a surefire sign of dehydration.

5. Malnutrition 

Malnutrition can result from prolonged fasting and inadequate nutrient intake. If you do not plan or practice your fasting program carefully, you may experience malnutrition and other health complications. It’s crucial to eat well while intermittent fasting. You should never over-restrict calories.

Tips For Making Intermittent Fasting Healthy

These pointers will help you reap the benefits of intermittent fasting more quickly:

1. Do Your Research 

Find the right intermittent fasting plan for yourself. It could be periodic fasting, time-restricted eating, or alternate-day fasting. Start slowly so you can get used to fasting and make necessary adjustments after analyzing your progress.

2. Keep Yourself Hydrated 

Besides water, keep hydrated throughout the day with zero-calorie beverages like herbal teas, lemon water, etc.

3. Rest and Relax

You should avoid exercises of any intensity on fasting days. However, gentle practices like yoga may be helpful.

4. Eat Filling and High-Volume Foods

Foods like raw vegetables and fruits high in water content, like grapes and melons, are satisfying and low in calories.

5. Count Your Calories 

Choose high-protein, high-fiber, and low-saturated-fat foods. Protein-rich foods like beans, lentils, eggs, fish, nuts, and avocados are a few examples. You could use meal-logging apps like MyFitnessPal to track your daily calorie intake.

6. Check With Your Healthcare Expert If You Are On Medication

You do not necessarily have to be off medication if you wish to start intermittent fasting. You can check with your doctor to align your eating window with your medication. Read more about medication and fasting here. 

Check Out: How to Get the Most Out of Your Fasting Routine [Tips from Experts]

Who Should Avoid Intermittent Fasting?

Intermittent fasting is a great way to lose weight and improve your health. But it’s not for everyone. If you have any of the following conditions, it may not be suitable for you:

1. Pregnant Women

Women engaging in IF while pregnant or nursing could harm the baby’s development. A baby’s health and milk supply depend on the mother getting enough calories during pregnancy and breastfeeding. 

2. Teenagers

Intermittent fasting is not advisable for teenagers, as it is more than likely to result in them adopting unhealthy eating habits that may be difficult for them to break later.

3. People Who Have Had Eating Disorders

Intermittent fasting is strongly linked to bulimia nervosa. Bulimia nervosa is an eating disorder characterized by binge eating and purging behaviors. So, people at risk of falling into eating disorders should avoid fasting diets. 

4. Immunodeficiencies

Those coping with a severe illness or people who have recently recovered should not engage in IF without consulting their doctor. Maintaining lean body mass and a functional immune system is crucial for people with illnesses or compromised immune systems, which usually depends on consuming enough calories.

5. People With Dementia or Other Brain Injuries

If you have dementia or any other form of brain-related ailment or brain injury, you should consult your physician before contemplating intermittent fasting.  

Frequently Asked Questions

Wrapping Up

Numerous scientific studies support the benefits of intermittent fasting. IF can help reduce the risk of cardiovascular disease and improve weight loss, blood sugar regulation, and much more.

However, there are some potential side effects of intermittent fasting. These are not prominent and are easily manageable. But people with eating disorders and pregnant and breastfeeding women should avoid IF.

References

1. “Intermittent Fasting: What Is It, and How Does It Work?” Intermittent Fasting: What Is It, and How Does It Work? | Johns Hopkins Medicine, 20 Oct. 2022.
2. “Mattson, Expert on Brain Aging, Science of Fasting, Retires.” NIH Record, 23 Aug. 2019.
3. Kim, Bo Hye, et al. “Effects of Intermittent Fasting on the Circulating Levels and Circadian Rhythms of Hormones.” PubMed Central (PMC), 27 Aug. 2021.
4. Graef, Franziska A., et al. “Fasting Increases Microbiome-based Colonization Resistance and Reduces Host Inflammatory Responses During an Enteric Bacterial Infection.” PubMed Central (PMC), 5 Aug. 2021.
5. Allaf, Mohammed, et al. “Intermittent Fasting for the Prevention of Cardiovascular Disease.” PubMed Central (PMC), 29 Jan. 2021.
6. Alves, Alexessander Couto, et al. “Fasting and Time of Day Independently Modulate Circadian Rhythm Relevant Gene Expression in Adipose and Skin Tissue.” PubMed Central (PMC), 7 Sept. 2018.
7. Qi, Jie, et al. “Fasting Induces Hepatocellular Carcinoma Cell Apoptosis by Inhibiting SET8 Expression.” PubMed Central (PMC), 19 Mar. 2020.
8. Caliyurt, O. “Relationship Between Fast-acting Antidepressant Properties of Total Sleep Deprivation and Serum BDNF Levels | European Psychiatry | Cambridge Core.” Cambridge Core, 16 Apr. 2020.
9. Phillips, Matthew C. L. “Fasting as a Therapy in Neurological Disease.” PubMed Central (PMC), 17 Oct. 2019.
10. “Clarity on Cholesterol Management and Why We Need It | Blogs | CDC.” Clarity on Cholesterol Management and Why We Need It | Blogs | CDC, 10 Apr. 2015.
11. Tiwari, Sagun, et al. “Effect of Fasting on Cancer: A Narrative Review of Scientific Evidence.” PubMed Central (PMC), 10 Aug. 2022.
12. Godar, Rebecca J., et al. “Repetitive Stimulation of Autophagy-lysosome Machinery by Intermittent Fasting Preconditions the Myocardium to Ischemia-reperfusion Injury.” PubMed Central (PMC), 23 June 2015.
13. Toledo, Françoise Wilhelmi de, et al. “Unravelling the Health Effects of Fasting: A Long Road From Obesity Treatment to Healthy Life Span Increase and Improved Cognition.” PubMed Central (PMC), 10 June 2020.
14. “The Fasting Headache | National Headache Foundation.” National Headache Foundation, 13 Sept. 2018.

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