What is intermittent fasting, and what does it do?
Despite its recent surge in popularity, fasting is a centuries-old practice that plays a central role in many religions and cultures. Defined as abstinence from all or some foods or drinks for a certain period, there are many different ways of fasting.
The most popular one is intermittent fasting (IF), which involves cycling between periods of eating and fasting, and it can range from a few hours to a few days at a time.
There are many ways intermittent fasting may benefit the body, but it’s important to talk to a healthcare professional before undertaking it.
This article lists and explains some backed-up benefits of intermittent fasting. Let’s get started!
1. Weight loss
Most current studies indicate that intermittent fasting may be an effective way to lose weight. It’s unlikely to be more beneficial than the classic calorie restriction, but some may find this type of fasting easier to maintain long-term.
A trial conducted in 2017 compared the impact of IF and a traditional calorie restriction diet on weight loss over one year. It turned out that both forms of dieting were similarly effective for weight loss. Moreover, there were no significant differences between the two groups for other indicators of health, such as heart rate or blood pressure.
2. Improved heart health
Cardiovascular disease is considered the leading cause of death worldwide, making up an estimated 19 million deaths globally in 2020. Improving your diet and lifestyle is one of the most effective methods to reduce your risk of heart disease.
Some studies have found that intermittent fasting could improve aspects of cardiovascular health. According to a review from 2016, IF could lead to a decrease in the following in both animals and humans: heart rate, blood pressure, triglycerides, and cholesterol.
It’s important to note that tryglycerides are a kind of fat present in the blood that is associated with heart disease. Basically, people with low levels of triglycerides are less likely to develop cardiovascular diseases.
3. Better cognitive function
Though data is mostly limited to animal research, multiple studies have found that fasting could have a beneficial effect on brain health. Animal studies from 2018 and 2021 have shown that fasting could protect brain health and boost the generation of nerve cells to help enhance cognitive function.
Moreover, fasting was found to help relieve inflammation (we’ll talk about this at No. 5), which could also aid in preventing neurodegenerative disorders. In particular, animal studies indicate that fasting may improve outcomes for and protect against conditions such as Parkinson’s and Alzheimer’s disease.
However, more studies are needed to establish the effects of fasting on brain function in humans.
4. A lower risk of type 2 diabetes
Intermittent fasting may also have benefits for diabetes prevention. Besides its potential benefits for heart health and weight management, research also shows that IF can also reduce insulin resistance, which is a major marker of type 2 diabetes.
Having overweight or obesity is one of the primary risk factors for developing type 2 diabetes. In other words, weight loss can help prevent a person from developing type 2 diabetes, particularly if they have prediabetes.
A 2022 review showed that intermittent fasting can reduce insulin resistance. While more research is needed, the findings so far indicate that the reduced calorie, or energy, intake can lead to decreased insulin production. However, the review stated above pointed out that there’s a lack of scientific evidence to confirm that intermittent fasting is more effective than traditional caloric restriction.
5. Fighting inflammation
While acute inflammation is a natural immune process meant to protect your body from infections, chronic inflammation can seriously affect your health.
Studies show that inflammation may be involved in the development of chronic conditions, such as rheumatoid arthritis, heart disease, and cancer. Some studies have found that intermittent fasting can help lower inflammation levels and promote better health.
One 2022 review of 18 studies also found that intermittent fasting could considerably reduce levels of C-reactive protein, which is a marker of inflammation.
6. Changes to the function of genes, cells, and hormones
There are several changes that occur in the body when you don’t eat for a bit. As already mentioned, intermittent fasting makes blood insulin levels drop, which promotes fat burning.
It also changes your body’s hormone levels to make stored fat more accessible. Some studies also found that intermittent fasting boosts cellular repair, such as by removing waste material from cells.
The human growth hormone (HGH) levels in the blood may increase as well, which promotes muscle gain and fat burning and provides other benefits. Additionally, changes to several genes happen that are beneficial to longevity and disease protection.
7. A reduced risk of cancer
Animal studies also indicate that intermittent fasting may help lower the risk of cancer. A series of recent animal studies suggest that restrictive diets, like intermittent fasting, could delay the onset of tumors. However, no current studies have confirmed any links between IF and cancer in humans.
According to the World Health Organization, obesity is a big risk factor for various cancers. This means the weight loss aspect of intermittent fasting may be a potential explanation why some studies hint at a reduced cancer risk.
So, there are some signs that IF may reduce the risk of cancer. However, experts point out that further research on humans is needed to support this claim.
8. Could extend longevity
Several animal studies have reported promising findings about the potential lifespan-extending effects of intermittent fasting. One 2021 study took a look at the effects of periodic fasting on the human digestive system and found that fasting boosted the diversity of beneficial bacteria in the gut microbiome, including the Christensenella species, which are linked to longevity.
The experts also noted a spike in sirtuins, proteins involved in metabolic regulation that are also related to longevity.
Animal research and a 2021 review of older humans have yielded similar results, reporting that fasting could be beneficial in delaying disease and boosting longevity.
However, further research is needed to understand how fasting may impact aging and longevity in humans and which fasting plans are most effective.
By the way, if you want to learn more about intermittent fasting, here’s a beginner’s guide that will give you all the information you need. Don’t forget that it’s important to talk to your doctor before doing this.
9. Help prevent Alzheimer’s disease
A 2023 review found that the physiological changes that happen during intermittent fasting may delay the onset of Alzheimer’s disease.
Animal studies from 2019 also suggested that incorporating intermittent fasting into your diet may help protect yourself against other neurodegenerative conditions, such as Huntington’s disease and Parkinson’s disease. However, more research is required to verify if this translates to humans as well.
10. May increase the effectiveness of chemotherapy
A review published in the American Cancer Society Journal points out that intermittent fasting may decrease toxicity from chemotherapy in some people.
However, experts note that more high-quality clinical trials are needed and recommend that patients undergoing cancer treatment only do any type of fasting as part of a clinical trial. For some types of cancer, it could potentially have a negative effect.
Another review of test tubes and animal studies suggests that fasting could increase chemotherapy’s effectiveness and reduce tumor progression.
Despite these promising findings, additional research is needed to look at how fasting may influence cancer treatment and development in humans.
If you liked our article on intermittent fasting, you may also want to read Myths Debunked: Bad Nutrition Advice Dietitians Want You to Forget.
