Here’s How Intermittent Fasting Impacts Your Body

In the mid-1960s, a Scottish man named Angus Barbieri fasted for more than a year. For a total of 382 days, he survived on liquids, vitamins, and some yeast, ultimately losing 276 pounds. He undertook the fast (under medical supervision) to lose weight in his pursuit of better health.

The practice of fasting for health benefits dates back to the fifth century B.C.E. when Hippocrates recommended fasting for certain illnesses. By the 1800s, fasting was being studied for its potential health effects. 

Intermittent fasting (IF) is the practice of restricting eating to certain times, also known as time-restricted eating. After a substantial time without eating, the body uses up its glycogen (sugar) stores and starts burning fat.

This process is known as metabolism switching. This leads to increased ketone levels, which stimulates weight loss. In addition to weight loss, IF can positively influence other aspects of health. 

Read More: The Science Behind Fasting Diets

Intermittent fasting can be practiced in various ways, each with its own unique schedule and benefits. While there are many methods, three of the most popular and widely adopted types of intermittent fasting are:

• The 16:8 Method: Eating is restricted to eight hours during the day, while fasting is observed for the other 16 hours.

• The 5:2 Method: People eat a generally healthy diet five days a week and fast two days a week. For those two days, calories are restricted to 500-600. Hydration options include water, black (unsweetened) coffee, and herbal teas

• The Eat Stop Eat Method: This method involved complete fasting (no food) for 24 hours, once or twice a week. Hydration must be maintained, with water being the preferred source. 

Read More: What Is OMAD and How Does Intermittent Fasting Work?

By periodically restricting food intake, the body undergoes various positive physiological changes. Research has demonstrated that intermittent fasting can positively impact several aspects of health, from metabolic function to brain health. Here are some of the notable health benefits of intermittent fasting:

Time-restricted eating offers several benefits for people with type 2 diabetes. Weight loss (when needed) is an important aspect of improving diabetes symptoms, and intermittent fasting was proven to be more effective than calorie restriction for diabetes patients.

IF also reduces blood sugar levels. This is related to improved insulin sensitivity, which is the way the body efficiently uses glucose. A review of 10 studies concluded that IF reduced blood glucose, insulin plasma levels, body weight, BMI, and other related factors. 

Brain function was boosted by intermittent fasting in a few ways. There was an improvement in mild cognitive impairment, known as MCI. This is a transitional stage in older adults, between expected memory decline and dementia. Another IF brain-related impact is increased production of BNFD, which is a brain-derived neurotrophic factor.

BNFD is related to the stimulation and control of neurons and synapses. Additionally, animal studies show promise in mitigating Alzheimer’s symptoms and reducing amyloid in the brain. Concentration, executive function, and memory have been boosted by time-restricted eating.

Intermittent fasting is associated with certain cancer-related benefits. It reduces IGF-1, which is a growth hormone linked to several types of cancer. By reducing IGF-1, the growth of cancer cells may be inhibited. Cancer recurrence was shown to be reduced among breast cancer patients who followed a nighttime time-restricted fasting regimen, in which they didn’t eat for more than 13 hours.

Additionally, in some people with cancer who were undergoing chemotherapy, IF reduced side effects and increased quality of life — and researchers believe there is potential for increased effectiveness of chemotherapy treatment.   

Inflammation is a normal part of the body’s immune response to illness or injury. However, when there’s excessive inflammation, it can generate harmful effects. Although more research is needed, there are some promising studies that demonstrate inflammation reduction through the use of time-restricted eating.

The lowering of monocytes, a type of white blood cell, is one way inflammation is hindered. Lowering oxidative stress (which is linked to several chronic diseases) is another way IF helps inflammation. A more recent link between the benefit of IF for inflammation is the increased production of arachidonic acid, which is an inflammation inhibitor.

This article is meant for informational purposes only. Be sure to speak to a medical professional before changing your health routine.

Read More: When Dieting, Should We Be Fasting Or Grazing?

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• Postgraduate medical journal. Features of a successful therapeutic fast of 382 days' duration

• StatPearls. Biochemistry, Glycogen

• Clinical Nutrition ESPEN. The effect of intermittent fasting diets on body weight and composition

• International journal of endocrinology. Effect of Intermittent Fasting Diet on Glucose and Lipid Metabolism and Insulin Resistance in Patients with Impaired Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis

• Nutrients. Intermittent Fasting Enhanced the Cognitive Function in Older Adults with Mild Cognitive Impairment by Inducing Biochemical and Metabolic changes: A 3-Year Progressive Study

• Archives of medical science. Brain-derived neurotrophic factor and its clinical implications

• Nutrients. Intermittent Fasting in Breast Cancer: A Systematic Review and Critical Update of Available Studies

• Frontiers in Immunology. Time-restricted feeding reduces monocyte production by controlling hematopoietic stem and progenitor cells in the bone marrow during obesity

Allison Futterman is a Charlotte, N.C.-based writer whose science, history, and medical/health writing has appeared on a variety of platforms and in regional and national publications. These include Charlotte, People, Our State, and Philanthropy magazines, among others. She has a BA in communications and a MS in criminal justice.