Intermittent Fasting: Here’s What (Probably) Happens to Your Insides

Whether you are an intermittent-fasting aficionado or someone who is teetering the line deciding if you should take the drastic calorie-restriction plunge, we’ve uncovered some interesting facts about this dieting trend. Keep in mind that most of the data out there pertains to animal studies, as human data on the topic are limited. For example, the size of major organs, such as the pancreas, heart, small intestine, and liver, shrunk in fasted birds through a process known as autophagy—when the body consumes its own tissue in response to starvation or disease. Also, intermittent fasting increases an animal cell’s resistance to free radical oxidation and stress, which essentially preps an organism for more effectively countering potential serious illness or nurturing subsequent recovery.

The exact circumstances (fasting duration, health status, gender, etc.) that may actually affect humans who fast to such a radical extent are unknown at this point. But findings such as this can help steer your understanding of how biological material can likely behave during intermittent fasting. A few of these science-based assertions about how intermittent fasting may affect your most vital organs are definitely something to think about.

Intestines

Of all the organs, the gastrointestinal tract shows the most dramatic changes in the shortest amount of time during intermittent fasting. Varying levels of nitric oxide in the gastrointestinal system help to regulate blood flow, mucus response, inflammation, and how food passes through the mouth to the colon. Nitric oxide discourages digestive responsiveness during regular feeding, but it tends to have the opposite effect in a food-restricted gut.

Your intestines become more sensitive during intermittent fasting—which is the perfect time for your system to address any lingering digestive issues by processing poorly digested food and eliminating residue, for instance. In fact, the time that it takes for the digestive system to process contents tends to increase in fasted environments. Digestive tissues decrease while the presence of food-processing enzymes remain throughout the fast—probably in anticipation of the next feeding.

Liver

The liver is a major organ that helps detoxify the body and composes biological compounds necessary for digestion and other integral life functions. The liver metabolizes glycogen. When this all-too-important function fails, metabolic disorders, such as diabetes, are likely to ensue.

Fasting encourages the depletion of glycogen reserves and triggers a fat-burning process known as ketogenesis, during which your fat tissues release fatty acids that the liver converts into ketone bodies. This can explain why loss of belly fat and fat loss, in general, are common effects of long-term fasting. During this time, ketone bodies replace glycogen as your body’s metabolic fuel source. Ever wonder how folks can fast for extended periods of time and not pass out? Ketones.

Heart

Adiponectin is a hormone that can protect the heart by encouraging blood flow to heart muscles, which can help prevent a heart attack. This hormone can potentially bolster restorative heart health, as well. During intermittent fasting, levels of adiponectin were shown to increase before and after heart attacks.

Fasting discourages heart tissue damage as well as inflammation, and it slows down a natural process known as apoptosis—which is the controlled death of individual cells that occurs over time. Intermittent fasting discouraged expansion of the left ventricle walls, especially. The left ventricle is the thickest heart structure, and it is responsible for pushing oxygenated blood to the rest of your body’s tissues. Improved blood flow, heart-growth regulation, and inflammation control during intermittent fasting decrease risks for high blood pressure, irregular heart rates, and thickening of heart structures—all major signs of chronic heart disease.

Brain

Intermittent fasting improves cognitive function, preventing both short-term and long-term memory loss. During intermittent fasting, the hippocampus region of the brain that is responsible for spatial memory and short-term and long-term memory showed substantial development in the tiny brains of old mice.

Just as with the heart, intermittent fasting promotes blood vessel health, and it improves blood circulation with the flow of oxygen throughout the brain, which helps to prevent stroke. Intermittent fasting stimulates the release of brain-derived neurotrophins, which are proteins responsible for the sound health of neurons that ensures proper brain signaling.

Proceed with Encouragement, but Caution

Adding to the good-health news surrounding intermittent fasting, many of the biological effects of this trend have proved to be long-term. On the flip side, however, weight loss that results from intermittent fasting is usually short-lived, especially if you gorge after a food break. Although digestive enzymes stick around during a fast, levels may plummet in certain individuals, which is why you should slowly ease back into eating—about 25% of your regular food intake especially during the first three days after a fast.

Also, loss of electrolytes and water dehydration tend to be the main threats to well-being during fasting in otherwise healthy individuals. Those with pre-existing medical conditions and pregnant women should practice extreme caution when restricting any amount of food from their diets. For best outcomes, always contact a physician to discuss the pros and cons of intermittent fasting within the context of your particular health needs before you restrict your sustenance for any length of time.