The Impact of Intermittent Fasting on the Body and Mind

Throughout history, people have fasted for many more reasons than simple weight loss. Tracking back to our prehistoric ancestors, fasting was a common reality as we hunted for our next meal, often not knowing exactly when food would be available. Still common today, religious fasts have been long believed to provide mental and spiritual clarity. Healing the body and mind are both possible via intermittent fasting (IF).

We tend to take eating and dieting for granted. The power of food - what we eat and when we eat it - is grossly underestimated. The decisions we make around food affect our health beyond our weight - it can introduce changes that get passed down for generations.

Let’s look at the impact of simple changes to when we eat and how IF works in the body.

Effects of Intermittent Fasting on the Body

  • Blood: Decreased insulin, IGF-1, leptin; Increased ketones, adiponectin, ghrelin.
  • Brain: Improved cognitive function, neurotrophic factors, stress resistance; Reduced inflammation.
  • Fat cells: Lypolysis; Reduced inflammation.
  • Heart: Lower resting heart rate, blood pressure; Increased stress resistance.
  • Intestines: Reduced cell proliferation, inflammation.
  • Liver: Increased insulin sensitivity, ketones; Decreased IGF-1.
  • Muscle: Increased efficiency, insulin sensitivity; Reduced inflammation.

There is a process integral to fighting off diseases, like cancer, called autophagy. This process eliminates damaged cells.

Our bodies are designed to get rid of these cells because the inappropriate cells can go on and release proteins that are toxic to other healthy cells.

How does this process have anything to do with intermittent fasting, you ask? Studies show that regular, consistent eating can inhibit the process of autophagy. However, fasting seems to increase autophagy, removing toxic cells, and reducing the risk of cancer and brain disease.

Gaining Control with Intermittent Fasting

If you missed our posts about the Circadian Rhythm you might want to go back and check those out. Intermittent Fasting and the Circadian Rhythm go hand-in-hand when discussing the benefits of IF for overall health.

Let’s take a look at how a study on mice points us toward the effectiveness of IF and what conclusions we can draw from it.

One study allowed some mice to eat all day whenever they wanted. Keep in mind that mice are designed to eat at night (as dictated by their Circadian Rhythm). Other mice were allowed to eat the same amount as the all-day mice but were restricted to eating that amount during the ideal time (at night).

Guess what? Even though both groups of mice took in the same number of calories per day, the group that ate freely throughout the day were obese. Those who partook during appropriate feeding times for mice were fit. Some of the mice were allowed to eat whenever they wanted on the weekend and restricted during the week, they were still reasonably fit compared to those who ate all day, every day.

For those of you who like to see the numbers [both groups ate the same total calories]:

  • Mice with NO restrictions: 47g (18g of body fat)
  • Mice with TIME restrictions: 34g (4g of body fat)

We can translate these results to humans fairly easily. The Circadian Rhythms we all have offer the most appropriate, efficient time to eat (and digest or process food). If you are eating at the wrong times, like the obese mouse group, you will have an extremely difficult time losing weight.

Beyond weight gain or loss, the choices we make regarding when we eat can have impacts on other functions and even affect future children through epigenetics. Epigenetic changes to our cells through diet are passed down to our children - and in turn passed down to their children! For example, large-scale events that impact the diet of a large population, such as the Irish Potato Famine, caused epigenetic changes leading to an increased risk of disease in generations to come.

If we eat the way we are designed by nature, we can positively influence our bodies. By eating outside of the design (snacking regularly, a high number of meals per day, etc.), we change the natural rhythms coordinated by the suprachiasmatic nucleus (SCN). Changing these rhythms can lead to misalignment of our entire rhythm and lead to dysregulation.

Dysregulation can cause changes in genes like the CLOCK gene, which regulates other processes and genes. These changes can be made permanent over time and be passed down to offspring.

This may be a lot of heavy, depressing information if you know you eat outside the optimal time for eating. There is good news! Those obese mice we talked about before were returned to an appropriate time-restricted eating pattern. Guess what? They began to lose weight and regain the coordination they lost.

Intermittent fasting, specifically time-restricted eating, is more than a simple diet plan. It is an eating pattern that can improve your overall health by ensuring the appropriate control of your Circadian Rhythm.

A healthy clock ensures good function and good function leads to overall health and longevity. Our next post looks at the types of Intermittent Fasting and why time-restricted eating is the best method for maintaining a healthy lifestyle.