Intermittent Fasting: A Scientific Explanation of the Amazing Health and Weight Loss Benefits and Practices

Introduction

In recent years, Intermittent Fasting (IF) has gained popularity as a diet for health improvement, weight loss, and longevity. By alternating periods of eating and fasting, IF provides a variety of health benefits. This article explores the science behind intermittent fasting and delves into its mechanics and benefits.

What is Intermittent Fasting?

Intermittent fasting is a diet that alternates periods of eating and periods of fasting. The emphasis is not on what you eat, but when you eat it.IF there are several methods, the most popular being the 16/8 method (fast for 16 hours and eat within 8 hours) and the 5:2 method (restrict caloric intake for two non-consecutive days and eat normally for five days).

16/8 Method:

In this method, the fasting period is divided into a 16-hour fasting period and an 8-hour eating period. For example, one would fast from 8:00 PM to 12:00 PM the next day and consume food during the 8-hour period from 12:00 PM to 8:00 PM. You will eat only lunch and dinner during that time, with the same amount of food as you normally eat. It is important not to eat extra food that you do not eat in the morning and to eat foods that are particularly rich in nutrients.

5:2 Method:

In this method, participants eat normally for five days a week and then drastically limit their caloric intake for the remaining two days of the week. During the two days of caloric restriction, the caloric intake is approximately 25% of normal caloric intake (e.g., 500-600 calories). Perhaps one meal per day would be just fine. The two days of caloric restriction should be non-consecutive and should be chosen to include nutritious foods.

Scientific Basis for Intermittent Fasting

Weight loss and fat loss
Intermittent fasting has been found to be an effective strategy for weight loss and fat loss; a 2018 systematic review and meta-analysis of six randomized controlled trials (RCTs) found that IF significantly reduced weight and body fat, especially in overweight and obese individuals led to (1)

Improved insulin sensitivity
IF improves insulin sensitivity and lowers blood glucose levels, which is especially beneficial for people with type 2 diabetes A 2014 study demonstrated that IF improved insulin sensitivity and reduced oxidative damage in mice (2) Another study in 2018 demonstrated that IF improved insulin sensitivity in human participants and showed that IF improved insulin sensitivity and reduced body weight in human participants (3).

Improved Brain Health.
Intermittent fasting may also have positive effects on brain health. Animal studies have shown that IF improves cognitive function, reduces oxidative stress, and enhances neuroplasticity (4); IF has been shown to prevent cognitive decline in a rat model of Alzheimer’s disease (5); and IF has been shown to improve brain health in a rat model of Alzheimer’s disease (6).

Autophagy and Cell Health
Autophagy is a natural process by which cells remove and recycle damaged components IF has been shown to stimulate autophagy, leading to improved cell health and reduced inflammation A study published in Autophagy in 2010 showed that IF induced autophagy in human cells induces autophagy in human cells (6).

Potential Effects on Longevity
Some studies suggest that IF may contribute to increased longevity: a study published in Cell Metabolism in 2019 found that IF significantly extended the lifespan of mice (7). While further studies are needed in humans, these findings suggest that IF may play a role in promoting longer, healthier lives.

Conclusion.

Intermittent Fasting is an increasingly popular diet strategy backed by accumulating scientific evidence. Studies have demonstrated that IF results in weight loss, improved insulin sensitivity, improved brain health, and increased autophagy. On the other hand, there are also indications of disadvantages, such as the risk of gallstones. Further research is needed to fully understand the long-term effects of IF and its potential for longevity. However, current evidence suggests that IF may be a powerful tool for improving overall health.

1 Harris L, Hamilton S, Azevedo LB, Olajide J, De Brún C, Waller G, Whittaker V, Sharp T, Lean M, Hankey C, Ells L. Intermittent fasting interventions for treatment of overweight and obesity in adults: a systematic review and meta-analysis. JBI Database System Rev Implement Rep. 2018 Feb;16(2):507-547. doi: 10.11124/JBISRIR-2016-003248. PMID: 29419624.

2 Valter D. Longo, Mark P. Mattson
Fasting: Molecular Mechanisms and Clinical Applications, VOLUME 19, ISSUE 2, P181-192, FEBRUARY 04, 2014

3 Sutton EF, Beyl R, Early KS, Cefalu WT, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metab. 2018 Jun 5;27(6):1212-1221.e3. doi: 10.1016/j.cmet.2018.04.010. Epub 2018 May 10. PMID: 29754952; PMCID: PMC5990470.

4 Mattson MP, Moehl K, Ghena N, Schmaedick M, Cheng A. Intermittent metabolic switching, neuroplasticity and brain health. Nat Rev Neurosci. 2018 Feb;19(2):63-80. doi: 10.1038/nrn.2017.156. Epub 2018 Jan 11. Erratum in: Nat Rev Neurosci. 2020 Aug;21(8):445. PMID: 29321682; PMCID: PMC5913738.

5 Shin BK, Kang S, Kim DS, Park S. Intermittent fasting protects against the deterioration of cognitive function, energy metabolism and dyslipidemia in Alzheimer’s disease-induced estrogen deficient rats. Exp Biol Med (Maywood). 2018 Feb;243(4):334-343. doi: 10.1177/1535370217751610. Epub 2018 Jan 7. PMID: 29307281; PMCID: PMC6022926.

6 Alirezaei M, Kemball CC, Flynn CT, Wood MR, Whitton JL, Kiosses WB. Short-term fasting induces profound neuronal autophagy. Autophagy. 2010 Aug;6(6):702-10. doi: 10.4161/auto.6.6.12376. Epub 2010 Aug 14. PMID: 20534972; PMCID: PMC3106288.

7 Mitchell SJ, Bernier M, Mattison JA, Aon MA, Kaiser TA, Anson RM, Ikeno Y, Anderson RM, Ingram DK, de Cabo R. Daily Fasting Improves Health and Survival in Male Mice Independent of Diet Composition and Calories. Cell Metab. 2019 Jan 8;29(1):221-228.e3. doi: 10.1016/j.cmet.2018.08.011. Epub 2018 Sep 6. PMID: 30197301; PMCID: PMC6326845.