What does intermittent fasting involve?
Intermittent fasting, or IF, consists of alternating periods of fasting with periods of food intake. This technique has been shown in recent years to have multiple benefits for our body and our overall health.
Scientifically proven benefits
The benefits of intermittent fasting arise from a process that appears to activate autophagy. Autophagy is the natural renewal of our cells to get rid of those parts that aren’t working well and to give way to new components.
The description of the basic mechanisms involved in autophagy earned the Japanese scientist Yoshinori Ohsumi a Nobel prize in 2016. He used bread yeast to identify the essential mechanisms of the process and showed that they were similar in human cells.
In recent years, thousands of scientific studies have been conducted assessing the benefits of this practice in the human body. In fact, the NCBI International Scientific Studies Repository contains 232,410 studies related to intermittent fasting.
IF has been shown to help the immune system by stimulating expression of markers that identify infected or damaged cells. This way, the immune cells can go and eliminate them1.
In terms of disease, fasting has shown a positive effect in neurodegenerative diseases such as Alzheimer’s1, heart disease2, and liver and intestinal diseases3. It also promotes insulin sensitivity, protecting the pancreas and preventing diabetes mellitus4.
The effects of IF in cancer patients are still being studied. In some types of cancer, it appears to help the patient recover, but in other cancers, IF makes the tumor more resistant to the cancer treatments,1,5 making IF the subject of controversy and research.
In healthy individuals, fasting has been shown to help regulate weight, improve physical and mental performance, and improve mood1.
Ways to practice fasting
There are different fasting methods depending on the alternating periods. The best known are:
- 16/8: eating all meals in an 8-hour window during the day and fasting for 16 hours.
- 12/12: eating only during half of the hours of a day.
- 24: interspersing a full day of fasting between days of regular food intake.
- 48: Two full days of fasting between days of regular food intake.
If you decide to start intermittent fasting, it is very important that you do so gradually and listen carefully to your body. This will allow you to see what works best for you, to decide if it really feels good for you and if you notice any benefits in your body.
If you have any underlying disease, we recommend that you talk to your doctor and ask him or her if IF is right for you.
1Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev. 2017;39:46-58. doi:10.1016/j.arr.2016.10.005
2Malinowski B, Zalewska K, Węsierska A, et al. Intermittent Fasting in Cardiovascular Disorders-An Overview. Nutrients. 2019;11(3):673. Published 2019 Mar 20. doi:10.3390/nu11030673
3Bragazzi NL, Sellami M, Salem I, et al. Fasting and Its Impact on Skin Anatomy, Physiology, and Physiopathology: A Comprehensive Review of the Literature. Nutrients. 2019;11(2):249. Published 2019 Jan 23. doi:10.3390/nu11020249
4Grajower MM, Horne BD. Clinical Management of Intermittent Fasting in Patients with Diabetes Mellitus. Nutrients. 2019;11(4):873. Published 2019 Apr 18. doi:10.3390/nu11040873
5Mindikoglu AL, Abdulsada MM, Jain A, et al. Intermittent fasting from dawn to sunset for four consecutive weeks induces anticancer serum proteome response and improves metabolic syndrome. Sci Rep. 2020;10(1):18341. Published 2020 Oct 27. doi:10.1038/s41598-020-73767-w