Intermittent Fasting: Fantastic or Fad?

What is IF?

Intermittent fasting is a pattern of eating characterized by abstaining from eating or drinking anything that contains calories for a certain period of time. The most common IF protocol is an ‘eating window’ of 8 hours, followed by a 16-hour ‘fast’, or a non-eating period. There are additional forms of intermittent fasting, including 14/10 hour windows, 18/6, and even 24,36, or 48-hour fasts spaced every other day, or weekly. This is a popular diet for weight loss, promoting autophagy (or the cleanout of cells), and assisting in digestion. There are many controversies surrounding this diet, suggesting that is actually a disordered pattern of eating. There is evidence that intermittent fasting can be beneficial for certain individuals, but it is not a diet for everyone.

Who Should NOT Try IF?

            Firstly, anyone with a history of an eating disorder should not attempt to intermittently fast. Because of the nature of the diet, not eating for a certain period of time followed by being ‘allowed’ to eat can be triggering. Individuals who are hypoglycemic should also not try this diet, as they may be subject to dangerously low blood sugar levels. It may also have a negative effect on hormone circadian rhythms ².

IF and Weight Loss

            IF is a popular diet to assist individuals with weight loss. It is likely the bulk of this benefit is seen due to decreasing overall caloric intake due to not eating for certain periods of the day, or skipping meals. In fact, most research comparing intermittent fasting protocols to calorie-restrictive diets found little to no evidence that IF protocols were superior in aiding weight loss ³. However, some individuals may find the structure of an IF protocol easier to stick to than general calorie restriction, and allow them more freedom in food choices due to needing to eat more of their calories in a shorter amount of time.

Health Benefits of IF

                  The additional health benefits of intermittent fasting go beyond the popular use of weight loss. For example, IF can lower biomarkers associated with metabolic syndrome, specifically glycemic variables ⁴. Fasting insulin levels, blood pressure, cholesterol, insulin, and LDL all may be improved by intermittent fasting ⁴. Additionally, IF may be helpful in the treatment of PCOS in women, as evidenced by a study in which the participants underwent an eating period of 8 hours and saw significant improvement in BMI, IGF-1, and improvement in menstrual cycle irregularity ⁵.

IF – Yes or No?

            Should you try intermittent fasting? It depends. If your goal is simply to lose weight, it is proven you can achieve the same results simply by reducing your caloric intake. However, for anti-aging benefits, to allow the digestive system to rest, to improve specific biomarkers, or to improve certain hormonal profiles, IF may be a viable option for a dietary pattern. However, the most effective diet is always the one that honors your body’s signals.

References:

1. Jahn C. Campus recreation staff discuss flaws with popular intermittent fasting trend. The Daily Nebraskan. https://www.dailynebraskan.com/news/campus-recreation-staff-discuss-flaws-with-popular-intermittent-fasting-trend/article_585c0cb8-9275-11eb-a579-a377959e9590.html. Published April 1, 2021. Accessed June 12, 2022.
2.  Kim BH, Joo Y, Kim MS, Choe HK, Tong Q, Kwon O. Effects of Intermittent Fasting on the Circulating Levels and Circadian Rhythms of Hormones. Endocrinol Metab (Seoul). 2021;36(4):745-756. doi:10.3803/EnM.2021.405
3. Rynders CA, Thomas EA, Zaman A, Pan Z, Catenacci VA, Melanson EL. Effectiveness of Intermittent Fasting and Time-Restricted Feeding Compared to Continuous Energy Restriction for Weight Loss. Nutrients. 2019;11(10):2442. Published 2019 Oct 14. doi:10.3390/nu11102442
4. Kunduraci YE, Ozbek H. Does the Energy Restriction Intermittent Fasting Diet Alleviate Metabolic Syndrome Biomarkers? A Randomized Controlled Trial. Nutrients. 2020;12(10):3213. Published 2020 Oct 21. doi:10.3390/nu12103213
5. Li C, Xing C, Zhang J, Zhao H, Shi W, He B. Eight-hour time-restricted feeding improves endocrine and metabolic profiles in women with anovulatory polycystic ovary syndrome. J Transl Med. 2021;19(1):148. Published 2021 Apr 13. doi:10.1186/s12967-021-02817-2