Effects of Intermittent Fasting on the Circulating Levels and Circadian Rhythms of Hormones

[helvella]

Obesity is a frequent topic. And there has considerable discussion about various ways of managing eating in order to help control weight. Of these, one of the most discussed in recent years has been intermittent fasting and variations.

In that context, several times members have asked about the relationship between thyroid hormones and intermittent fasting. We have had few solid items of research to quote. Now, a new paper, discussing this exact area is available.

Review Article

Diabetes, Obesity and Metabolism

Endocrinology and Metabolism 2021;36(4):745-756.

Published online: August 27, 2021

DOI: doi.org/10.3803/EnM.2021.405

Effects of Intermittent Fasting on the Circulating Levels and Circadian Rhythms of Hormones

Bo Hye Kim1,2, Yena Joo3, Min-Seon Kim4, Han Kyoung Choe5, Qingchun Tong6, Obin Kwon1,2,7

1 Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea

2 Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Korea

3 Seoul National University College of Medicine, Seoul, Korea

4 Division of Endocrinology and Metabolism, Department of Internal Medicine, Diabetes Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

5 Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea

6 Brown Institute of Molecular Medicine and Department of Neurobiology and Anatomy, McGovern Medical School of UTHealth, and MD Anderson Cancer Center & UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA

7 Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea

Abstract

Intermittent fasting has become an increasingly popular strategy in losing weight and associated reduction in obesity-related medical complications. Overwhelming studies support metabolic improvements from intermittent fasting in blood glucose levels, cardiac and brain function, and other health benefits, in addition to weight loss. However, concerns have also been raised on side effects including muscle loss, ketosis, and electrolyte imbalance. Of particular concern, the effect of intermittent fasting on hormonal circadian rhythms has received little attention. Given the known importance of circadian hormonal changes to normal physiology, potential detrimental effects by dysregulation of hormonal changes deserve careful discussions. In this review, we describe the changes in circadian rhythms of hormones caused by intermittent fasting. We covered major hormones commonly pathophysiologically involved in clinical endocrinology, including insulin, thyroid hormones, and glucocorticoids. Given that intermittent fasting could alter both the level and frequency of hormone secretion, decisions on practicing intermittent fasting should take more considerations on potential detrimental consequences versus beneficial effects pertaining to individual health conditions.

Keywords: Intermittent fasting; Circadian rhythm; Insulin; Thyroid hormones; Glucocorticoids

Full paper freely accessible here:

e-enm.org/journal/view.php?...

[LindaC]

Not before time! Thank you for this, helvella. This is interesting, to tie in circadian with IF.

Good for them to make a start... since CI-CO still seems to predominate much of medicine. Until I see 'weight gain CAN BE purely hormonal' in nature... as in not everyone stuffs their face or is ignorant on dietary requirements... one fine day, soon, eh?

[Miffie]

Bit of a read ! I may need to take more time and make a few notes on this one. I have used intermittent fasting for quite some time now and found results on diabetic bloods not as I had hoped to see. My HBA1c has gone up a lot on the last 6-12 months. I was questioning the link to low ferritin as a factor. Now you have supplied more food for thought. Thank you.