You may have heard of intermittent fasting and wondered what
the hype was about. Intermittent fasting (IF) is ultimately a way of eating
that has gained popularity over the past few years because it can help you lose
weight. This is because IF works by restricting when you can eat and when you
fast. There are many forms, including time-restricted fasting (i.e. fast 16
hours, eat eight hours) and fasting every other day (Stockman, Thomas, Burke,
Apovian, 2018). So is IF just another fad diet or could it be a healthy
lifestyle change?
Normally, blood glucose levels rise after eating a meal and return
to homeostatic levels within a few hours via insulin. With IF, normal
physiological responses are still present after consuming a meal, but noticeable
differences occur during the fasting state. When a person is in a fasting
state, their body has depleted all its glucose stores for energy, thus the body
will start to utilize ketones and fatty acids (Malinowski et al, 2019). The
fatty acids are the result of lipolysis of triglycerides and its precursor diacylglycerol.
This causes changes in a person’s lipid profile (lower triglycerides levels and
low density lipoproteins) and results in weight loss (Malinowski et al, 2019).
So what other affects does IF have on a human? Another
common benefit seems to be reduction of inflammation. Malinowski et al (2019)
looked at the effects of IF on inflammation in regards to atherosclerosis. Atherosclerosis
is an inflammatory disease caused by plaque accumulation in arteries. They
learned that IF resulted in increased adiponectin, an anti-inflammatory and
anti-atherosclerotic protein secreted from adipocytes (Malinowski et al, 2019).
Stockman, Thomas, Burke, and Apovian (2018) also noticed that some inflammatory
markers were reduced in subjects who followed an IF diet. This is beneficial to
know when treating patients with inflammatory diseases.
So should IF be promoted more to patients? Although these
benefits seem great, there just isn’t enough data to make a definitive statement
saying we should or we shouldn’t be promoting IF. Therefore, we as a scientific
community, must push for large populational studies to be done in order to
really understand the effects of IF. This can help us who to recommend this
diet to, who not to recommend to, and who to closely monitor. However, these
are promising results and could possibly be a good addition to future treatment
plans.
References
Malinowski, B., Zalewska, K., Węsierska, A., Sokołowska, M.
M., Socha, M., Liczner, G., Pawlak-Osińska, K. ,Wiciński, M. (2019).
Intermittent Fasting in Cardiovascular Disorders-An Overview. Nutrients, 11(3),
673. doi:10.3390/nu11030673
Stockman, M. C., Thomas, D., Burke, J., & Apovian, C. M.
(2018). Intermittent Fasting: Is the Wait Worth the Weight?. Current obesity
reports, 7(2), 172–185. doi:10.1007/s13679-018-0308-9
Interestingly, intermittent fasting has also shown good results for cardiovascular health. A research group looking at intermittent fasting for Ramadan (a muslim fasting tradition where individual do not eat from dawn to dusk) utilized an observational study to determine if cardiovascular health improved. As expected they found a reduced BMI after ramadan from 28.4 kg/m2 to 27.7 kg/m2. They also found that the patients systolic blood pressure was decreased from 132.9 mmHg to 129.9 mmHg although no change was seen in the diastolic blood pressure. Finally, based on the Framingham risk score, there was a significant improvement in the 10 year coronary heart disease risk after the month of fasting than before, going down by 2.2 points. This suggests that intermittent fasting could have benefits for patient with a higher risk of cardiovascular disease.
ReplyDeleteNematy, M., Alinezhad-Namaghi, M., Rashed, M., Mozhdehifard, M., Sajjadi, S., Akhlaghi, S., Norouzy, A. (2012). Effects of Ramadan fasting on cardiovascular risk factors: A prospective observational study. Nutrition Journal, 11, 69. https://doi.org/10.1186/1475-2891-11-69
Hi Cindy, I have always wondered about the risks and benefits to IF. This past summer, my grandma had to undergo an aortic valve replacement. Before the surgeons could do the surgery however, they had to run tests on her arteries to make sure she didn't have any arterial buildup. After running the tests, the surgeons told my grandma how surprised they were that her arteries were so clear. For a 75 year old women, they said that her arteries had the buildup of someone in her 30s. They explained that part of it was probably due to her diet, and another part of it might have to do with the fact that she practices intermittent fasting for religious holidays. I had always wondered how IF worked and why that could potentially lead to decreased plaque accumulation in the arteries, so I really enjoyed reading about those studies in your post.
ReplyDeleteHi Cindy, The topic of IF has fascinated me ever since one of my cousins, a doctor from the Philippines, recommended it to me. She seemed more inclined to recommend the time restriction diet over the energy restrictive one. I am curious to see which form of restriction is more effective on weight loss and by extension overall health. I found this article that seems to discuss the two that you may be interested in. DOI: https://doi.org/10.1017/S0029665116002986. It seems the largest problem with the energy restriction in which you eat every other day, is that many people are often very hungry during the fasting period. Due to this problem, the long term sustainability does not seem as feasible. In contrast, the time restriction seems to be more feasible as many people practice it during Ramadan. Ultimately, I think this was a great topic to bring up.
ReplyDeleteI found your post to be really relevant with me being Iranian, and coming from a Muslim background. Although I never partook in Ramadan by choice, unless I was physically present in Iran during it, my mom fasts every year and continuously tells me that it is good for your health. I never looked more into this until now. I found it interesting that the GI tract actually uses the time you are fasting to basically reset and repair itself. Additionally, since intermittent fasting allows to lower blood pressure, I wonder if this would be something people with hypertension should try out more.
ReplyDeleteIntermittent Fasting: Is it Right for You? (n.d.). Retrieved October 14, 2019, from https://healthblog.uofmhealth.org/wellness-prevention/intermittent-fasting-it-right-for-you
This is interesting as to the different positives and advantages of taking up intermittent fasting as a part of your diet. I researched some other positive outcomes from intermittent fasting and found that when paired with chemotherapy there have been some studies providing evidence to maintaining cancer-free health (Lv, 2014).
ReplyDeleteI am curious if it needs to be a regular thing in order for it to work effectively and properly due to the body going into starvation mode which burns extra fat cells that are stored, but if consuming food and too much after the starvation period (since you likely will be very hungry) were to occur, would it have the opposite effect than intended due to your body storing fat cells more since your body is coming out of that starvation mode thinking it needs more?
References:
Lv M, Zhu X, Wang H, Wang F, Guan W (2014) Roles of Caloric Restriction, Ketogenic Diet and Intermittent Fasting during Initiation, Progression and Metastasis of Cancer in Animal Models: A Systematic Review and Meta-Analysis. PLOS ONE 9(12): e115147. https://doi.org/10.1371/journal.pone.0115147