In this series, we started to discuss different fad diets in an attempt to determine which of them, if any, truly help with weight loss and what health effects they may or may not have. We have already discussed gluten-free, paleo, and keto. This week, we explore Intermittent Fasting as we conclude our examination of diets.
What is Intermittent Fasting?
IF, as it is sometimes abbreviated, is literally fasting for periods during the day (or an entire day) as opposed to a prolonged period of time (several days, for e.g.). The goal is to take a break from eating by either using a ratio that adds up to 24 hours; e.g. 14:10, 16:8, 20:4 (the first number represents the amount of time that you fast for, and the second is your eating window), fasting for a full 24 hours once or twice a week, or taking alternate fasting days (with a greatly reduced caloric intake, e.g. 25% of normal) with “normal” eating days(1).
What we think it does:
We believe that it increases human growth hormone production (resulting in better fat loss and muscle gain), improves cellular repair(2), reduces insulin levels (slow fat storage, therefore burning more calories)(3), and improves gene expression (genes that aid in longevity, for example)(4).
What it actually does:
By reducing the amount of time you spend eating, you reduce your caloric intake. Therefore, you create a caloric deficit. This nutritional habit is mostly safe for a healthy person. In fact, people fast for religious/spiritual and mental health reasons all the time. However, the reality of this diet is that the drop in food intake can affect people who are prone to acid reflux/heartburn (both positively and negatively)(5), who may be pregnant (not enough research on this, though), who may have an eating disorder(6) or, in general, anyone who has a pre-existing condition that may rely on timing your meals throughout the day.
How to safely try IF:
First things first, consult your doctor. They may be able to tell you the risks of any type of fasting based on any health issues you may have. Also, read up on it as much as possible. Once you start, start with a ratio that is easy to maintain (as going too hard from early may be a bit too extreme for you and your body may rebel, causing extreme hunger and binging). Slowly go further and further until you find something you can manage. The goal here isn’t to avoid hunger — you will feel hungry, very hungry. The goal is to pick a method and find a ratio that doesn’t send you crazy with hunger. Also, don’t feel the need to do your fasting every day. Any reduction in caloric intake will result in weight loss.
Having covered four fad diets, it’s easy to see two things — the real purpose of going gluten-free should not be weight-loss, and the other three simply work by reducing your caloric intake. One can actually compare them in terms of efficacy and safety and draw one’s own conclusions. There are lots of other nutritional approaches out there, but the bottom line among all that actually work is that if you want to lose weight, you need to create a caloric deficit. Just make sure to do as much research as possible and consult your doctor, a qualified and certified personal trainer, and a nutritionist or dietitian before starting any new weight-loss plan.
1. Mary-Catherine Stockman, RD, LDN, Dylan Thomas, MD, Jacquelyn Burke, MS, RD, and Caroline M. Apovian, MD (2018). Intermittent Fasting: Is the Wait Worth the Weight?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5959807/#S4title
2. Benjamin D Horne, Joseph B Muhlestein, Jeffrey L Anderson (2015). Health effects of intermittent fasting: hormesis or harm? A systematic review
https://academic.oup.com/ajcn/article/102/2/464/4564588
3. Monique Tello, MD, MPH (2018). Intermittent fasting: Surprising update
https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156
4. Aftab Ahmed, Farhan Saeed, Muhammad Umair Arshad, Muhammad Afzaal, Ali Imran, Shinawar Waseem Ali, Bushra Niaz, Awais Ahmad & Muhammad Imran (2018). Impact of intermittent fasting on human health: an extended review of metabolic cascades
https://www.tandfonline.com/doi/full/10.1080/10942912.2018.1560312#_i3
5. Honor Whiteman (2015). Fasting: Health benefits and risks
https://www.medicalnewstoday.com/articles/295914
6. Liz Meszaros (2020). The dangers of intermittent fasting
https://www.mdlinx.com/article/the-dangers-of-intermittent-fasting/6CZfO5sYFDWi4wK2OPRiEd