Intermittent fasting. Are you tired of hearing about it yet? It’s a dieting and lifestyle trend that has become increasingly popular over the past decade. It seems like everyone is doing it, including several celebrities! Many claim that it is the easiest and most effective way to shed pounds, as well as increase energy, mental sharpness, and even prolong life. But what actually is intermittent fasting and how does it work? A few months ago, I gave IF a try to see what all the fuss was about. I also decided to do a little deep dive into the medical research to see what the experts really think about it.
What is IF and how does it work?
Fasting itself is not a novel concept. Humans have been fasting since the beginning of time. When you have to literally chase down your dinner before you can eat it, you’re not likely to get three square meals a day. And of course, there are those that fast for religious or cultural purposes. Intermittent fasting simply means that you are cycling between periods of fasting and feeding. According to IF experts, there’s a few different ways that you can structure your fasting/feeding cycle. Some advocate for a 16 hour fast and 8 hour eating period within each 24 hour day, others say the best way is a 24 hour fast 1-2 times per week. The most common proposed benefits being weight loss, decreased bloating, decreased appetite, increased energy and mental sharpness, as well as decreased inflammation and risk for diabetes.
But how exactly does it work? This part gets a little complex, but stick with me. When we eat, our food is broken down by enzymes in our gut and converted into molecules that are released into our blood stream. Foods that are high in simple carbohydrates like white rice and bread, are converted into sugar and used for energy. If our cells don’t need to use all that sugar, it’s escorted by insulin (a hormone secreted by the pancreas) to our fat cells and stored for later use. When our insulin levels drop (when we haven’t eaten in a while) those sugars are released from their little cell prison and used up for energy. When we gain weight, it’s partly because our insulin levels remain high and active so that the sugar can’t escape to be used up. The idea behind IF is that by fasting, we routinely allow our insulin levels to decrease so that our fat stores can be efficiently utilized. Phew…are you still there?? This is obviously a very simplified version of the science behind IF, but I think it covers the basics.
What does the science say?
There’s a decent amount of reliable evidence to support the proposed benefits of IF. Several human and animal studies have shown that IF combined with a healthy diet and lifestyle, allowed participants to lose weight during the trial by increasing insulin sensitivity and reducing insulin levels. Studies have also shown that IF can increase human growth hormone (HGH) which benefits fat loss and muscle growth, and facilitate increased cellular repair which allows the cells to clean out all the old proteins. Cool! When it comes to weight loss, IF yielded the best results with individuals classified as obese and those at risk for diabetes. While there are clearly benefits to IF, some experts also state that the weight loss benefit may be not be any better than any other diet involving a mild to moderate caloric deficit and addition of nutrient dense foods. It’s also important to note that trials have been largely short term, so it’s unclear what (if any) the benefits of long term IF would be.
Did IF work for me?
As I mentioned before, I’ve given IF a try a few times with the expectation that I would experience some weight loss. Spoiler alert…I didn’t. But I did find that I felt less hungry throughout the day and experienced less bloating. So, it wasn’t all bad! I attempted the most common form of IF; fasting for 16 hours and feeding for 8. Unfortunately, I just didn’t find it super sustainable for me mainly because I got so tired of CONSTANTLY thinking about food! Now, don’t get me wrong, I LOVE food. But, with IF, I found that I was constantly thinking about when and what I was going to eat. I realized that I dreaded when 7 pm would roll around every evening and I’d have to officially stop eating for the day. It got kind of exhausting and I felt like I wasn’t really enjoying my meals as much. I also found that I got a little obsessive with the “rules.” Like any diet or restrictive eating trend, it’s easy to go a little too hard. I found myself being so ridiculously strict with my eating and fasting times that I was literally staring at the clock, waiting for it to turn from 10:59 to 11:00 so I could eat. This is dumb…and not healthy. So my experience in a nut shell is that while I did notice some positive effects, I just didn’t find IF to be very sustainable for me.
Should you try intermittent fasting?
IF does seem to have some pretty impressive benefits that are supported by evidence. Is it a miracle diet that will work wonders for everyone? No. Simply put, it is a viable method to reach a weight loss goal if you find that it fits well with your lifestyle, values, and needs. The bottom line is that lifestyle change of any kind HAS to be sustainable. Some people are able to make IF a healthy and sustainable part of their lives and I think that’s awesome! But, It’s not going to work for everyone, and that’s ok!
If you do decide to try intermittent fasting, here’s a few things to keep in mind:
- You don’t have to perfectly follow the “rules” to feel or see a benefit. If you need to eat something 10 minutes after your feeding period ends, just do it! You’re not going to completely derail any progress you’ve made. Be aware of all-or-nothing thinking!
- Try starting with the 16/8 fast that we talked about earlier. This is a more simplified form of fasting and will be much easier for a beginner than going straight into a 24 hour fast.
- If you’re miserable…then stop! Like I mentioned, lifestyle change has to be sustainable. If you dread the idea of having to live like this indefinitely, then it’s not sustainable.
- If you decide it doesn’t work for you, don’t tell yourself you’ve failed!! You didn’t fail, you learned more about yourself and what you need to be successful. That knowledge is invaluable! Good for you!
- You should still be eating healthy foods. A common misconception with IF is that because you’re fasting, you can eat whatever you want during your feeding periods. Sorry, not true. Most of the studies that yielded weight loss results, combined IF with healthy foods and exercise. You still need to care for your body!
- Finally, there are some people who should NOT try intermittent fasting unless it has been specifically recommended by a physician. Those who are pregnant, breastfeeding, individuals with diabetes or who are underweight, children under the age of 18, and those with predisposition for an eating disorder or who have a history of disordered eating should avoid IF. If you have any other health condition, be sure to check with your physician as well!
So, to sum up, IF seems to work for some people who are able to make it a sustainable part of their lives, but it’s not for everyone. If you want to lose weight, have more energy, and feel more focused, but find IF too daunting, I recommending keeping things simple. Try a mild caloric deficit, focus on proteins that you enjoy, nourish your body with more vegetables, and move your body ever day. Most importantly, remember that consistency and patience leads to progress!
If you want more information about nutrition and healthy weight loss, or are interested in a personal health and wellness plan, please contact me about a free 30 minute coaching consultation.
Resources used for this article:
Monique Tello, M. (2020, February 10). Intermittent fasting: Surprising update. Retrieved August 25, 2020, from https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156
Anson, R. M., Guo, Z., Cabo, R. D., Iyun, T., Rios, M., Hagepanos, A., . . . Mattson, M. P. (2003). Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proceedings of the National Academy of Sciences, 100(10), 6216-6220. doi:10.1073/pnas.1035720100
Klempel, M.C., Kroeger, C.M., Bhutani, S. et al. Intermittent fasting combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Nutr J 11, 98 (2012). https://doi.org/10.1186/1475-2891-11-98
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. https://doi.org/10.1007/s13679-018-0308-9
Gunnars, K. (2020, April 21). Intermittent Fasting 101 – The Ultimate Beginner’s Guide. Retrieved August 25, 2020, from https://www.healthline.com/nutrition intermittent-fasting-guide