2604: The Benefits of Long Term Fasting - Intermittent Fasting Effects on Metabolism & Inflammation

[00:00:00] It's another Q&A edition of Optimal Health Daily, Episode 2604, and I'm Dr. Neal Malik. Hey there, welcome back to another Friday show where I answer your questions. On all the other days, I read health and fitness blogs to you like an audiobook,

[00:00:15] and with permission from the authors, of course. Now, I'll let you know how you can send in your own question at the end of the show and get rewarded for it, but for now, let's hear today's

[00:00:25] question and start optimizing your life. Today's question came via email. Tina writes, Hi Dr. Neal, love your podcast, it's taught me so much. My question is about 72-hour fasts. I've completed this twice, and I feel like it's helped with inflammation. My joints seem to feel

[00:00:46] better. But is there any valid scientific studies to back this apparent effect of 3-day fasting? Thank you so much for taking the time to send in your question, Tina, and I'm so glad that you enjoy this podcast and find it helpful.

[00:01:00] So, let's start with what the term fasting means and the different types of fasting. By definition, fasting means the complete avoidance of food. Intermittent fasting, which has gained popularity, means that we still eat but with differing lengths of time between

[00:01:16] meals and snacks. Now, there are lots of variations of intermittent fasting programs. Some programs suggest limits on how many calories you can eat. For example, some may allow one meal during a so-called fasting day. That makes up 25% of your calorie needs for a typical

[00:01:33] day. So, let's say you need to consume 2000 calories per day. This would mean that your one meal on a fasting day should be about 500 calories, not very much. So, in general, there are three types of intermittent fasting diets specifically. There's the alternate day

[00:01:52] fast. This is where we alternate between days we can eat what we want and days we're supposed to fast. Then, there's whole-day fasting, which would be fasting one to two days per week.

[00:02:03] And then on the other days, we can eat anything, anytime. Now, in your case, Tina, it sounds like you've tried a version of whole-day fasting where you extend the fast to three days. Then, there's time-restricted eating. This involves a routine where we only have a certain number of

[00:02:18] hours to fast and a certain number of hours to eat daily. So, now we ask ourselves, does intermittent fasting have any health benefits? There are some studies that have found benefits such as weight loss, reduced body fat, and lower total blood cholesterol levels. And this all sounds

[00:02:35] really great. On the other hand, researchers have also found that intermittent fasting may be just as effective as watching what you eat and reducing your daily calories. And I should mention many of the studies on intermittent fasting were performed using animals as participants.

[00:02:51] And we know that animals behave very differently than we do. But more human studies are being conducted. And what they're finding is short-term intermittent fasting may reduce body weight and body fat because by fasting, the body's going to rely on fat stores for energy. This has been shown

[00:03:09] especially within the first 24 hours of fasting and seems to peak between 18 and 24 hours of fasting. Fasting has also been shown to increase metabolism in the short term. Now, does it help with inflammation? I should first mention that there are claims out there that fasting helps remove toxins

[00:03:29] from the body. If you do encounter this claim, and let's say even this source is backed by science, they are likely quoting studies performed in animals. And again, since our bodies are different

[00:03:41] from animal bodies, we can't put much stock in these claims yet. We need more human studies to know what's really going on. Okay, so let's go back to this idea of reducing inflammation. Does

[00:03:53] fasting help with that? One study looked at whether fasting over the course of 10 days led to inflammation throughout the body. And this study was really well designed. It was highly controlled, meaning they made sure that their study participants actually ate zero calories for those 10 days.

[00:04:11] Now, in case you're wondering how those participants possibly survived, the researchers did allow them to consume water and gave them a multivitamin every day. They then drew blood samples from each participant to see how their bodies responded. They found that this type of fasting actually led to

[00:04:28] increased inflammation throughout the body. Now, while these results are interesting, the issue is that most people don't fast like this, meaning people fast, again, intermittently. So instead of not eating for 10 days straight, most will stop eating for a day or two or three in your case,

[00:04:45] Tina, then they'll go back to eating normally again. So other studies have found that fasting may actually help those that experience chronic inflammatory conditions. For example, those with rheumatoid arthritis may experience some relief by fasting. In fact, a meta-analysis found that

[00:05:04] intermittent fasting helps reduce inflammation when compared with control groups. What was interesting about this meta-analysis was that those that were overweight or obese and were consistent with their intermittent fasting programs for at least eight weeks tended to see the best results.

[00:05:21] So, these researchers believed that reduced inflammation among those with overweight and obesity may be more pronounced because those with overweight or obesity may have more inflammation throughout the body to begin with. That means those with other inflammatory conditions like

[00:05:39] inflammatory bowel disease or in your case, Tina, joint pain, may be more likely to experience reduced inflammation after following an intermittent fast. The trouble is, once the fast is over and we

[00:05:52] return to our regular diets, we see that inflammation levels tend to go back to where they were before the fasting began. So what does this all mean? Where does that leave us? Basically, it's telling

[00:06:06] us the immune system and inflammation throughout the body is very complex. It may be that whether fasting is anti-inflammatory or not is more about how we're fasting, whether we have any pre-existing conditions, and our other lifestyle behaviors like what we eat when we're not fasting and our stress

[00:06:26] levels and our exercise routines. So all of this to say that if you find that fasting makes you feel better and fasting isn't causing you harm, go for it. But there are those that should avoid most

[00:06:39] forms of fasting altogether. These would include those with diabetes, those with low blood sugar, the elderly, children, those that are pregnant and breastfeeding, and swimmers. You don't want to end up with low blood sugar in a body of water. And of course, check with your personal physician

[00:06:57] before making this part of your lifestyle just to be safe. Thank you again for taking the time to send in your question, Tina, and I'm so glad you enjoy the show. Now, if you want to send your

[00:07:11] questions in and get a copy of our Optimal Living Daily Workbook for doing so, you can email them to health at oldpodcast.com. That's health at oldpodcast.com. Or if you want your voice played on the show,

[00:07:27] come by oldpodcast.com slash ask. You can also do it the old-fashioned way and call in your question. The number is 1-61-ILOVE-OHD. That's 1-614-568-3643. Thank you so much for sending in your questions.

[00:07:51] Answering them is one of my favorite parts of this show. And that'll do it for another Q&A edition of Optimal Health Daily. Thank you so much for listening every day and all the way through.

[00:08:00] I hope you have a great start to your weekend, and I'll see you back here tomorrow where your optimal life awaits.