The Benefits of Intermittent Fasting
June 9, 2012 in Beyond Paleo, Food Issues, Hormone Regulation, Paleo Philosophy, Weight Loss/Gain
Intermittent fasting, or IFing, is a very popular strategy for stimulating healing, increasing longevity, balancing hormones, increasing energy and mental clarity and losing weight. If you’ve heard this term bantered around paleo circles and have been wondering what it’s all about, then wonder no longer!
How does Intermittent Fasting work? Intermittent fasting provides a variety of health benefits, predominantly due to stimulating a process call autophagy. Autophagy is the process by which a starving cell can reallocate nutrients from cell machinery that is not working optimally to fuel more essential cell processes. The cell degrades its own components, including damaged organelles, cell membranes and proteins, in a tightly regulated process. Autophagy can destroy viruses and bacteria within the cell that are resistant to other ways a cell might destroy them. It can even help the cell identify a viral infection that may have otherwise gone undetected. Autophagy plays a crucial role in immunity and inflammation, balancing the beneficial and detrimental effects of immunity and inflammation, and thereby may protect against infectious, autoimmune and inflammatory diseases. It may even prevent cells from becoming cancerous. Autophagy plays a normal part in cell growth, development, and homeostasis, helping to maintain a balance between the synthesis, degradation, and subsequent recycling of cellular products. In fact, failure of autophagy is thought to be one of the main reasons for the accumulation of cell damage and aging. Turning on autophagy is extremely beneficial (whether it’s turned on by intermittent fasting, exercise, ketosis, or straight calorie-restriction). The result is healthier, more efficient cells, which means a healthier, more efficient body.
What are the benefits of Intermittent Fasting? The benefits of intermittent fasting can be inferred from the effects of autophagy. However, more and more scientific studies are being conducted to confirm the effects of Intermittent Fasting and also isolate the optimal strategy for putting it into practice. Many of the benefits listed below have not been directly tested in humans using Intermittent Fasting; however, there is either strong evidence from animal studies or evidence from studies of autophagy itself, combined with anecdotal evidence to support these claims. The benefits of Intermittent Fasting include:
- Increasing lifespan.
- Increasing insulin sensitivity, which has many health benefits in and of itself. Of interest, the resulting increase in insulin signaling in the brain is thought to be how fasting/calorie restriction works to increase lifespan.
- Lowering blood lipids, triglycerides and other markers of metabolic syndrome.
- Fighting/preventing cancer. There is also some evidence that fasting before chemotherapy treatments can help reduce the negative side effects.
- Increasing growth hormone secretion (which builds muscle and burns fat).
- Normalizing expression of the hunger hormone ghrelin, thereby reducing appetite.
- Promoting brain and peripheral nervous system health by increasing neuronal plasticity and promoting neurogenesis, which has a large variety of effects such as boosting mood, memory, and mental clarity.
- Increasing dopamine production, thereby boosting mood and increasing anticipation and response to rewards (meaning we get more enjoyment from less food).
- Increasing energy through regulating metabolic hormones.
Intermittent Fasting is a little like hitting a reset button. It can help curb sugar cravings, restore energy, and even promote deeper sleep.
How do you do it? And how often? There are many options, but in general fasting for at least 16 hours is required to receive any benefits. Fasting beyond 24 hours doesn’t extend those benefits. So consider a fast anywhere between 16 and 24 hours. This includes sleep time, so a great way to intermittently fast is to simply skip breakfast. Ideally, that also means skipping your morning coffee. Drinking water is okay. Expect to feel hungry when you fast. This is different than simply listening to your body’s cues and waiting until you are hungry to eat (although many people are opportunistic about when they fast and simply choose days when they aren’t that hungry anyway). If you want to fast for 24 hours, you can skip breakfast and lunch. In terms of frequency, it is perfectly safe to fast 2 or 3 times per week (in the absence of health conditions that might complicate matters). If you prefer a longer fast, then once or twice per week is fine. Some people opt to have an 8-hour feeding window every day (see Leangains). However, I would argue that a daily fast is no longer intermittent. The body is able to adapt and predict the fast and many of the benefits are dulled. I also want to point out that you can benefit from fasting even if you do it very infrequently. Perhaps you only want to fast once per month, or once every few months. There is no clear evidence that fasting frequently will dramatically improve your health. Try it, see how you feel, see how you feel when you try it the next time, and then decide what is best for you.
What should you break fast with? When you are ready to eat, eat a balanced meal with lots of great protein and tons of veggies. You probably won’t feel very good if you eat too many carbs, so I urge caution with starchy vegetables and fruit. And don’t overdo the quantity you eat; try and aim for a normal meal (or only slightly larger than normal). I actually found in my own experimentation that I wasn’t that hungry and would eat an unusually small meal to break fast (I would then have more appetite for the meal after that).
Is fasting for everyone? The answer to this is a resounding NO! If you are not getting enough sleep or if your stress is not well managed, you may experience exaggeratedly high cortisol production in response to fasting, which can be detrimental. If you have a history of metabolic derangement or adrenal fatigue, I urge caution for the same cortisol-spiking reason. Women may be more likely than men to have an exaggerated cortisol spike in response to fasting (here‘s a great post reviewing women-specific responses to fasting). If you are not currently eating a fairly low carbohydrate diet (say, less than 100g per day), then fasting may have some side effects that mask the benefits (like headaches, fatigue, and nausea, caused by high cortisol). If you have any grains or dairy in your diet, you may experience a withdrawal-like effect because you aren’t consuming the opiate-like substances found in those foods. If fasting does not feel good, then don’t do it. If fasting feels good the first few times, but then stops feeling good, then stop. My own personal experience with intermittent fasting led me to realize that I can only get away with doing a 16-hour fast once or twice per month. Any more frequently and the cortisol spike stops weight loss, wrecks my sleep, and makes the whole experience completely pointless.
I have a question for you, unrelated to fasting. My husband and I have been doing paleo and are trying to work 6 children into it.. What is your take on kids and almonds? Can they get too much of it? They are very used to the SAD, but not processed. I made lots of waffles, pancakes, and bread. All 100% whole wheat, then started leaning to gluten freee. Can kids get too much of almond baked goods? I was trying to limit it to once a day. Any suggestions would be greatly appreciated! Thank you.
Jessica
Well, I certainly think that almond-flour baked goods are WAY better than grain-based baking. But I’m not a big fan of eating too many almonds (or other nuts high in phytic acid and omega-3 polyunsaturated fats). I try as much as I can to get my kids used to eating meat, veggies and fruit as the basis of their diet, but there are many times where some paleo baking makes the difference between them eating willingly and a complete battle (they like paleo toast beside their poached eggs, for example). And I have noticed that a nut-based snack (as opposed to a fruit-based snack) gives them much more even energy, especially in the afternoon. I try to mix it up with more coconut products and more nut-free baking as a way of minimizing the nut intake. And I am continually encouraging them to eat something like a piece of fruit and a hard boiled egg as a snack as opposed to a paleo granola bar. That being said, my kids do get something nut based anywhere between 1 and 3 times per day (with the intention that we will slowly wean off the nuts once the other aspects of them eating paleo are a little easier). I hope this helps!
Intermittent fasting is absolutely great! I’m doing it since November and let me tell you my personal experience. The first few ones were tougher, i felt dizzy and hungry.
After a couple fasts, my body got used to it and I even enjoyed my fast days. I was doing 2x24h per week. I am more focus on my work, it cleared my skin, i can see my abs now and it cuts the grocery bill by 10-20%. Great article!
Intermittent fasting is great! I’m doing it since November and let me tell you my personal experience with it. The first few ones, I felt dizzy and hungry. After a couple times, my body got used to it.
The benefits for me : more focused on my work, cleared my skin, a lot more energy during the day ( because there was no insulin spike) and reduced grocery bills.
Great article !
I’m sorry for the double post, the first one told me Error when I published it. Feel free to delete it and delete this explanation comment.
No worries. Thanks for your comments! It’s really neat how well your body adapted to fasting (mine didn’t! although I always felt good doing it).
I too have seen wonderful results from fasting.. biweekly for 24 hours. and I feel great. I was taking vitamins the first few times then stopped.. large glasses of water really are essential to make it…great information!!!
I’m in my fifties and am in my perimenopausal cycle. Fasting puts my symptoms at a normal level… No night sweats, sugar spikes, water retention. 24 max with some afternoon walks for 30 minutes and I am loosing my belly fat. So girls, drink lots of fluids (no caffeine) , breathe deeply and I’ll see you on the other side of living young.
At this time I am ready to do my breakfast, afterward having my breakfast coming again to read additional news.
I noticed you advise IF without coffee. What do you thing about Mark Sissons post: http://www.marksdailyapple.com/fasting-questions-answers/#axzz2MKVfOQcz
Where he says the opposite?
This is my first time posting on your site although I have been following it for ages. Just wanted to say THANK YOU! I love your blog and can hardly wait for your book!
Thanks, Jackie
My worry with coffee is that both Ifing and coffee stimulate cortisol sectretion. If you’re someone with really great sleep and stress management and perfect cortisol regulation, the combination is likely beneficial. But, I think many people experimenting with IFing don’t have really tight cortisol regulation and the addition of coffee can derail efforts by causing cortisol to spike too high.
is it okay to have a protein shake in the morning though? a whey protein isolate. specifically Iso-100
If you have protein or carbs, it’s not fasting.
wow. where to start. just stumbled onto your site. I’ll have to write again later about my entire life of IFing!! I’m a 60+yr old plain ordinary paleo dad, professional plant ecologist (I know all about grains, legumes, and nightshades), who’s had amazing results with ‘standard’ paleo (my psoriatic nails – thickened, pitted, yellow, deformed, fall-off) are now at 1 year clean and clear, and i’ve had no arthritis symptoms since the end of week 2. EVERYTHING about my mind and body works better. More on all that later if you’re interested. But my asthmatic wife won’t go there. Would paleo help long term asthma’s effects? Should she perhaps even go AIP? She eats all the paleo meals I fix (most of the time as I’m also a stay at home dad with a 5 year-old stop doing the math), but still insists on her oats, pasta, bread, cheese, occasional potatoes, and cream her coffee (haha, I had to give up coffee on Day 3). Oh, and she’s a ‘super-taster’ so coconut stuff has to be toned way down (although she likes my home-made coconut milk ‘yoghurt’) . She’s practically there, but what alternative bread/scone/muffin type thing can I get her addicted to, and how can I get her to eat more meat? Maybe you have a recipe for Chinese paleo pork dumplings? and, my gosh, thank you for your site; I’ll probably be up all night now browsing.
Yes, paleo will help her. I’d try and get her onto standard paleo first (or nightshade-free paleo) before tackling the AIP. Check out my baked good recipes. Lost of bread and muffins to get you started.
You dont talk much about IF in parallel with working out. If I was wanting to do a shorter (16h) IF on a day that I was working out, what would the timing of the day before and the day of look like? (What time to stop eating the night before, what time to work out, etc) .. I typically do my workouts in the morning somewhere btwn 9-10a. And within the 8 hour window of eating, how much should I eat? Should I eat roughly the same amount of calories as normal? Or should I just eat my lunch, snack, dinner, snack same size as normal?
This really isn’t my area of expertise.