A Guide to Intermittent Fasting
stedavies.com
stedavies.com
This is essentially false for anyone reading the article. The studies that showed mice living longer lives from calorie restriction were restricted from birth, and thus their growth was stunted, and smaller creatures live longer (think about dogs; big ones die earlier).
Studies of animals where the calories restriction was started mid-life all show increased mortality. The immune system and wound healing are compromised.
That being said, I've been using a system basically like Leangains since March for the purpose of losing weight. It's just cutting calories and I find that two meals a day plus a big plate of vegetables for dinner allows me to fast from Noon to breakfast the next day with minimal hunger.
But this is a calorie deficit/weight loss strategy because I'm overweight, not a lifestyle thing I'm going to keep up forever. And so far I've lost 29 lbs since March, so that's nice.
There are benefits to fasting occasionally I think, but that's not calorie restriction. It's just giving your body a 24 hr period to engage in autophagy and clear out some of the junk; you make up the calories on the other days.
Very true. People don't realize that calories don't "reset' after the day ends. Net calorie gain/loss is best measure on a weekly or bi-weekly basis. If you stay under target for 3 days then binge two full pizzas, you aren't actually going to lose anything.
I know, I fast regularly (I'm days 2 of a 5 day one at the minute) and I do eat quite a lot when I'm not fasting, and despite what everyone will tell you, I don't 'put back the weight immediately' -- even if I have a nice binge dinner on day 5.
In fact, after quite a few years of fasting very intermittently (I do perhaps 4 a year), I know I can't eat as much as I used to, and I don't 'creep' up as I used to when I started. I'm a LOT dryer than I was, and I can still enjoy a 32 ounce steak (!) when I feel like one.
Not many people incorporate 2-3 day fasts into their diet.
Do you eat your breakfast at 4 AM?
But when I purposefully eat as much as possible on vacations (trying out all of the famous places, you know), then for next week or two I get hungry all the time. It takes a lot of time before I could get back to my normal eating schedule. I really don't care one way or other but my busy schedule just get in the way of regular lunches.
Also I have been going to same doctor for last decade and he says my health is as great as of someone 15 years younger than me.
No, I eat when I sit down at my desk at work at 9 AM. It's part of my routine. I'm just busy in the morning so while I'm aware of being hungry I just do my stuff and my commute until I can sit down and enjoy my breakfast sandwich and black coffee.
I get a box of the frozen turkey sausage, egg, and cheese sandwiches at Costco and just grab one as I leave the house each morning.
Comparative analysis reveals that eating less beneficial in
adult and older primates but is not beneficial for younger
animals. This is a major departure from prior studies in
rodents, where starting at an earlier age is better in
achieving the benefits of a low-calorie diet.
-- http://news.wisc.edu/calorie-restriction-lets-monkeys-live-long-and-prosper/
Elephants live for 60 years. Mice live for 3. Life expectancy is clearly not a function of size alone, so you probably need to back up that claim that they lived longer because they were stunted.
For example, birds are the opposite: larger birds generally live longer than smaller birds.
Actually, the more I think about it, it's the same with lizards. And primates and most mammals. And pretty much every species besides a small subset of domestic canines that have undergone artificial selection in the past millennia.
e.g. "The researchers, Willcox etal, did not attribute this superior health to genetics because when younger Okinawans migrate to mainland Japan, Hawaii, or the United States, they soon acquire the chronic diseases of the host population. The Okinawans are shorter and weigh less than mainland Japanese, and men aged 87 to 104 years average 145.4 cm (4ft 9 in) and 42.8 kg (94lb)."
> Benefit #2. It helps with calorie restriction
No study cited that proves this. Only cites studies about the benefits of "proof" that caloric restriction helps longevity, but really is just a correlation.
> Benefit #3. It helps you lose weight and body fat
No study cited, follows up with "believe me, it worked on me".
Cites this study: "Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma."
That's incredibly specific and shouldn't be generalized to the general population.
>Benefit #5. It helps your cells clean and repair themselves
Cites studies made on rats/mice. Although that's a good indicator it might be mirrored in humans, it proves nothing.
> Benefit #7. It regenerates the immune system
Study was made on 3 day fasts, and not intermittent fasting.
It would nice if he pointed out those are potential benefits instead.
(disclaimer: I practice IF but take issue with this one claim, at least without the stipulation of hunger)
I also get a mental 'high' on day 3+4, but it goes down after that.
It also makes me more mindful of the process of eating. I don't think it ever really made the food itself taste better, but it was a good reset for the hedonistic treadmill.
It's like they discovered that if their stuff gets read by more critical-minded folks, those people expect proper science to back up claims, and they want to address that. That's a Good Thing, but: they set out to look for that science, and don't find proper peer reviewed studies which completely agree with their view. Then, instead of admitting their theory isn't backed by science (e.g. because it's too general, or just not proven, or just wrong) they collect articles/studies which are sort of related but in fact don't prove their points. I really wonder if they do this willingly, or just don't realize that is not how scientific evidence works.
> There is no scientific evidence to suggest fasting does any of the above...
You can never know that there's NO scientific proof for something because you can't even know for sure that you've read all the studies.
Others have already pointed out dubious claims about increased longevity. I'll take issue with section "Benefit #1. It supports with hormone regulation and lowers diabetes II risk." Sure eating less carbohydrates will lower your diabetes risk. But that doesn't mean you have to fast, just that you should eat less carbohydrates.
And contrary to what is written under that heading, insulin lowers high sugar levels, it does not cause them. High insulin levels are caused by high blood sugar. While it is plausible that fasting will lower your risk of diabetes, that's foremost because you're eating less and thus the glycemic load is lower. (Glycemic load is how much your blood sugar rises from food.) You can lessen the load by eating less in quantity or by refining carbohydrates less (by eating fruits instead of drinking juice, for example)
While I think that fasting is a valid and rather easy way of countering unhealthy eating habits, it is just one of many possible ways.
And this is no myth: "If you go too long without food your body will start eating itself (muscle)". The article lists this together with other myths, as if starvation weren't a real danger. Sure most people won't get any ill effects from not eating for a day (it's healthy for most) but once the fat is gone, muscle is next.
Flatly untrue. The article linked to "in proof" is about primate studies that suggest -- perhaps even strongly suggest -- that caloric restriction can slow the process of aging. This does not, however, rise to the level of proof, and certainly does not provide conclusive indication of what caloric restricters can expect more generally. The author is apparently willing to make this grandiose claim to a susceptible audience with nary a word about its limitations, which should set our alarm bells ringing.
If you want to calorically restrict, do it because you've thought long and hard about the consequences of a truly significant choice -- not because it's a tech industry fad.
Apparently it has to do with autophagy (https://en.wikipedia.org/wiki/Autophagy), which your body seems to enter when you restrict calories. IF apparently stimulates your body to perform autophagy due to the fact that you're timing your meals.
TBH, I still need to do my own research to see how much of this is real vs. pseudoscience, but I've noticed an improvement to my health. Whether that's placebo effect or not, remains to be seen.
As for IF, as you say, it is basically not proven to do anything (no 'phenomenon' at all). Simplest and most logical reason for success is because it helps people stick to their diet, by arbitrarily restricting the window of eating.
Opinion I read on r/leangains is that some people find it easier to e.g. just eat two 600-800 calorie meals within their IF window, rather than sticking to a diet that involves 3-4 smaller ~300-400 calorie meals, spread out through the day, none of which feel 'satisfying'.
I do IF, but that's because if I try to eat anything within 3 or 4 hours of waking up I feel nauseous and sleepy. I also find it easier to manage caloric intake by limiting my "feeding window" to 8 or 10 hours. There are also some fringe benefits such as refining my ability to self-deny indulgences and be more thoughtful around food choices. Simply put, if I tell my self "no food after 8pm" I won't binge eat two pints of icecream before bed.
The only diet that matters is that one you can stick to.
If IF helps you maintain your ability to comply to the diet you want, great, but there's absolutely no evidence for it being superior than the same diet spread over the day, and there a few ways in which it's probably suboptimal, like building muscle (although again not hugely so, so compliance probably trumps the small advantage you get).
If you're trying to lose weight, and you like food, the sight of the food in these 1200 calorie 3 meal daily plans is incredibly depressing. Eating an egg white on a piece of wheat toast every morning for the rest of your life is a kind of torture that never gets easier. It's like trying not to blink forever, or holding your breath forever.
Much better to just wait all day and spend the calories on a generous portion of something you really want to eat.
I suppose you mean "jog", but jobbing between places sounds very intense as well. :)
IF fits my lifestyle really well, since I only end up eating twice. I feel super energetic and focused while I'm fasted, and the lack of insulin spikes when I do eat have helped too. Besides losing weight, my overall health seems better. Cuts and injuries heal faster, less facial acne (I didn't have a lot to begin with though), and all of my stomach/intestinal issues are gone.
IF works really well for me, and I highly recommend that people try it for themselves for 1-2 months, to see if it works for them too.
What do 16/8 and 18/6 mean in this context?
I've given up a lot of foods (that made me feel horrible) and generally eat 1 meal around 11:30am and then snack in the evening. It's so nice getting the diet right. I feel so good now. All of my health issues were caused by foods (I recognize this isn't the case for everyone, but it's worth a shot).
Cutting out sugar is awesome. After I did it I really recognized that I was just maintaining a blood sugar high all day long.
I agree about stuff being tough to find, googling elimination diet are a whole lot of pop-health sites. They all have the right gist of how to do it though, just ignore the fluff. A little below this anchor [1] (closest anchor I could find) there is a how to do an elimination diet. That has a list of foods to avoid. Most people who have digestion issues have a problem with one or two FODMAPs [2], which are gluten, fructans, lactose, and legumes.
I highly recommend adding sugar and caffeine to the list of stuff you get rid of. You'll go through a little withdrawal but it can be a trigger. My digestion problems were caused by foods that were high in fructose. This meant high fructose corn syrup, artificial sweeteners that had a similar structure, and fruits with a high fructose to glucose ratio (looking at you, apples). This happened because I'm a celiac and eating gluten for years messed up my small intestine.
Due to sinus headaches I've cut out a lot of foods, doing so has also fixed all my digestion issues. The things causing my digestion issues were fructose and gluten. My brother is lactose intolerant but I can eat dairy all day long. Additionally, I've cut out caffeine, sugar, sodium nitrites, and MSG because they were triggers for sinus headaches.
I wish you success in finding the source of your problem. Getting your diet right is such a change in quality of life.
In essence it's calorie restriction on veggies for 2-6 weeks at a time supplemented with blood tests and physical activity. She (Dąbrowska) states that it resets the immune system, restricts cancer growth (or even puts cancers into recession), helps with diabetes and cures food intolerance.
Proof for it is provided as "I've seen people that improved". I'm highly skeptical about it as my vegan-celiac-fit family part got hyped for it and went through a 3 week run. They came back with anecdotal self-healing miracles.
The diet is around 600-700 kcal a day, low on sugar. Supposedly it stimulates autophagy giving all of the stated benefits (on top of cleansing out "toxins").
As a side note I found that food intolerance is in fashion recently. There's one (!) test offered in my area for it called the Food Detective (made by Cambridge Nutritional Sciences Ltd.). I'm highly skeptical of it too as there's no competition and I couldn't find any studies confirming it's effectiveness.
My main concern is the potential impact on the brain. I vaguely recall some study observing neuron loss during extended periods of starvation.
Also having some sensible studies to back it up (or debunk it) would be nice.
That said fasting in some form seems to have been with us for a few thousand years and it seems unlikely that it would be so widely documented and practiced across cultures and religions if there wasn't some benefits to it.
It seems to me you'd want to make some adjustments to types and amounts of calories to account for exercise, especially anything very taxing, like endurance training. But I haven't found any advice on this specific topic.
Calculate your TDEE (Total Daily Energy Expenditure) in a purely sedentary state. Then eat more than that on the days you exercise to compensate for the energy you burned.
That assumes your goal is to maintain your current weight.
This worked really well for me.
I don't really fast on purpose but I mostly eat one large meal a day (dinner). I workout in evenings before dinner.
I do snack if I get hungry maybe around 4PM. My snacks are usually Lay's chips. Sometimes, I get a Gatorade for gym.
I can lift about as heavy as if I had a big lunch but cardio is different story. If push myself as hard as one days when I had lunch or a lot snacks, I will start to see stars. I go a lot slower with cardio then. (Seeing stars or vision going white is sign of sudden drop in blood sugar level).
Intermittent fasting (or more specifically, following a loose version of the Renegade Diet) is where I landed.. and have been able to keep my weight steady while still making strength gains. In my opinion, it's a good choice who have a hard time controlling their food intake without the hassle of counting calories and/or macros. This way, rules are set, and then can look forward to ~4 hours of eating without restriction. I've pushed this feeding window to the limit, and to gain significant amounts of weight week over week, I basically had to eat until I physically sick for multiple days.
I've also had blood work done, with everything being normal since I started over a year ago.
My sport (track cycling) is very power intensive and has both strength and endurance components.
I have two eating periods on active days and one on my rest days. That seems to do me ok, but endurance has still been an issue.
As other people have mentioned, a lot of the claims made about IF aren't entirely backed by the research. Most experiments are with mice and usually use a more severe form of fasting that what is advocated. It's just another way to do caloric restriction which may work better than the previous 'best practice' of 'many small meals'.
Apparently you are my dietary twin. I came to this exact formula accidentally, though, as a result of calorie counting. I skipped breakfast because I could do that most easily. Then I decided lunch would be really light because that gave me the leeway to have a more satisfying dinner and feel completely full once a day. And I didn't want to take the risk of having a light dinner, being hungry, and being unable to get to sleep.
I ended up with the mix of protein- and vegetable-heavy dinner because I started reading the nutrition labels of absolutely everything. Then without seeking out a particular type of food, I tried to remember which foods seemed like a good combination of filling and low calorie. And protein and vegetables is what it ended up being.
Overall it has worked great. The types and amounts of food I eat feel normal now, and I feel good, and my ability to control my weight has surpassed all expectations.
So far I have almost lost 20lb without changing anything in my diet (I currently am 6ft and 200lb). I did not expect this result going in, but have been pleasantly surprised. Research shows that IF can lead to a slight weight loss, but nothing like what I have experienced-- so I wouldn't want anyone to think they can replicate my results. That being said, I would do this even if I did not lose weight because the health benefits are immense.
I generally eat 13-14 and again 18-19. and that's it.
References: http://sciencebulletin.org/archives/10692.html http://www.bbc.com/news/health-39070183
How is this just not just skipping breakfast? 3 times a week? I know lots of overweight people who do this, although it is easy to follow.
[1] Have not done any fasting, but recently started considering intermittent fasting.
Everyone 'fasts' for 8 - 12 hours just by sleeping anyway, so simply skipping one meal nearest sleep means you fast for about 16h a day.