For years, I assumed the same thing, that "fasting" meant experiencing significant hunger. I always associated it with going entirely without food for some vague amount of time that was probably some consecutive number of days. But three weeks ago, after some Googling, I began what is called 'intermittent fasting'. Since it's only been three weeks, all I can say personally about the benefits is that I'm still doing it and have no plans to stop in the future, but I can say that by the third day, the hunger issue was negligible.
At its simplest, for men it means eating all your food for the day in a roughly eight-hour window, often noon to 8pm. (There is apparently some scientific thought that women may have significantly different needs; I really can't speak to that.) In practical terms, this translates to "skipping breakfast" and avoiding midnight snacks. This turns out not to be that difficult, but has definitely had an positive impact on me, so far. Discomfort-wise for me, I tend to get a bit of a rumbly tummy around 10am, but generally it subsides pretty quickly and even by 11am I can easily go for another couple of hours without even thinking about lunch if I get busy. It is far from constant hunger. (But I won't lie and say it's zero... just, negligible. Literally. It can easily be neglected and it will in fact go away.) I can also say that I'm hardly watching the clock in the evening and trying to judge whether it's the crack of 8pm yet or not... I often eat at noon-thirty or 1pm and then dinner at 6pm and am done thinking about food for the day, without any willpower expended. It just happens.
I say this mostly to point out to people that there is something to investigate that they may have misconceptions about, as I did. I will fully and up-front admit once again I am not in a position to extol its benefits particularly. (I like to do something like this for at least a couple of years before I do that.)
(But I will go slightly out on a limb and say that I would not be all that surprised to discover that "intermittent fasting" has somewhere between 80-120% of the benefit of the scientifically-studied high caloric-restriction diets, with much lower willpower and discomfort costs. It turns out that if you dig into those, we've really only studied "normal (modern) diet", "heavily calorically restricted", and sometimes a particularly unrealistic fasting schedule (see link), so if you're interested in a point in the middle of the two we've studied, you're sort of scientifically on your own. Hence the possibility I cite of 120%; currently it would fit the two data points we have just fine for it to turn out that "caloric restriction" isn't the optimum and is in fact overshooting.)
I've lived my life this way since I was a teenager, as does the rest of my close family. I've never liked breakfast, and late-night snacking has never been my forte. At this point in my life, I don't experience hunger unless I've gone a full 24 hours without eating, which basically never happens. I struggle to understand when people talk about having intense "cravings" for food, to the point where they throw away their health trying to satisfy that. Modern society's relationship with food seems to be broken (consider that 2/3rds of our population are overweight or obese), and I have to thank my parents for giving me a leg up on that one.
Cravings for food are not hunger. It's more like addiction. And that's the main reason we find it hard to lose weight - not the feeling of hunger, but cravings that are there whether we're hungry or not.
I wonder about food cravings. I get them sometimes and they are less of a craving for food and more of my mood suddenly being extremely unstable and an inability to focus. This is something of a problem that I have had for several years I don't know if maybe I have something medically wrong with me. I am in excellent shape and work out regularly but I am very heavy (240 lbs) so it might be I just need a very large caloric intake and I don't eat enough at each meal.
Cravings are very much related to what you eat and don't eat. Cut out all sugar from your diet and pretty soon you'll be dreaming of cake and frosting. Overdose on sugar and you'll be hungry again two hours later.
I accidentally stumbled into this by just being too lazy to eat in the mornings (also a lot of anxiety that, at the time, reduced my general appetite). I've found that the morning stomach rumblings can usually be resolved with a glass of water every hour or so. Since I'm also trying to be active, the extra emphasis on hydration is doubly beneficial.
With regards to this form of diet, I've found it to be successful for keeping me from overeating, and I rarely run into days when I think, "Man, I should've had more to eat." (NB: These days do happen, but they're usually days when I'm unusually physically active, like going for a run and two 1+ hour martial arts classes in the same day. That is, things that most people won't encounter and that an extra serving of protein at lunch probably would've resolved.)
So I'll go out a bit more on a limb, and observe that A: I had some lightweight metabolic illness (ate bad as a child, ate better as an adult but definitely had lingering effects) and B: I really don't seem to anymore, noticeably so even after three weeks. I can eat a lot more carbs and even a bit of outright junk, and I'm still losing weight right now. (While successfully exercising for strength gain.) That was not true two months ago; I had to rigidly stick to my low-carb regime, and any deviation plumped me right back up. Again, I'm still not ready to call it after three weeks, but the thought is certainly stirring in my head that this could be a nontrivial element of the obesity problem, and a nontrivial reason why dieting often seems to hit a plateau early and often, before it really should. In theory, even in our current food environment, it ought to be possible to get pretty close to our natural, optimal weight without having to torture ourselves, precisely because it is the natural weight for us. In practice, it's quite hard.
(There's a blog post bubbling in my head about how Everything I Was Told About Health As A Child Was Entirely Wrong. Not just sort of wrong, but "everyone needs to eat three meals a day"-is-also-wrong levels of absolutely, positively everything I was told is wrong. The only thing I can think of that was true is that exercise is important, but even then, there was a radical overemphasis on aerobic exercise when I now believe the correct focus for most people is strength training.)
The first Google result on the term is pretty good: http://jamesclear.com/the-beginners-guide-to-intermittent-fa...
At its simplest, for men it means eating all your food for the day in a roughly eight-hour window, often noon to 8pm. (There is apparently some scientific thought that women may have significantly different needs; I really can't speak to that.) In practical terms, this translates to "skipping breakfast" and avoiding midnight snacks. This turns out not to be that difficult, but has definitely had an positive impact on me, so far. Discomfort-wise for me, I tend to get a bit of a rumbly tummy around 10am, but generally it subsides pretty quickly and even by 11am I can easily go for another couple of hours without even thinking about lunch if I get busy. It is far from constant hunger. (But I won't lie and say it's zero... just, negligible. Literally. It can easily be neglected and it will in fact go away.) I can also say that I'm hardly watching the clock in the evening and trying to judge whether it's the crack of 8pm yet or not... I often eat at noon-thirty or 1pm and then dinner at 6pm and am done thinking about food for the day, without any willpower expended. It just happens.
I say this mostly to point out to people that there is something to investigate that they may have misconceptions about, as I did. I will fully and up-front admit once again I am not in a position to extol its benefits particularly. (I like to do something like this for at least a couple of years before I do that.)
(But I will go slightly out on a limb and say that I would not be all that surprised to discover that "intermittent fasting" has somewhere between 80-120% of the benefit of the scientifically-studied high caloric-restriction diets, with much lower willpower and discomfort costs. It turns out that if you dig into those, we've really only studied "normal (modern) diet", "heavily calorically restricted", and sometimes a particularly unrealistic fasting schedule (see link), so if you're interested in a point in the middle of the two we've studied, you're sort of scientifically on your own. Hence the possibility I cite of 120%; currently it would fit the two data points we have just fine for it to turn out that "caloric restriction" isn't the optimum and is in fact overshooting.)