So, my gf has started to follow intermittent fasting. Which is a kind of diet (although she states it isn’t a diet) where you only eat during 8 hours and fast during 16 hours. She isn’t overweight, and in fact is in great shape, since she’s exercising a lot, but she has some belly fat she would want to go away. Basically, the idea is that after 12 hours or so of fasting your body starts to lack sugars and begins to use fat.
So, she would want to know what is the collective wisdom on this generally well informed board about intermittent fasting. Thanks in advance.
Just jumping in to say I have a colleague that adheres to this method of “Fasting”. He is mid 20’s and in very good shape. It makes him happy so why would I care?
I don’t get it, but if it is the way you wanna eat so be it! I typically only eat once a day, I run a Pizzeria so I do graze a bit through the day but not much.
There are many threads about this already. I’ll just say that I love intermittent fasting. It helps me manage my appetite in a way that nothing else does. I just eat a tiny lunch of a few hundred calories and then whatever I want for dinner within reason at a reasonable time and fast until the next lunch. It’s pretty easy really.
Best case scenario is that it is just like reducing calories at normal meal times plus some marginal health benefits of fasting.
Worst case scenario is that it is marginally more catabolic of muscle compared to normal meal times without any health benefits.
I think the worst case scenario is more likely (though we don’t have enough evidence to say). So I wouldn’t recommend it unless diet compliance is a proven problem for the person. And if they do prefer IF, then they should really be resistance training to preserve muscle.
So, people typically go something like 12 hours between meals (dinner at 6 PM, breakfast at 6 AM, or something similar) and people are extending that from 12 to 16 hours and calling it a "fast?
:rolleyes:
Why not extend it to 18 hours and call it a hunger strike?
I have been doing it for a year and it’s been great. Even before any weight loss benefits, I immediately found myself with increased energy during my waking hours.
As I understand it there are hormonal (?) effects that are operational while you sleep, which suppress appetite. So you should really only count continuous waking hours as ‘fasting’ hours. That would put ‘intermittent fasting’ about half way between normal eating (go about 4 waking hours between eating) and something like the Ramadan fast (go about 12 waking hours between eating)
I’ve been doing the 16/8 (more often 18/6}.since October. I started doing it to help control blood glucose during a time my doctor had me off metformin for a test or two. The results were better glucose control than the drugs were giving me. I’ve lost 7 or so pounds since then (unintentionally) and generally have more energy and less desire for naps during the day.
I certainly don’t think it’s for everyone but it works well for me.
I do 5:2. (600 calories 2 days a week, “normal” portions the other 5 days). I find it a better maintenance diet than weight lost diet (you REALLY have to strictly stick to normal portions to lose weight, a lot of people make the mistake of just eating whatever they want), but I’ve been doing it a long time (2 years or so), it’s easier to stick to than any other think I’ve tried, and have had no ill effects so far that I know of.
My girlfriend started that, too. She’s been at it for about a year, and she’s lost quite a bit of weight. She’s always showing off some article of clothing that no longer fits because it’s too loose.
The first month or so was hard on her. I imagine that it takes a while to get used to. Now, she opens her window around 4, when she has a snack or a treat. She eats a big supper around 6, followed by more snacks in the late evening. Candy, usually.
She passed out from low blood sugar a few years ago, but–while I’m always harping on her to carry an emergency snack–she hasn’t had any episodes during her fake fasting (as I call it).
With a young kid at home I routinely finish dinner before 7pm, and I often don’t get breakfast until 9:30-10:00 the following day. That puts me at 15/9 without knowing this kind of thing was a…thing. Curse you for making me aware, because now I’m going to have the urge to binge on late night snacks!
If I (or her kids) want to be sweet, breakfast in bed is out. (I’m sure she would eat it, just as I’m sure she would appreciate the gesture, but it’d wreck her day.)
Coffee is fine for her to have at any time of the day, but I can’t serve up her favorite wine or a beer any earlier than 4 PM, not even on weekends. Or, if I do, her window opens early, which means it closes early, and she has to give up munching on chocolate and chips while we watch TV later that night.
Lunchtime for me is lonely. I have to eat by myself (sniffle). “Honey, I’m making a sandwich, would you like one, too?” is no longer uttered in our house. Only took me about six months to stop asking. Going out for lunch together also never happens.
I started on January 1 doing 16/8. I eat only between the hours of noon and 8 pm.
It’s not at all difficult for me in the morning since I rarely eat breakfast anyway. And it eliminates my night eating, which has long been a problem for me. I’ve dropped around 10 lbs. so far.
mmm
There are actually fairly few controlled human studies on “time-restricted feeding” (TRF) and those that there are generally are fairly small n. Moreover the studies are early-TRF, for example like this 2018 one in which prediabetic men were randomized into either a 12 hr period or a 6 hour period of feeding the latter with “dinner” done before 3 pm (and then crossed over). Total n was 8.
Still such is the data we have, but there is of note from the review portion of the article that the early part of the TRF is of importance.
Let me highlight one line of that:
"restricting food intake to the late afternoon or evening (after 16:00 hr.; “late TRF” [lTRF]) either produced mostly null results or worsened postprandial glucose levels, β cell responsiveness, blood pressure, and lipid levels "
Their study even with the small n ended up showing some pretty significant results of early TRF on metabolic measures even without any, i.e. independent of, weight loss. Eating most of your calories fairly early and not having many late calories may be of real benefit … but I’d make a wild assed guess that a good portion of those doing TRF because they’ve heard about it in some article or on the internet are restricting themselves by skipping breakfast and still having an evening dinner as the biggest meal of the day. And the evidence we have is that doing that may be of more harm than good.
Mind you going from eating lots after 8 pm to stopping by then, like MMM did, is still an improvement! And even if the late timing is a detriment if the time restriction causes calorie reduction then the net will likely be a positive.
Real life is that dinner is, for many of us, a family social time. The benefits of sitting down to eat with my wife, even as my fourth child is a senior in High School and rarely eats with us anymore, are so big that if that means I eat at 8 pm because one or the other of us is often working late, well it’s worth the metabolic hit. But I do believe that disciplining myself to eat that as a small meal and eating more of my day’s calories earlier would be a good idea. Even going outside a 12 hour window to do so.
Be careful with this if you have any history of disordered eating patterns. The hunger can trigger binge behavior, and for me it made me hard lapse into full anorexia which I hadn’t experienced in years.
