Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEG
 

nature.com: Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage. IF, a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction.

http://www.nature.com/cr/journal/va...otcallback=true

Abstract
Intermittent fasting (IF), a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction. However, our understanding of the underlying mechanisms of IF-mediated metabolic benefits is limited. Here we show that isocaloric IF improves metabolic homeostasis against diet-induced obesity and metabolic dysfunction primarily through adipose thermogenesis in mice. IF-induced metabolic benefits require fasting-mediated increases of vascular endothelial growth factor (VEGF) expression in white adipose tissue (WAT). Furthermore, periodic adipose-VEGF overexpression could recapitulate the metabolic improvement of IF in non-fasted animals. Importantly, fasting and adipose-VEGF induce alternative activation of adipose macrophage, which is critical for thermogenesis. Human adipose gene analysis further revealed a positive correlation of adipose VEGF-M2 macrophage-WAT browning axis. The present study uncovers the molecular mechanism of IF-mediated metabolic benefit and suggests that isocaloric IF can be a preventive and therapeutic approach against obesity and metabolic disorders.

There are a few variants of what is grouped as “intermittent fasting”. I have been on time restricted feeding for a few months with good success. I was using a 14/10 fasting/feeding window but have recently upped it to 17/7 with significant results.

I did one meal a day for a whole week and it felt good. This was part of my therapeutic niacin dosages, which did wonders for my metabolism.

IF Uncertainty
 

Background:
I have been following a 16/8 IF protocol for about 2 month now. I'm calling it 16/8, but sometimes stretch it to 17/7 or even 18/6. While I do not mean this in a negative way, I have not seen any benefits from it. I was at my goal weight when I started, but still have some belly fat, and feel like I could afford to lose another 10 lbs. I have seen normal fluctuation of a couple lbs either way over the 2 months, but no real change. To be fair, this is not scientific, as I have also made some other changes in that period. For example, I stopped recording every detail of what I eat, but still stick to a low carb diet. I stopped tracking weather I was in ketosis, but I was not in ketosis for most of my weight loss. I added some basic exercise, push ups, burpees, lung, but nothing high intensity. While not weighing and recording calories, I know they are lower, as the 10am to 6pm feeding window keeps me from snacking in the evening, and eliminates the need for between meal snacks.
Uncertainty:
IF is supposed to have a lot of benefits, such as insulin sensitivity, autophagy, increased hgh, etc. I have no reason to doubt that, but I have no realistic way to measure or know how those effect me.
Leangaines or 16/8 seems to be a popular IF protocol, but most of the studies I have looked at use alternate day fasting. The study referenced in the original post states they developed a 2 day eating with 1 day fasting protocol because to lessen the difference in caloric intake between the test subjects. That doesn't seem to be how most people IF, and it is not clear to me how much the time frame or protocol affects the results.
There is a wide range of opinion on what is allowed during the fast. For example, I recently saw an interview where it was stated anything but water will cause the body to expect food, and make changes that affect the fast. I have seen other opinions, Dr. Jason Fung for example, who say cream in coffee and bone broth is Ok. Others say you can have certain fats during the fast. I have not seen any research that tests how these differing approaches actually affect the benefits like autophagy and hgh. Rather these all seem to be just opinion.

Even with these uncertainties, I do plan to continue to follow the IF or time restricted eating protocol for the near future. If nothing else, I like that it has helped me to stop the evening snacks. I have found that to stay in ketosis, I need to pretty much be on Atkins 72 induction, which he called biologically zero carbs. I may try that again with the IF, and see how that goes for the next 2 months. In the meantime, I am interested in how other people see or consider these IF uncertainties.

My experience with IF was not magical, except perhaps some extended fasts where there seemed to be repeatable positive psychological spin-off (I thinnk it's extremely hard to feel autophagy happening in my body ;) ), it was practical:

- I ate one meal a day heavy in FAT
- I was less hungry in off eating hours, I spent less time thinking about food.
- I would assume I was in calorie deficit state as far as what went into my mouth but it came from somewhere...
- and that was my body I guess

Now as a leaner person I'm experimenting more with it for how it fits into a my lifestyle. I like not having to spend more time in the kitchen, shopping and doing dishes. IF helps with that I'm not sure it's a great weight loss tool if you're near your normal weight.

I've heard many times "Eat when you're hungry, Stop when you're full"

I'm finding a more practical way for me to do self talk like this is:

"Don't eat if you are not hungry" I've spent many years eating just because it's something to do with my mouth. Now I have all you all to yell at ;)

Intermittent Thud (IT)

BTW, Nice write up and observertions/questions dcc0455 - thank you for that!

Yesterday was a travel day for me, so I ate breakfast at 8 and didn't eat again until 4, and wow was I hungry. And wow did my meal taste good :)

Hunger is the best sauce :)

Coffee might affect a fast, but that's not the same as saying that it will be worse than water fasting. Whether coffee makes things worse or better is so little studied at this point that personal preference might be the best way to go.

The leaner you get, the more tricks you have to use to get any leaner.

When it comes to weight loss/maintenance, I find an eating window more useful than every other day fasting. Maybe because I've only used it when I wasn't all that far from goal. Studies show people eating more on feeding days, but not enough to make up for fasting days--my appetite does expand on the feeding days enough to make up for the fasting days, but moreso the leaner I am.

Yes, I am questioning the ongoing weight loss stage vs the maintenance stage using IF. Right now, I'm still losing on OMAD, but when I reach goal (or close to it) will I need to maintain the same regimen? I guess I will find out. My family says that this way of eating is not sustainable, in that as soon as I go back to eating more than OMAD, all the weight lost will return? Not on my watch!

I have been doing 19/5 for almost 4 years and been maintaining for over 3. I don't know what would happen if I went back to 3 meals a day and have no intention of finding out. Just like the maintainers on this site are not planning to go back to SAD.

Yessssssssss!
 

I have got back on the wagon after losing 60 pounds, then my dad passed and I went back up. I am now back on the LCHF and I have added in 18/6 with 2 meals a day. I feel so great. I sleep well, have tons of energy, and I do not feel bloated at all. I have been sticking to the window and eating clean. The weight is coming off slow, but it's really only been 3 good weeks. haha lol I can't wait to see 3 and 6 month mark. I am also walking a ton. I love the fasting!

I drink a lot of coffee during my fasting window. I'm not saying I couldn't quit but until I see something more than opinion, I'm keeping it. I haven't tried, but it seems to me alternate day fasting would be a lot harder than 16/8. It was just routine for me after the first week.

Fabulous! I don't plan to go back to the old way of eating. My point is that once you have made goal there are not as many fat cells WAT to burn while fasting. Right? Where do the extra calories come from? Then we are back to calorie restriction vs fasting. I will NOT calorie restrict!

For me, fasting has restricted calories, but I have the same question, especially if you want to be in ketosis. I suppose one option is to adjust macros, e.g. increase fat.