Fasting and Hormones
I asked this the other day but did not get much in the way of answering my question, so I am going to try this again. When it comes to fasting, what affect does it have on your hormones? I have read that when your body senses a food shortage it tends to store and hold onto body fat. So, if I fast this is what is happening, no? Does fasting promote fat storage or fat release? How does fasting not mess with your hormones to the point of fat storage?
What you are asking about is the reverse T3 hormone that goes up when your body senses "famine."
Some on that here- Why Does a Starvation Diet Slow Metabolism?
Here's something else I put together in May when I was looking at IF vs simple calorie restriction- What’s the Deal with Intermittent Fasting (IF) vs Calorie Restriction?
After this was done, the leptin topic took off. Leptin resistance is also measured by checking rT3- What’s the Deal with Intermittent Fasting (IF) vs Leptin Resistance?
You can have high rT3 if you just stop eating (famine) or if your body THINKS it stopped eating (leptin resistance). You don't want high rT3. You don't want to IF if you have, or will get high rT3. How do you know how long an IF is too long to kick in famine mode? Good luck with that. Maybe 24-48 hrs, maybe not. You can't trust what an IF site says about this because they don't want to hear it. Martin at leangains laughs at it, but his IF is less than 24 hrs, and he doesn't know this stuff anyway.
If you have a lot of weight to lose, think about leptin resistance first before the IF routine unless you like being a hormone wreck. If you are at or close to your goal. Do your IF, but I would stay with less than 24 hrs.
I'll give this author credit for running this at the end...
Originally Posted by Sue
"*Disclaimer: IF is meant for healthy individuals and may not be suitable for everyone. If you have any concerns you should talk with your physician before attempting. Use at your own risk."
They didn't explain this or even mention rT3, but it's better than nothing! I doubt most drs would know or understand the rT3 thing either.
The decrease in T3 and increase in rT3 is normal in starvation.
Todd Becker had some interesting comments to your thread on livinlowcarbdiscussion:
DFH attempt at a "fair and balanced" writeup on IF
"But, please, let's stop creating fake monsters to destroy, and focus on providing practical and useful advice. Nobody is claiming IF is a panacea that works for everyone under all possible circumstances. The evidence I've seen is that fasts of 12-24 hours, alternating with balanced refeeds, can have significant benefits with minimal risks, for most people. And you have yet to cite a single study suggesting ANY risks, even for elevated rT3 or other markers of hypothyroidism, for fasts of 24 hours or less, alternated with balanced refeeds."
The one thing that upsets me about the casual association being made between IF and starvation and the assumption that IF causes the same hormonal responses as starvation is that the whole context of one's diet isn't being considered. You can use IF without dieting and you don't get the hormonal responses that occur when you diet.
Starvation is starvation. It can happen if you are eating 6 mini meals a day, 3 meals a days in the traditional breakfast lunch and dinner pattern, or if you are doing a leangains style 16/8 IF. Starvation is about restricted nutrition continually over a period of time.
If your following IF (both the Eat Stop Eat method and/or the Leangains approach) the way you are supposed to, then it will not create hormonal problems any worse than any other calorie reduced/restricted diet will.
With leangains, you are supposed to fast for 14-16 hrs. On non training days, you eat 20% below maintenance calories. If you are going for fat loss that means 4-5 days a week you are eating in a deficit. The other 2-3 days, your training days, you are supposed to eat at a 20% SURPLUS - as in above maintenance. If you are doing this, *properly* then your hormones are not any worse off than they would be with a regular diet.
Same with Eat Stop Eat. You are only supposed to do a 24 hr fast 1-2 times a week (if I'm remembering correctly). Those are your deficit days. The days you aren't fasting, you are supposed to eat normally, not starve yourself some more.
Dieting is considered self starvation no matter what eating pattern is being used for it. Your hormones are going to go a little wacky regardless of the eating pattern. That's why you need to make sure you take it slow and take proper diet breaks or refeeds whether you are eating 6 mini meals from 8am to 6pm or eating 3 large meals between 12pm and 8pm or skipping 1 whole day of eating.
Starvation in the scientific studies refers to no food not calorie restriction.
Looked at Brad Pilons Eat Stop Eat and he doesn't mention T3 or rt3 as far as I can see. It would be interesting to see if he wrote anything about it. I definitely want to know more. I think there are quite a few studies on thyroid and appetite regulation.
I remember Becker whining on that site, but I don't recall him saying a damn thing when there was a thread about someone doing a full week-long fast! That is what sparked my attention, not short IFs.
Originally Posted by Sue
I'm not going to cite studies or get into "my link is better than yours" with him or anyone. I'm interested in discussing the topic logically, based on the best info we can get. Studies don't replace using your brain, they just support theories.
I don't see problems with 12-24 hr fasts either, for most people. But I'm not the one going around waving the IF flag without telling anyone what that really means and who it's for. We are STILL seeing people who have no business at all doing this read a few things and just dive in, and start asking how to get to 48 hrs or whatever-or people that are hormone wrecks tying to use it to get sorted out. (See leptin topics for some common sense on that.)
And yes, there are still people who are saying IF is for 100% of people. I saw that comment on here about a week ago.
Even though the IF folks are stirred up, you have to admit I made them stop and learn something!
Try not to get too bogged down in studies. What do YOU know about how this stuff works, and where does that take you? Use studies to support what you think, but don't use them to replace using your brain. You can find studies that say anything you want. They are often wrong or not really focused on what you think they are. I used to do studies myself. I know how it works.
Originally Posted by Sue
Agree! IF is not for everyone. It's like any other dieting trend though - people see it can bring fantastic results and they want to jump on the band wagon but they don't read up on it or they don't do it properly.
Originally Posted by DFH
There are people who force themselves to manage through the 16 hr fast, then force themselves to eat enough to manage the calorie intake they need/want. I've actually participated in a conversation wherein one individual was advising another individual how to stretch her stomach all in the name of doing IF(and if the stomach stretching didn't work, the advice was to consume liquid calories which is not at all promoted in the leangains style of IF). It's frustrating to read/see.
Of course a study wouldn't refer to dieting/calorie restriction as starvation - it puts a negative vibe on dieting. But dieting is a sort of starvation. How can it not be when you are limiting the amount of food your body requires at it's current weight? It might not be as severe as straight up no food, but it's still deprivation and over time your body does respond to dieting in a similar way that it would respond to starvation.
Originally Posted by Sue
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