5

votes

IF: Still Unclear on the Concept!?

Answered on September 12, 2014
Created June 16, 2012 at 2:54 AM

So, I'm reading this Abs Diet cookbook (I know, not paleo at all!), and come across this:

"Think about it: You???ve been fasting for the past 8 to 10 hours since you ate last night???s snack. While you were sleeping, your body???s metabolism slowed down. By sacrificing breakfast when you wake up, you???re operating on reserve fuel. Your body doesn???t know there are eggs in the fridge; it thinks food is scarce so it throttles down your metabolism even further to protect you from starvation."

If I am "fat adapted", this is not an issue, right? I'm not starving myself if I IF, or is it because I'm starving myself that IFing works? What IS happening with my metabolism when I IF? Still using my fat for fuel just as if I was eating paleo-as-usual ... right? Or does it slow down?

19ff515e8ec02d95e8f2cf68c3ec1373

(1207)

on August 23, 2012
at 11:20 PM

Unfortunately the study is flawed. Compared significantly overweight men to only slightly over weight women. Unfortunately, no real conclusion can be drawn from it. Pity, I want to know too.

2336245491a87ee15d4fb8f8f8283909

(1173)

on July 02, 2012
at 03:03 AM

I do it every day...I have a 6 hour eating window and fast for 18. I just make sure I get adequate calories when I eat.

Dc6407193ba441d1438f6f0c06af872b

(4400)

on June 16, 2012
at 02:22 PM

+1 for science! The author apparently didn't know and was guessing. And has been pointed out, it also intuitively doesn't hold water that evolution would have produced a hunter-gather who is hampered in the ability to hunt and gather because they had to skip breakfast.

34b560c8b9ce660d7839fb7e29d7be89

on June 16, 2012
at 09:40 AM

@Julie-This addresses your questions about as well as possible. http://www.paleoforwomen.com/shattering-the-myth-of-fasting-for-women-a-review-of-female-specific-responses-to-fasting-in-the-literature/

5f3e1f803d7a9b8704bb11cda26bcf9a

(658)

on June 16, 2012
at 04:10 AM

Can anyone tell me if these studies included women and what stage of their lives? It would be helpful because of the differences in harmones for women as apposed to men and differences at different stages of life.

Medium avatar

(211)

on June 16, 2012
at 03:37 AM

How often do you IF within the month, and for how long, if you don't mind me asking?

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8 Answers

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5
35b2cb4d450e5288895c255dfdfff35d

(5828)

on June 16, 2012
at 03:34 AM

No, you're not starving yourself if you do IF.

In terms of what happens when you IF, it's not clear what exactly is going on while you're not eating. I think the author of the Abs Diet cookbook is a bit naive to think that skipping breakfast puts you into starvation mode. Paleo people didn't have the luxury of feeding themselves regularly and continuously. Some of the fat burning gurus are into eating small meals frequently throughout the day. That's what this author's position might be. But, frequency of eating is one of those controversial topics. People can burn fat eating five small meals per day and they can burn fat eating three regular-size meals per day.

The best guide I've seen to IF is here. I like this free online ebook because it is based on the author's personal experience, it is well written, easy to understand, and most importantly, it's not full of the hype that most articles on IF are full of.

The more you read about IF the more you'll realize that your mileage will vary. It's not the holy grail of fat loss for everybody although it works really well for some people. IF worked ok for me when I used it a while back but I like to eat so I can't personally get too excited about it.

To speak to your question of what happens to your metabolism, here's a list of benefits (from the ebook) to whet your appetite:


The proposed benefits of IF in animals and humans read like a laundry list of ???look better,??? ???feel better,??? ???live longer??? physiological changes. These include:

REDUCED

  • blood lipids (including decreased triglycerides and LDL cholesterol)
  • blood pressure (perhaps through changes in sympathetic/parasympathetic activity)
  • markers of inflammation (including CRP, IL-6, TNF, BDNF, and more)
  • oxidative stress (using markers of protein, lipid, and DNA damage)
  • risk of cancer (through a host of proposed mechanisms; we???ll save them for another review)

INCREASED

  • cellular turnover and repair (called autophagocytosis)
  • fat burning (increase in fatty acid oxidation later in the fast)
  • growth hormone release later in the fast (hormonally mediated)
  • metabolic rate later in the fast (stimulated by epinephrine and norepinephrine release)

IMPROVED

  • appetite control (perhaps through changes in PPY and ghrelin)
  • blood sugar control (by lowering blood glucose and increasing insulin sensitivity)
  • cardiovascular function (by offering protection against ischemic injury to the heart)
  • effectiveness of chemotherapy (by allowing for higher doses more frequently)
  • neurogenesis and neuronal plasticity (by offering protection against neurotoxins)

34b560c8b9ce660d7839fb7e29d7be89

on June 16, 2012
at 09:40 AM

@Julie-This addresses your questions about as well as possible. http://www.paleoforwomen.com/shattering-the-myth-of-fasting-for-women-a-review-of-female-specific-responses-to-fasting-in-the-literature/

5f3e1f803d7a9b8704bb11cda26bcf9a

(658)

on June 16, 2012
at 04:10 AM

Can anyone tell me if these studies included women and what stage of their lives? It would be helpful because of the differences in harmones for women as apposed to men and differences at different stages of life.

19ff515e8ec02d95e8f2cf68c3ec1373

(1207)

on August 23, 2012
at 11:20 PM

Unfortunately the study is flawed. Compared significantly overweight men to only slightly over weight women. Unfortunately, no real conclusion can be drawn from it. Pity, I want to know too.

2
64433a05384cd9717c1aa6bf7e98b661

(15236)

on June 16, 2012
at 05:53 AM

Your metabolism doesn't begin to slow down until roughly 60 hours of fasting

http://www.ncbi.nlm.nih.gov/pubmed/3661473

And in contrast, metabolic rates actually increase between 36-48 hours

http://www.ncbi.nlm.nih.gov/pubmed/2405717

http://www.ncbi.nlm.nih.gov/pubmed/10837292

Dc6407193ba441d1438f6f0c06af872b

(4400)

on June 16, 2012
at 02:22 PM

+1 for science! The author apparently didn't know and was guessing. And has been pointed out, it also intuitively doesn't hold water that evolution would have produced a hunter-gather who is hampered in the ability to hunt and gather because they had to skip breakfast.

0
Dbb6872f139877fe1a94aeb471baa7d1

on August 23, 2012
at 10:19 PM

I've asked several people this question because I feel sick if I eat early in the morning. I'm usually up around 5:30am, but I don't eat until 9 or 10, and occasionally I don't eat until noon or so. I feel better when I follow my body's desires in this way, and everyone I've ever asked who follows Primal/Paleo has said it's no biggie.

Just thinking logically, it makes no sense for your body to panic after a measly 12 hours without food. Wouldn't that be a lot of needless stress? Ancient man didn't have eggs in the fridge -- many times, they would follow an animal for a day or more before being able to kill it, and they ate little when on the track like this.

In anecdata, I have a variety of digestive issues, and my guts function better when they get that rest. I eat lunch and dinner, most days, and occasionally some nosh at home.

0
D3361edfe7f3b6f61ece98817e9e0248

on August 23, 2012
at 08:55 PM

go to w w w.lengains.c o m, no one on here will be be able to explain the concept better than Martin Berkhan

0
B7e1ad6bb9ab814b8e90bdad4a472d5e

on August 23, 2012
at 07:30 PM

Will be the nice guy here:D you need to go to google "top 10 fasting myths debunked" by Martin Berkhan. Happy reading :D

then read all rest of his articles they are worth their weight in gold

0
B7e1ad6bb9ab814b8e90bdad4a472d5e

on June 16, 2012
at 08:23 AM

starvation mode only kicks in after 96 hours. And the only way to get a higher metabolism is to have more muscle mass. so whenever you go to the gym and you see people doing thousand crunches will know they'll never get a six pack. should be doing big four bench weighted pull-ups squats and dead lifts.

0
2336245491a87ee15d4fb8f8f8283909

(1173)

on June 16, 2012
at 03:16 AM

Your metabolism doesn't react that fast. Missing a meal or 2 doesn't = starvation. This is my second cycle/first month of intermittent fasting and pretty much ripped by now. If it is effecting my metabolism at all, I'm not seeing it. I especially like training on empty.

Medium avatar

(211)

on June 16, 2012
at 03:37 AM

How often do you IF within the month, and for how long, if you don't mind me asking?

2336245491a87ee15d4fb8f8f8283909

(1173)

on July 02, 2012
at 03:03 AM

I do it every day...I have a 6 hour eating window and fast for 18. I just make sure I get adequate calories when I eat.

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