Fiber blocks calories??

[bethtwenty4]

I read an article last night that said for every gram of fiber you eat will block 7 calories from being absorbed...SO...I ate 117g yesterday. Does that mean that I can subtract 819 calories from my total intake?? Also, does this have an effect on protein usage? (this wasn't addressed in the articles)

*I did an Internet search on this and two other sources reported the same thing*

Any thoughts?

[kfairhurst]

I read an article last night that said for every gram of fiber you eat will block 7 calories from being absorbed...SO...I ate 117g yesterday. Does that mean that I can subtract 819 calories from my total intake?? Also, does this have an effect on protein usage? (this wasn't addressed in the articles)

*I did an Internet search on this and two other sources reported the same thing*

Any thoughts?

No lol, not happening... Lots of people also think fiber is not absorbed and can be subtracted from your daily totals.

[Emma-Leigh]

scroll down the page a little -> big thread Fiber and Things (http://forum.bodybuilding.com/showthread.php?t=117183851).

[smbrown3706]

Sounds like quackery to me...

[Emma-Leigh]

It isn't. ;)

It is a well known fact that the digestibility / NET energy from foods is related to fiber content, especially non-digestible fiber.

YES - some fibers move on into the large intestine where they are broken into short-chain fatty acids by gut bacteria (which can be used), but some isn't digested. And this binds nutrients in the gut and decreases their absorption - not only micronutrients (calcium, iron, etc), but also protein and fat.

http://jn.nutrition.org/cgi/reprint/111/2/287.pdf
http://www.springerlink.com/content/n69x227l244m316q/
http://jn.nutrition.org/cgi/reprint/117/2/267.pdf

[bethtwenty4]

Thanks for the extra reading Emma! I eat a pretty high fiber diet (80g+). I don't eat much pre/post workout so hopefully it's not affecting my protein absorptiion!

I also thought it sounded a bit too good to be true...But I'll take it :)

[determined4000]

It isn't. ;)

It is a well known fact that the digestibility / NET energy from foods is related to fiber content, especially non-digestible fiber.

YES - some fibers move on into the large intestine where they are broken into short-chain fatty acids by gut bacteria (which can be used), but some isn't digested. And this binds nutrients in the gut and decreases their absorption - not only micronutrients (calcium, iron, etc), but also protein and fat.

http://jn.nutrition.org/cgi/reprint/111/2/287.pdf
http://www.springerlink.com/content/n69x227l244m316q/
http://jn.nutrition.org/cgi/reprint/117/2/267.pdf

I have always wondered about this.
Especially with vegetables.
Ex. If you take 1NLEA serving broccoli it is (http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2356/2)
50 calories
4.2g protein
10g carbs
5 calories from fat

Know as far as % go, that would yield 33% of calories from protein, yet nuritiondata.com shows 20%.
If you scroll down it is because there are only 10.2 calories absorbed from protein (2.5grams vs 4.2).
This is supported by the link you gave that says vegetables only 2.44 calories per gram, as opposed to whole protein sources 4.3cals/gram. Similarly, with fat you absorb the full 9calories per gram for meat and almost that with direct fat sources but only 8.37/gram for starches.

Does that mean when caclulating macros, you should take into account these differences?
Do you really absorb less protein and fat from starches and veggies than you think you are actually getting? Or are the calories just lost but the amino acids and fatty acids still present and absorbed?

[thegymbum]

If you're eating enogh fiber to cause nutrient malabsorption, you're going to cause malabsorption of more than just calories. The calories "blocked" by fiber are increibly minimal, you could save the same number of calories by taking something like one less bite of food. But anyway, too much fiber also causes micronutrient malabsorption- especially divalent cations such as calcium, magnesium, zinc, iron, etc. Stick with the recommended range.

[Emma-Leigh]

If you're eating enogh fiber to cause nutrient malabsorption, you're going to cause malabsorption of more than just calories. The calories "blocked" by fiber are increibly minimal, you could save the same number of calories by taking something like one less bite of food. But anyway, too much fiber also causes micronutrient malabsorption- especially divalent cations such as calcium, magnesium, zinc, iron, etc. Stick with the recommended range.
^^^ Recommended ranges for fiber (for america anyway) are well known to be inadequate in terms of overall health.

^ most research out suggests the micronutrient absorption issue isn't as significant as once thought. Especially when considered in light of a micronutrient rich/ nutrient rich (adequate) diet.

Lots of info/ links here: http://forum.bodybuilding.com/showthread.php?t=117183851
And a good read here: http://paleobioticslab.com/are-government-recommendations-for-daily-fibre-intake-too-low-an-evolutionary-perspective/

[GoldenGains]

I've heard some soluble fibers like psyllium husk forms like a gel in your stomach and can bind to other nutrients stopping them from being absorbed. I say go for insoluble like broccoli

[iLoLd]

maybe thats why broccoli is always promoted by pros

[doctapeppadoc]

It can slow odwn digestion but doesn't prevent nutrients from getting absorbed.. I'm pretty sure anyawy.

[TomBremner]

I've heard some soluble fibers like psyllium husk forms like a gel in your stomach and can bind to other nutrients stopping them from being absorbed. I say go for insoluble like broccoli

i could totaly believe this, ever mix it with water and let it sit for 10 minutes? imagine that over hours...

[Clubber]

I've heard that when looking at the carbs you've consumed in a day, to get "net carbs", dietary fiber is subtracted from total carbohydrates.

I don't think it blocks calories tho

[audipotential]

Thanks for the extra reading Emma! I eat a pretty high fiber diet (80g+).

I would be extremely careful with this. Its possible to get an intestinal blockage from fiber being too high.

[ALLUCANEATRIBS]

how on earth do you get 100g+ of fiber intake? I try to get around 15-20g & thats pretty difficult

[stevejuice]

It isn't. ;)

It is a well known fact that the digestibility / NET energy from foods is related to fiber content, especially non-digestible fiber.

YES - some fibers move on into the large intestine where they are broken into short-chain fatty acids by gut bacteria (which can be used), but some isn't digested. And this binds nutrients in the gut and decreases their absorption - not only micronutrients (calcium, iron, etc), but also protein and fat.

http://jn.nutrition.org/cgi/reprint/111/2/287.pdf
http://www.springerlink.com/content/n69x227l244m316q/
http://jn.nutrition.org/cgi/reprint/117/2/267.pdf


Yes. Most fiber passes right through you. It also binds to bile acids and brings some of it along too, which is why fiber is good to help lower cholesterol. (Bile acids are made from cholesterol, so the more bile acids excreted, the more cholesterol will go towards making new bile acids.)