Re: Soluble versus Insoluble fiber calories

[Guest guest]

I dont know if you checked the reference in my post

last year on this topic that either Tony or Rodney

referred you to.. but if you didnt, here it is again.

+++++++++++++++++

the estimate is 1.5-2.5 cal/g. So lets say 2. As

most american get in around 15 grams of fiber, its

around 30 calories. If you hit the RDA or 25, its 50

calories. If you hit the higher recommendations of

30-40 ish, its still only 60-80. So, for most people

it doesnt contribute many calories.

http://darwin.nap.edu/books/0309085373/html/349.html

Contribution of Fiber to Energy

When a metabolizable carbohydrate is absorbed in the

small intestine, its energy value is 16.7 kJ/g (4

kcal/g); when fiber is anaerobically fermented by

colonic microflora in the large intestine, short-chain

fatty acids (e.g., butyrate, acetate, and propionate)

are produced and absorbed as an energy source. Once

absorbed into the colon cells, butyrate can be used as

an energy source by colonocytes (Roediger, 1982);

acetate and propionate travel through the portal vein

to the liver, where propionate is then utilized by the

liver. Acetate can be metabolized peripherally. A

small proportion of energy from fermented fiber is

used for bacterial growth and maintenance, and

bacteria are excreted in feces, which also contain

short-chain fatty acids (Cummings and Branch, 1986).

Differences in food composition, patterns of food

consumption, the administered dose of fiber, the

metabolic status of the individual (e.g., obese, lean,

malnourished), and the digestive capability of the

individual influence the digestible energy consumed

and the metabolizable energy available from various

dietary fibers. Because the process of fermentation is

anaerobic, less energy is recovered from fiber than

the 4 kcal/g that is recovered from carbohydrate.

While it is still unclear as to the energy yield of

fibers in humans, current data indicate that the yield

is in the range of 1.5 to 2.5 kcal/g (Livesey, 1990;

et al., 1998).

[Guest guest]

This reference does not appear to differentiate between soluble and

insoluble fiber. Many foods contain large amounts of insoluble fiber

(e.g. many vegetables, cocoa powder), while others contain a large

amount of soluble fiber (e.g. many grains). Is this study lumping

both types of fiber together with some average weighting? Or does

this study refer either to soluble or insoluble fiber specifically?

It is not clear to me.

Thanks,

-Dave

--- In , Jeff Novick <chefjeff40@...>

wrote:

>

> I dont know if you checked the reference in my post

> last year on this topic that either Tony or Rodney

> referred you to.. but if you didnt, here it is again.

>

> +++++++++++++++++

>

> the estimate is 1.5-2.5 cal/g. So lets say 2. As

> most american get in around 15 grams of fiber, its

> around 30 calories. If you hit the RDA or 25, its 50

> calories. If you hit the higher recommendations of

> 30-40 ish, its still only 60-80. So, for most people

> it doesnt contribute many calories.

>

> http://darwin.nap.edu/books/0309085373/html/349.html

>

> Contribution of Fiber to Energy

>

> When a metabolizable carbohydrate is absorbed in the

> small intestine, its energy value is 16.7 kJ/g (4

> kcal/g); when fiber is anaerobically fermented by

> colonic microflora in the large intestine, short-chain

> fatty acids (e.g., butyrate, acetate, and propionate)

> are produced and absorbed as an energy source. Once

> absorbed into the colon cells, butyrate can be used as

> an energy source by colonocytes (Roediger, 1982);

> acetate and propionate travel through the portal vein

> to the liver, where propionate is then utilized by the

> liver. Acetate can be metabolized peripherally. A

> small proportion of energy from fermented fiber is

> used for bacterial growth and maintenance, and

> bacteria are excreted in feces, which also contain

> short-chain fatty acids (Cummings and Branch, 1986).

> Differences in food composition, patterns of food

> consumption, the administered dose of fiber, the

> metabolic status of the individual (e.g., obese, lean,

> malnourished), and the digestive capability of the

> individual influence the digestible energy consumed

> and the metabolizable energy available from various

> dietary fibers. Because the process of fermentation is

> anaerobic, less energy is recovered from fiber than

> the 4 kcal/g that is recovered from carbohydrate.

> While it is still unclear as to the energy yield of

> fibers in humans, current data indicate that the yield

> is in the range of 1.5 to 2.5 kcal/g (Livesey, 1990;

> et al., 1998).

>

[Guest guest]

I also meant to state that your numbers (below) for total fiber

calories consumed appear to be on the low side for CRONies, at least

for me. According to the Cron-o-meter, I'm consuming 65-70 grams of

fiber per day on an 1800 calorie diet. Perhaps I consume far more

vegetables than most, but were talking significant fiber calories

here -- not something to ignore with respect to an accurate calorie

count.

--- In , Jeff Novick <chefjeff40@...>

wrote:

>

> I dont know if you checked the reference in my post

> last year on this topic that either Tony or Rodney

> referred you to.. but if you didnt, here it is again.

>

> +++++++++++++++++

>

> the estimate is 1.5-2.5 cal/g. So lets say 2. As

> most american get in around 15 grams of fiber, its

> around 30 calories. If you hit the RDA or 25, its 50

> calories. If you hit the higher recommendations of

> 30-40 ish, its still only 60-80. So, for most people

> it doesnt contribute many calories.

>

> http://darwin.nap.edu/books/0309085373/html/349.html

>

> Contribution of Fiber to Energy

>

> When a metabolizable carbohydrate is absorbed in the

> small intestine, its energy value is 16.7 kJ/g (4

> kcal/g); when fiber is anaerobically fermented by

> colonic microflora in the large intestine, short-chain

> fatty acids (e.g., butyrate, acetate, and propionate)

> are produced and absorbed as an energy source. Once

> absorbed into the colon cells, butyrate can be used as

> an energy source by colonocytes (Roediger, 1982);

> acetate and propionate travel through the portal vein

> to the liver, where propionate is then utilized by the

> liver. Acetate can be metabolized peripherally. A

> small proportion of energy from fermented fiber is

> used for bacterial growth and maintenance, and

> bacteria are excreted in feces, which also contain

> short-chain fatty acids (Cummings and Branch, 1986).

> Differences in food composition, patterns of food

> consumption, the administered dose of fiber, the

> metabolic status of the individual (e.g., obese, lean,

> malnourished), and the digestive capability of the

> individual influence the digestible energy consumed

> and the metabolizable energy available from various

> dietary fibers. Because the process of fermentation is

> anaerobic, less energy is recovered from fiber than

> the 4 kcal/g that is recovered from carbohydrate.

> While it is still unclear as to the energy yield of

> fibers in humans, current data indicate that the yield

> is in the range of 1.5 to 2.5 kcal/g (Livesey, 1990;

> et al., 1998).

>