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Created page with "A salad is a great way of getting fiber. Fiber is an essential part of a healthy diet, and is frequently misunderstood. Fiber does far mor..."
[[File:Salad.jpg|right|thumb|400px|A salad is a great way of getting fiber.]]
Fiber is an essential part of a healthy diet, and is frequently misunderstood. Fiber does far more than prevent constipation, helping with weight loss and overall health. Fiber is broadly defined as edible food that cannot be digested in the small intestine, and while some fiber is completely indigestible, other types can be partly digested further down the digestive tract.
=Weight Loss and Fiber=
One of the key benefits of fiber is to help with weight loss and weight control. Fiber can help with weight loss in many ways:
* Fiber can slow the emptying of the stomach, and delay the absorption of nutrients in the small intestine. This produces a feeling of fullness for longer<ref name="Sepple-1989"/> and fiber (30g/day) reduces hunger from low calorie diets<ref name="Astrup-1990"/>.
* Higher fiber intake is linked to long term weight control<ref name="Du-2010"/><ref name="Appleby-1998"/><ref name="Miller-1994"/><ref name="Davis-2006"/>.
* Fiber displaces the more energy dense components of food<ref name="Holt-1992"/> and can reduce the absorption of fat and protein<ref name="Livesey-1990"/>.
* Calories from fiber that is fermented varies between 1.5 and 2.5 Calories/gram<ref name="Smith-1998"/><ref name="Livesey-1990"/>.
* Fiber reduces the [[Glycemic Index]] of foods, which may be why fiber reduces subsequent hunger<ref name="Holt-1992"/><ref name="Bourdon-1999"/><ref name="Leathwood-1988"/>.
* Fiber reduces the energy that is absorbed from other (non-fiber) food<ref name="Heaton-1973"/>.
=Other Health Benefits=
There are a number of other health benefits from increased fiber intake.
* Some fiber is fermented in the colon by bacteria. This fermentation produces carbon dioxide, methane, hydrogen, and short-chain fatty acids. These short chain fatty acids are the preferred fuel for the cells in the colon<ref name="Roediger-1982"/> and if they are lacking they may cause [http://en.wikipedia.org/wiki/Ulcerative_colitis Ulcerative colitis]<ref name="Roediger-1993"/><ref name="Roediger-1980"/> and the colon cells to self-digest<ref name="Donohoe-2011"/>.
* Some, but not all, types of fiber will reduce constipation. For instance, Guar Gum is highly fermentable and does not change stool consistency<ref name="Slavin-1987"/>.
* Some types of fiber can normalize cholesterol levels<ref name="USDAFiber"/>.
* Cereal fiber provides substantial protection from Coronary Heart Disease<ref name="Bolton-Smith-1992"/><ref name="Humble-"/><ref name="Wolk-1999"/>. (There is little evidence for other types of fiber<ref name="USDAFiber"/>.)
* Fiber may provide protection against colorectal cancer, though the evidence is not conclusive<ref name="Bingham-2003"/><ref name="Park-2005"/>. In addition, fiber may protect against breast cancer<ref name="Dong-2011"/>.
=Increasing Your Fiber Intake=
Rapidly increasing your fiber intake can cause digestive pain, bloating and flatulence. These problems can be minimized or avoided by increasing your fiber intake gradually. It is also important to increase your fluid intake along with your fiber intake, as fiber will absorb several times its weight in water.
=Fiber classifications=
There are several ways of classifying fiber<ref name="FiberPauling"/>:
* '''Soluble and insoluble.''' A soluble fiber will disperse in water, where and insoluble fiber will not. At one time it was thought that this distinction would predict the physiological effects of the fiber, but this does not appear to be the case. However, the terms soluble and insoluble still widely used.
* '''Viscous and non-viscous.''' Some fibers form a thick, viscous gel tends to slow digestion and reduce cholesterol levels.
* '''Fermentable and non-fermentable.''' While the fiber cannot be digested directly by humans, it can be fermented by bacteria that naturally live in the colon.
Food packaging will only divide up fiber into soluble and insoluble, so it's important to understand the limitations of that categorization.
=Sources of Fiber=
Many good sources of fiber are also generally considered healthy foods, and there is a sample list below. In addition, it's worth noting that when pasta or rice is cooked and then left to go cold, some of the carbohydrate changes to form 'resistant starch', a form of fiber. A cup of cold pasta for instance, contains about 1.9 grams of resistant starch<ref name="NDWheat"/>.
==Legumes (beans)==
[[File:Beans.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Split peas, cooked||1 cup||16.3
|-
|Lentils, cooked||1 cup||15.6
|-
|Black beans, cooked||1 cup||15.0
|-
|Kidney beans, canned||1 cup||13.6
|-
|Lima beans, cooked||1 cup||13.2
|-
|Refried beans, canned||1 cup||12.2
|-
|Baked beans||1 cup||10.4
|-
|}
==Grains==
[[File:Pasta.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Spaghetti, whole-wheat, cooked||1 cup||6.2
|-
|Barley, pearled, cooked||1 cup||6.0
|-
|Bran flakes||3/4 cup||5.3
|-
|Oatmeal, quick, regular or instant, cooked||1 cup||4.0
|-
|Popcorn, air-popped||3 cups||3.5
|-
|Brown rice, cooked||1 cup||3.5
|-
|}
==Vegetables==
[[File:SaladVeg.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Artichoke hearts, cooked||1 cup||14.4
|-
|Peas, cooked||1 cup||8.8
|-
|Broccoli, boiled||1 cup||5.1
|-
|Sweet corn, cooked||1 cup||4.2
|-
|Brussels sprouts, cooked||1 cup||4.1
|-
|Potato, with skin, baked||1 medium||2.9
|-
|Tomato paste||1/4 cup||2.7
|-
|Carrot, raw||1 medium||1.7
|-
|}
==Fruits==
[[File:FruitPears.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Prunes, uncooked||1 cup, pitted||12.4
|-
|Pear, with skin||1 medium||5.5
|-
|Apple, with skin||1 medium||4.4
|-
|Strawberries (halves)||1 1/4 cup||3.8
|-
|Banana||1 medium||3.1
|-
|Orange||1 medium||3.1
|-
|}
==Nuts==
[[File:Nuts.jpg|right|thumb|200px]]
{| class="wikitable"
!'''Nuts'''!!'''Amount'''!!''''''Fiber (grams)''''''
|-
|Almonds||1 ounce (23 kernels)||3.5
|-
|Pistachio nuts||1 ounce (49 kernels)||2.9
|-
|Pecans||1 ounce (19 halves)||2.7
|-
|Peanuts||1 ounce||2.4
|-
|}
=Fiber Supplements=
While it's best to eat a wholesome diet which will be naturally high in fiber, sometimes it's useful to supplement your fiber intake. I use [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=Fiber&url=http%3A%2F%2Fwww.amazon.com%2FMetamucil-Smooth-Texture-Orange-114-Dose%2Fdp%2FB0013I1H9G Metamucil Sugar Free Powder] on a regular basis and it's helped with my weight control. I occasionally use [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=FiberClear&url=http%3A%2F%2Fwww.amazon.com%2FMetamucil-Natural-Clear-Mixing-Powder-Servings%2Fdp%2FB001EP3IEA Metamucil Clear] which uses a different type of fiber that has no texture or flavor. In both cases I mix the Metamucil and wait for at least 10 minutes, shaking or stirring periodically. If you drink it without waiting the regular Metamucil can be a little gritty, and after a few minutes both varieties will thicken up the drink.
=Flatulence=
Flatulence (gas) is a constant source of both humor and embarrassment. Unfortunately, this embarrassment causes people to avoid high fiber foods, even when they understand the benefits. The major components of intestinal gas are nitrogen, hydrogen, carbon dioxide and methane, all of which are odorless. The actual odor comes from tiny amounts of compounds such as ammonia, hydrogen sulfide, other sulfur compounds, short chain fatty acids, etc. Even though only trace amounts are produced, the human nose can detect them in concentrations as low as 1 part in 100 million<ref name="Bolin-1998"/>. The amount of gas produced is proportional to fiber intake, but the intensity of the odor is independent of fiber intake<ref name="Bolin-1998"/>. Other factors, such as beer intake, increases flatulence odor but not quantity<ref name="Bolin-1998"/>. It's well known that beans and other legumes increase flatulence<ref name="Price-1988"/>, so try different sources of fiber to find foods that do not cause problems. Also, live bacteria, which are found in fermented foods such as yoghurt, sauerkraut, etc., may reduce flatulence in people with irritable bowel syndrome<ref name="Nobaek-2000"/><ref name="Niedzielin-2001"/>. Products such as Beano help reduce flatulence<ref name="Ganiats-1994"/>, but there is no evidence to determine if Beano will undermine the benefits of fiber. This is a concern given that Beano works by converting some of the fiber to simple sugars<ref name="Lettieri-"/>.
=References=
<references>
<ref name="Lettieri-"> {{Cite journal | last1 = Lettieri | first1 = JT. | last2 = Dain | first2 = B. | title = Effects of beano on the tolerability and pharmacodynamics of acarbose. | journal = Clin Ther | volume = 20 | issue = 3 | pages = 497-504 | month = | year = | doi = | PMID = 9663365 }}</ref>
<ref name="Ganiats-1994"> {{Cite journal | last1 = Ganiats | first1 = TG. | last2 = Norcross | first2 = WA. | last3 = Halverson | first3 = AL. | last4 = Burford | first4 = PA. | last5 = Palinkas | first5 = LA. | title = Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance. | journal = J Fam Pract | volume = 39 | issue = 5 | pages = 441-5 | month = Nov | year = 1994 | doi = | PMID = 7964541 }}</ref>
<ref name="Niedzielin-2001"> {{Cite journal | last1 = Niedzielin | first1 = K. | last2 = Kordecki | first2 = H. | last3 = Birkenfeld | first3 = B. | title = A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome. | journal = Eur J Gastroenterol Hepatol | volume = 13 | issue = 10 | pages = 1143-7 | month = Oct | year = 2001 | doi = | PMID = 11711768 }}</ref>
<ref name="Nobaek-2000"> {{Cite journal | last1 = Nobaek | first1 = S. | last2 = Johansson | first2 = ML. | last3 = Molin | first3 = G. | last4 = Ahrné | first4 = S. | last5 = Jeppsson | first5 = B. | title = Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome. | journal = Am J Gastroenterol | volume = 95 | issue = 5 | pages = 1231-8 | month = May | year = 2000 | doi = 10.1111/j.1572-0241.2000.02015.x | PMID = 10811333 }}</ref>
<ref name="Price-1988"> {{Cite journal | last1 = Price | first1 = KR. | last2 = Lewis | first2 = J. | last3 = Wyatt | first3 = GM. | last4 = Fenwick | first4 = GR. | title = Flatulence--causes, relation to diet and remedies. | journal = Nahrung | volume = 32 | issue = 6 | pages = 609-26 | month = | year = 1988 | doi = | PMID = 3068547 }}</ref>
<ref name="Bolin-1998"> {{Cite journal | last1 = Bolin | first1 = TD. | last2 = Stanton | first2 = RA. | title = Flatus emission patterns and fibre intake. | journal = Eur J Surg Suppl | volume = | issue = 582 | pages = 115-8 | month = | year = 1998 | doi = | PMID = 10029376 }}</ref>
<ref name="Davis-2006"> {{Cite journal | last1 = Davis | first1 = JN. | last2 = Hodges | first2 = VA. | last3 = Gillham | first3 = MB. | title = Normal-weight adults consume more fiber and fruit than their age- and height-matched overweight/obese counterparts. | journal = J Am Diet Assoc | volume = 106 | issue = 6 | pages = 833-40 | month = Jun | year = 2006 | doi = 10.1016/j.jada.2006.03.013 | PMID = 16720124 }}</ref>
<ref name="Miller-1994"> {{Cite journal | last1 = Miller | first1 = WC. | last2 = Niederpruem | first2 = MG. | last3 = Wallace | first3 = JP. | last4 = Lindeman | first4 = AK. | title = Dietary fat, sugar, and fiber predict body fat content. | journal = J Am Diet Assoc | volume = 94 | issue = 6 | pages = 612-5 | month = Jun | year = 1994 | doi = | PMID = 8195547 }}</ref>
<ref name="Appleby-1998"> {{Cite journal | last1 = Appleby | first1 = PN. | last2 = Thorogood | first2 = M. | last3 = Mann | first3 = JI. | last4 = Key | first4 = TJ. | title = Low body mass index in non-meat eaters: the possible roles of animal fat, dietary fibre and alcohol. | journal = Int J Obes Relat Metab Disord | volume = 22 | issue = 5 | pages = 454-60 | month = May | year = 1998 | doi = | PMID = 9622343 }}</ref>
<ref name="Du-2010"> {{Cite journal | last1 = Du | first1 = H. | last2 = van der A | first2 = DL. | last3 = Boshuizen | first3 = HC. | last4 = Forouhi | first4 = NG. | last5 = Wareham | first5 = NJ. | last6 = Halkjaer | first6 = J. | last7 = Tjønneland | first7 = A. | last8 = Overvad | first8 = K. | last9 = Jakobsen | first9 = MU. | title = Dietary fiber and subsequent changes in body weight and waist circumference in European men and women. | journal = Am J Clin Nutr | volume = 91 | issue = 2 | pages = 329-36 | month = Feb | year = 2010 | doi = 10.3945/ajcn.2009.28191 | PMID = 20016015 }}</ref>
<ref name="Dong-2011"> {{Cite journal | last1 = Dong | first1 = JY. | last2 = He | first2 = K. | last3 = Wang | first3 = P. | last4 = Qin | first4 = LQ. | title = Dietary fiber intake and risk of breast cancer: a meta-analysis of prospective cohort studies. | journal = Am J Clin Nutr | volume = 94 | issue = 3 | pages = 900-5 | month = Sep | year = 2011 | doi = 10.3945/ajcn.111.015578 | PMID = 21775566 }}</ref>
<ref name="Park-2005"> {{Cite journal | last1 = Park | first1 = Y. | last2 = Hunter | first2 = DJ. | last3 = Spiegelman | first3 = D. | last4 = Bergkvist | first4 = L. | last5 = Berrino | first5 = F. | last6 = van den Brandt | first6 = PA. | last7 = Buring | first7 = JE. | last8 = Colditz | first8 = GA. | last9 = Freudenheim | first9 = JL. | title = Dietary fiber intake and risk of colorectal cancer: a pooled analysis of prospective cohort studies. | journal = JAMA | volume = 294 | issue = 22 | pages = 2849-57 | month = Dec | year = 2005 | doi = 10.1001/jama.294.22.2849 | PMID = 16352792 }}</ref>
<ref name="Bingham-2003"> {{Cite journal | last1 = Bingham | first1 = SA. | last2 = Day | first2 = NE. | last3 = Luben | first3 = R. | last4 = Ferrari | first4 = P. | last5 = Slimani | first5 = N. | last6 = Norat | first6 = T. | last7 = Clavel-Chapelon | first7 = F. | last8 = Kesse | first8 = E. | last9 = Nieters | first9 = A. | title = Dietary fibre in food and protection against colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC): an observational study. | journal = Lancet | volume = 361 | issue = 9368 | pages = 1496-501 | month = May | year = 2003 | doi = | PMID = 12737858 }}</ref>
<ref name="Astrup-1990"> {{Cite journal | last1 = Astrup | first1 = A. | last2 = Vrist | first2 = E. | last3 = Quaade | first3 = F. | title = Dietary fibre added to very low calorie diet reduces hunger and alleviates constipation. | journal = Int J Obes | volume = 14 | issue = 2 | pages = 105-12 | month = Feb | year = 1990 | doi = | PMID = 2160441 }}</ref>
<ref name="Wolk-1999">{{Cite journal | last1 = Wolk | first1 = A. | last2 = Manson | first2 = JE. | last3 = Stampfer | first3 = MJ. | last4 = Colditz | first4 = GA. | last5 = Hu | first5 = FB. | last6 = Speizer | first6 = FE. | last7 = Hennekens | first7 = CH. | last8 = Willett | first8 = WC. | title = Long-term intake of dietary fiber and decreased risk of coronary heart disease among women. | journal = JAMA | volume = 281 | issue = 21 | pages = 1998-2004 | month = Jun | year = 1999 | doi = | PMID = 10359388 }}</ref>
<ref name="Humble-">{{Cite journal | last1 = Humble | first1 = CG. | last2 = Malarcher | first2 = AM. | last3 = Tyroler | first3 = HA. | title = Dietary fiber and coronary heart disease in middle-aged hypercholesterolemic men. | journal = Am J Prev Med | volume = 9 | issue = 4 | pages = 197-202 | month = | year = | doi = | PMID = 8398218 }}</ref>
<ref name="Bolton-Smith-1992">{{Cite journal | last1 = Bolton-Smith | first1 = C. | last2 = Woodward | first2 = M. | last3 = Tunstall-Pedoe | first3 = H. | title = The Scottish Heart Health Study. Dietary intake by food frequency questionnaire and odds ratios for coronary heart disease risk. II. The antioxidant vitamins and fibre. | journal = Eur J Clin Nutr | volume = 46 | issue = 2 | pages = 85-93 | month = Feb | year = 1992 | doi = | PMID = 1313760 }}</ref>
<ref name="Slavin-1987">{{Cite journal | last1 = Slavin | first1 = JL. | title = Dietary fiber: classification, chemical analyses, and food sources. | journal = J Am Diet Assoc | volume = 87 | issue = 9 | pages = 1164-71 | month = Sep | year = 1987 | doi = | PMID = 3040839 }}</ref>
<ref name="Livesey-1990">{{Cite journal | last1 = Livesey | first1 = G. | title = Energy values of unavailable carbohydrate and diets: an inquiry and analysis. | journal = Am J Clin Nutr | volume = 51 | issue = 4 | pages = 617-37 | month = Apr | year = 1990 | doi = | PMID = 2138862 }}</ref>
<ref name="Smith-1998">{{Cite journal | last1 = Smith | first1 = T. | last2 = Brown | first2 = JC. | last3 = Livesey | first3 = G. | title = Energy balance and thermogenesis in rats consuming nonstarch polysaccharides of various fermentabilities. | journal = Am J Clin Nutr | volume = 68 | issue = 4 | pages = 802-19 | month = Oct | year = 1998 | doi = | PMID = 9771857 }}</ref>
<ref name="Donohoe-2011">{{Cite journal | last1 = Donohoe | first1 = DR. | last2 = Garge | first2 = N. | last3 = Zhang | first3 = X. | last4 = Sun | first4 = W. | last5 = O'Connell | first5 = TM. | last6 = Bunger | first6 = MK. | last7 = Bultman | first7 = SJ. | title = The microbiome and butyrate regulate energy metabolism and autophagy in the mammalian colon. | journal = Cell Metab | volume = 13 | issue = 5 | pages = 517-26 | month = May | year = 2011 | doi = 10.1016/j.cmet.2011.02.018 | PMID = 21531334 }}</ref>
<ref name="Roediger-1993">{{Cite journal | last1 = Roediger | first1 = WE. | last2 = Duncan | first2 = A. | last3 = Kapaniris | first3 = O. | last4 = Millard | first4 = S. | title = Reducing sulfur compounds of the colon impair colonocyte nutrition: implications for ulcerative colitis. | journal = Gastroenterology | volume = 104 | issue = 3 | pages = 802-9 | month = Mar | year = 1993 | doi = | PMID = 8440437 }}</ref>
<ref name="Roediger-1982">{{Cite journal | last1 = Roediger | first1 = WE. | title = Utilization of nutrients by isolated epithelial cells of the rat colon. | journal = Gastroenterology | volume = 83 | issue = 2 | pages = 424-9 | month = Aug | year = 1982 | doi = | PMID = 7084619 }}</ref>
<ref name="Roediger-1980">{{Cite journal | last1 = Roediger | first1 = WE. | title = The colonic epithelium in ulcerative colitis: an energy-deficiency disease? | journal = Lancet | volume = 2 | issue = 8197 | pages = 712-5 | month = Oct | year = 1980 | doi = | PMID = 6106826 }}</ref>
<ref name="Sepple-1989">{{Cite journal | last1 = Sepple | first1 = CP. | last2 = Read | first2 = NW. | title = Gastrointestinal correlates of the development of hunger in man. | journal = Appetite | volume = 13 | issue = 3 | pages = 183-91 | month = Dec | year = 1989 | doi = | PMID = 2596841 }}</ref>
<ref name="Leathwood-1988">{{Cite journal | last1 = Leathwood | first1 = P. | last2 = Pollet | first2 = P. | title = Effects of slow release carbohydrates in the form of bean flakes on the evolution of hunger and satiety in man. | journal = Appetite | volume = 10 | issue = 1 | pages = 1-11 | month = Feb | year = 1988 | doi = | PMID = 3355122 }}</ref>
<ref name="Bourdon-1999">{{Cite journal | last1 = Bourdon | first1 = I. | last2 = Yokoyama | first2 = W. | last3 = Davis | first3 = P. | last4 = Hudson | first4 = C. | last5 = Backus | first5 = R. | last6 = Richter | first6 = D. | last7 = Knuckles | first7 = B. | last8 = Schneeman | first8 = BO. | title = Postprandial lipid, glucose, insulin, and cholecystokinin responses in men fed barley pasta enriched with beta-glucan. | journal = Am J Clin Nutr | volume = 69 | issue = 1 | pages = 55-63 | month = Jan | year = 1999 | doi = | PMID = 9925123 }}</ref>
<ref name="Holt-1992">{{Cite journal | last1 = Holt | first1 = S. | last2 = Brand | first2 = J. | last3 = Soveny | first3 = C. | last4 = Hansky | first4 = J. | title = Relationship of satiety to postprandial glycaemic, insulin and cholecystokinin responses. | journal = Appetite | volume = 18 | issue = 2 | pages = 129-41 | month = Apr | year = 1992 | doi = | PMID = 1610161 }}</ref>
<ref name="Heaton-1973">{{Cite journal | last1 = Heaton | first1 = KW. | title = Food fibre as an obstacle to energy intake. | journal = Lancet | volume = 2 | issue = 7843 | pages = 1418-21 | month = Dec | year = 1973 | doi = | PMID = 4128728 }}</ref>
<ref name="FiberPauling">Linus Pauling Institute at Oregon State University http://lpi.oregonstate.edu/infocenter/phytochemicals/fiber/ </ref>
<ref name="USDAFiber"> USDA, Dietary, Functional, and Total Fiber http://www.nal.usda.gov/fnic/DRI//DRI_Energy/339-421.pdf </ref>
<ref name="NDWheat"> Resistant Starch http://www.ndwheat.com/uploads%5Cresources%5C635%5Cresistant-starch-fact-sheet.pdf </ref>
</references>
Fiber is an essential part of a healthy diet, and is frequently misunderstood. Fiber does far more than prevent constipation, helping with weight loss and overall health. Fiber is broadly defined as edible food that cannot be digested in the small intestine, and while some fiber is completely indigestible, other types can be partly digested further down the digestive tract.
=Weight Loss and Fiber=
One of the key benefits of fiber is to help with weight loss and weight control. Fiber can help with weight loss in many ways:
* Fiber can slow the emptying of the stomach, and delay the absorption of nutrients in the small intestine. This produces a feeling of fullness for longer<ref name="Sepple-1989"/> and fiber (30g/day) reduces hunger from low calorie diets<ref name="Astrup-1990"/>.
* Higher fiber intake is linked to long term weight control<ref name="Du-2010"/><ref name="Appleby-1998"/><ref name="Miller-1994"/><ref name="Davis-2006"/>.
* Fiber displaces the more energy dense components of food<ref name="Holt-1992"/> and can reduce the absorption of fat and protein<ref name="Livesey-1990"/>.
* Calories from fiber that is fermented varies between 1.5 and 2.5 Calories/gram<ref name="Smith-1998"/><ref name="Livesey-1990"/>.
* Fiber reduces the [[Glycemic Index]] of foods, which may be why fiber reduces subsequent hunger<ref name="Holt-1992"/><ref name="Bourdon-1999"/><ref name="Leathwood-1988"/>.
* Fiber reduces the energy that is absorbed from other (non-fiber) food<ref name="Heaton-1973"/>.
=Other Health Benefits=
There are a number of other health benefits from increased fiber intake.
* Some fiber is fermented in the colon by bacteria. This fermentation produces carbon dioxide, methane, hydrogen, and short-chain fatty acids. These short chain fatty acids are the preferred fuel for the cells in the colon<ref name="Roediger-1982"/> and if they are lacking they may cause [http://en.wikipedia.org/wiki/Ulcerative_colitis Ulcerative colitis]<ref name="Roediger-1993"/><ref name="Roediger-1980"/> and the colon cells to self-digest<ref name="Donohoe-2011"/>.
* Some, but not all, types of fiber will reduce constipation. For instance, Guar Gum is highly fermentable and does not change stool consistency<ref name="Slavin-1987"/>.
* Some types of fiber can normalize cholesterol levels<ref name="USDAFiber"/>.
* Cereal fiber provides substantial protection from Coronary Heart Disease<ref name="Bolton-Smith-1992"/><ref name="Humble-"/><ref name="Wolk-1999"/>. (There is little evidence for other types of fiber<ref name="USDAFiber"/>.)
* Fiber may provide protection against colorectal cancer, though the evidence is not conclusive<ref name="Bingham-2003"/><ref name="Park-2005"/>. In addition, fiber may protect against breast cancer<ref name="Dong-2011"/>.
=Increasing Your Fiber Intake=
Rapidly increasing your fiber intake can cause digestive pain, bloating and flatulence. These problems can be minimized or avoided by increasing your fiber intake gradually. It is also important to increase your fluid intake along with your fiber intake, as fiber will absorb several times its weight in water.
=Fiber classifications=
There are several ways of classifying fiber<ref name="FiberPauling"/>:
* '''Soluble and insoluble.''' A soluble fiber will disperse in water, where and insoluble fiber will not. At one time it was thought that this distinction would predict the physiological effects of the fiber, but this does not appear to be the case. However, the terms soluble and insoluble still widely used.
* '''Viscous and non-viscous.''' Some fibers form a thick, viscous gel tends to slow digestion and reduce cholesterol levels.
* '''Fermentable and non-fermentable.''' While the fiber cannot be digested directly by humans, it can be fermented by bacteria that naturally live in the colon.
Food packaging will only divide up fiber into soluble and insoluble, so it's important to understand the limitations of that categorization.
=Sources of Fiber=
Many good sources of fiber are also generally considered healthy foods, and there is a sample list below. In addition, it's worth noting that when pasta or rice is cooked and then left to go cold, some of the carbohydrate changes to form 'resistant starch', a form of fiber. A cup of cold pasta for instance, contains about 1.9 grams of resistant starch<ref name="NDWheat"/>.
==Legumes (beans)==
[[File:Beans.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Split peas, cooked||1 cup||16.3
|-
|Lentils, cooked||1 cup||15.6
|-
|Black beans, cooked||1 cup||15.0
|-
|Kidney beans, canned||1 cup||13.6
|-
|Lima beans, cooked||1 cup||13.2
|-
|Refried beans, canned||1 cup||12.2
|-
|Baked beans||1 cup||10.4
|-
|}
==Grains==
[[File:Pasta.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Spaghetti, whole-wheat, cooked||1 cup||6.2
|-
|Barley, pearled, cooked||1 cup||6.0
|-
|Bran flakes||3/4 cup||5.3
|-
|Oatmeal, quick, regular or instant, cooked||1 cup||4.0
|-
|Popcorn, air-popped||3 cups||3.5
|-
|Brown rice, cooked||1 cup||3.5
|-
|}
==Vegetables==
[[File:SaladVeg.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Artichoke hearts, cooked||1 cup||14.4
|-
|Peas, cooked||1 cup||8.8
|-
|Broccoli, boiled||1 cup||5.1
|-
|Sweet corn, cooked||1 cup||4.2
|-
|Brussels sprouts, cooked||1 cup||4.1
|-
|Potato, with skin, baked||1 medium||2.9
|-
|Tomato paste||1/4 cup||2.7
|-
|Carrot, raw||1 medium||1.7
|-
|}
==Fruits==
[[File:FruitPears.jpg|right|thumb|200px]]
{| class="wikitable"
!!!'''Amount'''!!'''Fiber (grams)'''
|-
|Prunes, uncooked||1 cup, pitted||12.4
|-
|Pear, with skin||1 medium||5.5
|-
|Apple, with skin||1 medium||4.4
|-
|Strawberries (halves)||1 1/4 cup||3.8
|-
|Banana||1 medium||3.1
|-
|Orange||1 medium||3.1
|-
|}
==Nuts==
[[File:Nuts.jpg|right|thumb|200px]]
{| class="wikitable"
!'''Nuts'''!!'''Amount'''!!''''''Fiber (grams)''''''
|-
|Almonds||1 ounce (23 kernels)||3.5
|-
|Pistachio nuts||1 ounce (49 kernels)||2.9
|-
|Pecans||1 ounce (19 halves)||2.7
|-
|Peanuts||1 ounce||2.4
|-
|}
=Fiber Supplements=
While it's best to eat a wholesome diet which will be naturally high in fiber, sometimes it's useful to supplement your fiber intake. I use [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=Fiber&url=http%3A%2F%2Fwww.amazon.com%2FMetamucil-Smooth-Texture-Orange-114-Dose%2Fdp%2FB0013I1H9G Metamucil Sugar Free Powder] on a regular basis and it's helped with my weight control. I occasionally use [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=FiberClear&url=http%3A%2F%2Fwww.amazon.com%2FMetamucil-Natural-Clear-Mixing-Powder-Servings%2Fdp%2FB001EP3IEA Metamucil Clear] which uses a different type of fiber that has no texture or flavor. In both cases I mix the Metamucil and wait for at least 10 minutes, shaking or stirring periodically. If you drink it without waiting the regular Metamucil can be a little gritty, and after a few minutes both varieties will thicken up the drink.
=Flatulence=
Flatulence (gas) is a constant source of both humor and embarrassment. Unfortunately, this embarrassment causes people to avoid high fiber foods, even when they understand the benefits. The major components of intestinal gas are nitrogen, hydrogen, carbon dioxide and methane, all of which are odorless. The actual odor comes from tiny amounts of compounds such as ammonia, hydrogen sulfide, other sulfur compounds, short chain fatty acids, etc. Even though only trace amounts are produced, the human nose can detect them in concentrations as low as 1 part in 100 million<ref name="Bolin-1998"/>. The amount of gas produced is proportional to fiber intake, but the intensity of the odor is independent of fiber intake<ref name="Bolin-1998"/>. Other factors, such as beer intake, increases flatulence odor but not quantity<ref name="Bolin-1998"/>. It's well known that beans and other legumes increase flatulence<ref name="Price-1988"/>, so try different sources of fiber to find foods that do not cause problems. Also, live bacteria, which are found in fermented foods such as yoghurt, sauerkraut, etc., may reduce flatulence in people with irritable bowel syndrome<ref name="Nobaek-2000"/><ref name="Niedzielin-2001"/>. Products such as Beano help reduce flatulence<ref name="Ganiats-1994"/>, but there is no evidence to determine if Beano will undermine the benefits of fiber. This is a concern given that Beano works by converting some of the fiber to simple sugars<ref name="Lettieri-"/>.
=References=
<references>
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<ref name="Ganiats-1994"> {{Cite journal | last1 = Ganiats | first1 = TG. | last2 = Norcross | first2 = WA. | last3 = Halverson | first3 = AL. | last4 = Burford | first4 = PA. | last5 = Palinkas | first5 = LA. | title = Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance. | journal = J Fam Pract | volume = 39 | issue = 5 | pages = 441-5 | month = Nov | year = 1994 | doi = | PMID = 7964541 }}</ref>
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<ref name="Bolton-Smith-1992">{{Cite journal | last1 = Bolton-Smith | first1 = C. | last2 = Woodward | first2 = M. | last3 = Tunstall-Pedoe | first3 = H. | title = The Scottish Heart Health Study. Dietary intake by food frequency questionnaire and odds ratios for coronary heart disease risk. II. The antioxidant vitamins and fibre. | journal = Eur J Clin Nutr | volume = 46 | issue = 2 | pages = 85-93 | month = Feb | year = 1992 | doi = | PMID = 1313760 }}</ref>
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<ref name="Smith-1998">{{Cite journal | last1 = Smith | first1 = T. | last2 = Brown | first2 = JC. | last3 = Livesey | first3 = G. | title = Energy balance and thermogenesis in rats consuming nonstarch polysaccharides of various fermentabilities. | journal = Am J Clin Nutr | volume = 68 | issue = 4 | pages = 802-19 | month = Oct | year = 1998 | doi = | PMID = 9771857 }}</ref>
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<ref name="FiberPauling">Linus Pauling Institute at Oregon State University http://lpi.oregonstate.edu/infocenter/phytochemicals/fiber/ </ref>
<ref name="USDAFiber"> USDA, Dietary, Functional, and Total Fiber http://www.nal.usda.gov/fnic/DRI//DRI_Energy/339-421.pdf </ref>
<ref name="NDWheat"> Resistant Starch http://www.ndwheat.com/uploads%5Cresources%5C635%5Cresistant-starch-fact-sheet.pdf </ref>
</references>