Recommended dietary fiber intake

Food and Nutrition Board Recommendations (2001) Dietary reference intakes - dietary fiber. Institute of Medicine, Washington D C, National Academy Press, 1-64. 

Goni I. 2001. Dietary fiber intake in Spain recommendations and actual consumption patterns. In Sungsoo Cho S and Dreher ML, editors. Handbook of Dietary Fiber. New York Marcel Dekker. 

These results apparently support those in the previous study however, because dietary fiber was higher in the low fat diet than in the high fat diet, it is impossible to separate the effects of fat, fiber and possibly cholesterol. The alterations used in the low fat, controlled diet were essentially those recommended in the U.S. Dietary Goals/Guidelines while the moderately high fat, self-selected diets resembled usual American dietary intake patterns. 

The beneficial effects of dielary fiber, including both soluble and insoluble fiber, are generally recognized. Current recommendations arc for daily intakes of 20-35 g in a balanced diet of cereal products, fruits, vegetables, and legumes. However, the specific preventive role of dietary fiber in certain diseases has been difficult to establish, in pan because dielary risk factors such as high saturated fat and high protein levels are reduced as fiber levels increase. 

This broad understanding of dietary fiber makes it difficult to describe or characterize chemically and to elucidate its behavior in the gastrointestinal tract. Nevertheless with changing dietary habits and recommendations for food intake for good health and nutrition, it is important that the chemistry of this class of food components be more readily characterized and understood. Since much dietary fiber Is of cell wall origin, some of the approaches that have been successfully used to define and explain the chemistry of plant cell walls (5, 6) should be applicable to research on the characterization and function of dietary fiber (7, 9), To this end we have... 

It is my hope and belief that this publication will help in the expansion and utilization of fiber sources in foods, as well as in pharmaceutical and medical preparations. After all, we should recognize that the chance to accomplish this is quite favorable because complex carbohydrates, which are the main constituents of dietary fiber, represent the only group of major food components for which increased daily intake is repeatedly being recommended. 

National Academy of Sciences (USA) [11] has recommended a daily intake of at least five servings of fruit and vegetables, particularly citric fruits, carotene-rich fruits and vegetables, and cmciferous vegetables to reduce the risk of both cancer and heart disease scientific research has demonstrated that the presence of dietary fibers and polyphenols in fruits and vegetables reduces the risk of cancer because of their antioxidant and anti-inflammatory properties. 

Currently, it is not possible to recommend a specific intake of fiber more research is needed. However, dramatic increases in dietary fiber should be avoided since the absorption of minerals may be reduced by high dietary fiber intakes. Moderate increases in the consumption of fiber can be easily achieved by increasing the consumption of nuts, vegetables, fruits, and whole grain cereal products. The fiber content of various foods is given in Food Composition Table F-21. 

The lOM does not specify dietary requirements or recommendations for NSP consumption, but has provided recommended intakes for fiber, which includes NSP. The DRIs for total fiber consumption of individual groups and lifestages are outlined in... 

In the studies on humans there appeared to be decreased calcium balances when 200 g or more of spinach per day was included in the diet. In two of the studies in which women were fed spinach, calcium intakes were below the Recommended Dietary Allowance of 800 mg/day (37). Some studies were conducted for short period of a week or less, which may not be sufficient time to adjust to a change in diet. From measurement of calcium excretion in urine after a test meal, it was shown that the calcium in oxalate-containing vegetables was less well-absorbed than that of milk or of vegetables not containing oxalic acid. However, this would not necessarily affect calcium balance, since the total amount of calcium in the diet would have to be considered. The effect of a combination of oxalic acid and fiber on calcium bioavailability should be further investigated. 

The effect on zinc balance of a 10-fold difference in dietary molar ratio of phytate/zinc was tested in a metabolic balance study with 10 adult men. The mean zinc balance was 2.7 mg per day vrtien the dietary molar ratio of phytate/zinc was about 12 and 2.0 mg per day when the ratio was about 1. Menus consisted of foods commonly consumed in the United States. The mean daily intake of zinc was 17 mg and of neutral detergent fiber 16 g. The molar ratios of phytate/zinc were attained by using 36 g per day of whole or dephytinized wheat bran. Analysis of hospital and self-chosen diets Indicate that the majority of the United States population consume diets with molar ratios of phytate/zinc less than 10, but which provide less than the recommended dietary allowance of zinc. The balance results are discussed in relation to magnitude of the zinc intake, the type of food consumed and the role of adaptive responses in maintaining adequate zinc nutriture. 

The average daily intake of fiber in the United States is about 12 g. The Food and Nutrition Board has not established a requirement for fiber but states that fiber intake should be derived from fruits, vegetables, legumes, and cereals, not from fiber concentrates. If a recommended dietary allowance for fiber is established, it will refer to specific types of fiber rather than to fiber in general. 

I he RDA for zinc is 15 mg. With mixed diets containing phytate and fiber, about 30% of dietary zinc Is absorbed. The efficiency of absorption increases with diets containing very little zinc. Dietary zinc must replace the obligatory losses, which, at the minimum, are about 0.7 mg/day. The RDA for copper has not been determined. The National Research Council recommends 1.5 to 3.0 mg per day as a safe and adequate range of dietary copper intake for adults. The usual dietary intake of copper in the United States is about 1 mg/day. This amount is sufficient to... 

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