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ELECTRONIC ARTICLE: Theresa A. Nicklas, LN*; Leann Myers, Carol O'Neil, and Nancy Gustafson Impact of Dietary Fat and Fiber Intake on Nutrient Intake of Adolescents Pediatrics 2000; 105: e21 [Abstract] [Full text] [PDF]

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Not a fair comparison

Cory Mermer   (25 February 2000)

Response to comments of Cory Mermer

Theresa Nicklas, Carol O'Neil   (1 March 2000)

Response to comments of Cory Mermer

Theresa Nicklas, Carol O'Neil   (1 March 2000)

Not a fair comparison 25 February 2000
Cory Mermer, Researcher/Writer Independent Send letter to journal: Re: Not a fair comparison cmermer{at}aol.com Cory Mermer	One reason why the high fiber diet provided adequte quantities of nutrients is that most refined grain products are fortified with several vitamins and iron. This is essentially no different than taking nutritional supplements along with the food. Therefore, it is not fair to compare enriched foods to those not enriched. It would be much more appropriate to compare foods in their natural state. It also would have been interesting and informative to see how the absorption of nutrients compared, rather than simply intake. For example, it is stated that the high-fiber group had higher intakes of vitamin A. However, being a fat-soluble vitamin, it requires fat in order to be properly absorbed. Additionally, the high-fiber diet may decrease absorption by decreasing "transit time" or the time it takes for food to travel through the intestines The higher-fat diet in this case was working from a significant disadvantage and never really had a chance.
Response to comments of Cory Mermer 1 March 2000
Theresa Nicklas, Professor Children Nutrition Research Center - Baylor of Medicine, Carol O'Neil Send letter to journal: Re: Response to comments of Cory Mermer tnicklas{at}bcm.tmc.edu Theresa Nicklas, et al.	In response to the comments of Cory Mermer we offer the following comments. First of all, there is no argument that one reason the high fiber diet contributed to a higher micronutrient intake by study participants was that many grain products are fortified. However, the suggestion that it would have been "fairer" to compare foods in their "natural state" is irrelevant, since it was critical to the integrity of the study to use the actual nutrient content of the menu item consumed. The advantages and disadvantages of food fortification are beyond the scope of this letter, but it should be noted that advantages include a reduction in the incidence of goiter and cretinism, neural tube defects, rickets and osteomalacia, xerophthalmia and blindness, and other deficiency diseases. Certainly, the relation of food ingested to food absorbed is an interesting and understudied topic. Many factors can impact the absorption of nutrients, including dietary fiber. As evident in a recently published article (Riedl, et al., J Nutr 129:2170-2176, 1999), some types of dietary fiber may decrease the bioavailability of carotenoids in women. The small sample size (n=6) in this study makes it difficult to generalize these data. This specialized type of research is, however, incompatible, with an epidemiologic study design, as was used for this research. It is hard to disagree that fat is needed for the absorption of fat- soluble vitamins, like vitamin A. According to a recently published paper by Jequier (Eur J Clin Nutr 1999 (suppl 1:S84-88; discussion S88-93), fat energy should not be below 10% of total energy intake in order to ensure an unrestricted absorption of fat soluble vitamins, particularly vitamins A and E. It should be noted that the "low-fat" intake group actually had a fat intake of 24% and 23% of energy from fat for females and males, respectively. These values far exceed the minimal requirements of fat in the diet, suggesting that vitamin A absorption in the study population was not impaired. Finally, a statement like "The higher-fat diet in this case was working from a significant disadvantage and never really had a chance", suggests that it deserves one. Literature cited Riedl J, Linseisen H, Hoffman J, Wolfram G. Some dietary fibers reduce the absorption of carotenoids in women. J Nutr 129:2170-2176, 1999. Jequier E. Response to and range of acceptable fat intake in adults. Eur. J Clin Nutr 53 (Suppl 1):S84-88; discussion S88-93, 1999. Theresa A. Nicklas DrPH, Ln Professor of Pediatrics Children's Nutrition Research Center Baylor College of Medicine Department of Pediatrics Carol O'Neil PhD, MPH, RD, LDN Associate Professor School of Human Ecology Louisiana State University
Response to comments of Cory Mermer 1 March 2000
Theresa Nicklas, Professor Children Nutrition Research Center - Baylor College of Medicine, Carol O'Neil Send letter to journal: Re: Response to comments of Cory Mermer tnicklas{at}bcm.tmc.edu Theresa Nicklas, et al.	In response to the comments of Cory Mermer we offer the following comments. First of all, there is no argument that one reason the high fiber diet contributed to a higher micronutrient intake by study participants was that many grain products are fortified. However, the suggestion that it would have been "fairer" to compare foods in their "natural state" is irrelevant, since it was critical to the integrity of the study to use the actual nutrient content of the menu item consumed. The advantages and disadvantages of food fortification are beyond the scope of this letter, but it should be noted that advantages include a reduction in the incidence of goiter and cretinism, neural tube defects, rickets and osteomalacia, xerophthalmia and blindness, and other deficiency diseases. Certainly, the relation of food ingested to food absorbed is an interesting and understudied topic. Manyu factors can impact the absorption of nutrients, including dietary fiber. As evident in a recently published article (Riedl, et al., J Nutr 129:2170-2176, 1999), some types of dietary fiber may decrease the bioavailability of carotenoids in women. The small sample size (n=6) in this study makes it difficult to generalize these data. This specialized type of research, is, however, incompatible, with an epidemiologic study design, as was used for this research. It is hard to disagree that fat is needed for the absorption of fat- soluble vitamins, like vitamin A. According to a recently published paper by Jequier (Eur J Clin Nutr 1999 (suppl 1:S84-88; discussion S88-93), fat energy should not be below 10% of total energy intake in order to ensure an unrestricted absorption of fat soluble vitamins, particularly vitamins A and E. It should be noted that the "low-fat" intake group actually had a fat intake of 24% and 23% of energy from fat for females and males, respectively. These valuse far exceed the minimal requirements of fat in the det, suggesting that vitamin A absorption in the study population was not imparied. Finally, a statement like "The higher-fat diet in this case was working from a significant disadvantage and never really had a chnace", suggests that it deserves one. Literture cided Riedl. J, Linseisen H, Hoffman J, Wolfram G. Some dietery fibers reduce the absorption of carotenoids in women. J Nutr 129:2170-2176, 1999. Jequier E. Response to and range of acceptable fat intake in adults. Eur. J Clin Nutr 53 (Suppl 1):S84-88; discussion S88-93, 1999. Theresa A. Nicklas DrPH, LN Professor of Pediatrics Children's Nutrition Research Center Baylor College of Medicine Department of Pediatrics Carol O'Neil PhD, MPH, RD, LDN Associate Professor School of Human Ecology Louisiana State University