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eLetters to:
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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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eLetters published:
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Not a fair comparison
- Cory Mermer
(25 February 2000)
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Response to comments of Cory Mermer
- Theresa Nicklas, Carol O'Neil
(1 March 2000)
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Response to comments of Cory Mermer
- Theresa Nicklas, Carol O'Neil
(1 March 2000)
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Not a fair comparison |
25 February 2000 |
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Cory Mermer, Researcher/Writer Independent
Send letter to journal:
Re: Not a fair comparison
cmermer{at}aol.com Cory Mermer
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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.
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Response to comments of Cory Mermer |
1 March 2000 |
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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.
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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
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Response to comments of Cory Mermer |
1 March 2000 |
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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
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