The American journal of clinical nutrition
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The effects of two sources of dietary fiber on the characteristics of cecal contents were assessed directly with miniature swine cannulated to facilitate frequent collections of cecal digesta. The short-chain fatty acid (SCFA) concentrations increased and the pH decreased at the same time that meal constituents entered the cecum; PEG was used as a dietary marker. The bean diet resulted in higher concentrations of acetate and total SCFA in cecal digesta, lower concentrations of butyrate, a larger SCFA pool size, and a more acidic pH than did the bran diet. Thus, we conclude that SCFA concentrations and acidity of the digesta are directly related and that dietary fibers can affect simultaneously several variables that are implicated as factors influencing colonic health.
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Comparative Study
Impression cytology: a practical index of vitamin A status.
Impression cytology was performed on 148 Indonesian preschool children of whom half had mild xerophthalmia and half were age-matched control subjects. Subjects were divided into subgroups that reflected the degree of confidence in their true vitamin A status as determined by serum vitamin A levels, clinical examination, and response to therapy. ⋯ In contrast, 17 of 18 (94%) children with normal ocular exam and serum vitamin A greater than 25 micrograms/dL (0.87 mumol/L) (group 7, least likely deficient) had normal cytology. Importantly, 12 of 26 (46%) clinically normal children with serum vitamin A levels less than 20 micrograms/dL (0.70 mumol/L) had abnormal impression cytology.
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Maternal weight gain is one of the most important independent predictors of infant birth weight and interacts with other maternal characteristics, including age, so that infant birth weight reaches a plateau at a higher level of maternal weight gain for young adolescents than for adults. It has been suggested that encouraging young adolescents to gain larger amounts of weight during pregnancy may be one way to decrease their risk of low-birth-weight deliveries. This recommendation may be premature because the mechanisms underlying the interaction between maternal age and weight gain are incompletely understood and may include such diverse factors as incomplete maternal growth, reproductive immaturity, diminished maternal body size, nutritional deficiencies, socioeconomic and behavioral factors, and maternal emotional stress. This review summarizes the literature on adolescent maternal weight gain and infant birth weight and discusses the importance of considering a multifactorial model in reformulating the weight-gain recommendations for pregnant adolescents.
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Clinical Trial Controlled Clinical Trial
Metabolic effects of fructose and glucose: implications for food intake.
Differential effects of fructose and glucose preloads on carbohydrate metabolism and later food intake were examined in both lean and obese subjects. In study 1, a preload of either 50 g of fructose or glucose was administered in solution, and food intake at a buffet lunch presented 2.25 h after preload was assessed. ⋯ Incorporation of fructose or glucose into a mixed meal format in study 2 revealed no differences in subsequent caloric intake as a function of either type of preload or percent overweight. Differing insulin levels are discussed as a possible mechanism for differential food intake.
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The National Center for Health Statistics conducts a broad program of record-based systems and population surveys providing information on the health and nutritional status of the US population. The record-based systems include vital statistics and health-care surveys. ⋯ Although all of these data systems provide nutrition-related information, the NHANES collects the most directly relevant nutritional status data through interview and examination of a national probability sample of children and adults. The third NHANES is scheduled to begin in September 1988 and is designed to provide cross-sectional estimates of dietary intake and nutritional status for nutrition-monitoring purposes and to serve as the baseline for longitudinal studies of diet and health.