Prevalence of neural tube defects, folate status, and folate fortification of enriched cereal-grain products in the United States.
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Dietary Supplements↗
Biomedical subjects
Barbara O Schneeman
Publications and source records attributed to Barbara O Schneeman.
Interaction of fat availability and sex on postprandial satiety and cholecystokinin after mixed-food meals.
BACKGROUND: Cholecystokinin (CCK) is associated with fat-induced satiety. OBJECTIVE: The primary objective of the present study was to determine, in an acute meal setting, whether the availability of dietary fat for alimentary processing, and hence the stimulation of CCK, affects the postmeal satiety response in men and women. DESIGN: In a within-subjects design, subjects (8 men, 7 women) consumed 1 of 3 isoenergetic mixed-food test meals 1 wk apart in random order. The test meals contained 30% of energy from fat, of which more than two-thirds was derived from whole almonds, almond oil, or a mix of safflower and corn oils. Visual analogue scales were used to assess indexes of satiety at defined time points up to 6 h after meal consumption. Blood was sampled at corresponding time points for measurement of CCK, glucose, insulin, and triacylglycerol. Subsequent food intake was also assessed. RESULTS: All meals suppressed hunger and induced a pattern of satiety that was sex-specific and corresponded with the CCK response. Women had higher plasma CCK concentrations and experienced greater satiety after the almond oil and control meals (fat as oil) than after the whole almond meal (fat in whole food structure). Men showed no differential response among meals for CCK and satiety. Plasma triacylglycerol differed by time among meals but not by sex, and no significant differences in glucose and insulin were found. CONCLUSIONS: The satiety response to dietary fat provided in oil or whole food form is influenced by sex and is dependent on the availability of fat to stimulate CCK release in women but not in men.
Adult↗
Evolution of dietary guidelines.
Advice on eating behavior, food choices, and food preparation have been incorporated into philosophical and religious writings over the ages; however, in the past 150 years, these recommendations have been based on science related to public health policy and medicine. In the first half of the 20th century, the focus was on sanitation and prevention of nutrient deficiency diseases. In the second half, the focus has shifted to prevention of chronic disease and dietary excesses that increase disease risk. Current guidelines recognize the importance of lifestyle as well as food and nutrition choices. Dietary guidelines that were developed in the early 1980s emphasized components of food such as saturated fat, individual nutrients, or fiber. Revisions of these guidelines have placed more emphasis on food choices rather than individual nutrients, and recommendations have become more food-based. The process developed by the Food and Agricultural Organization and World Health Organization for preparation and use of food-based dietary guidelines begins with analysis of the most critical public health issues that are related to diet and outlines strategies to identify food-based approaches to address these issues. Countries that have implemented this process indicate that consensus building accomplished through the process has allowed a multisector approaches for addressing diet-related public health problems.
Diet↗
Incorporating dairy foods into low and high fat diets increases the postprandial cholecystokinin response in men and women.
The postprandial period is a dynamic state of hormone and lipoprotein metabolism that can be influenced by dietary composition. The objective of this study was to determine whether the source of dietary fat [dairy (D) vs. nondairy (ND)] would modify the lipemic, insulin and cholecystokinin (CCK) response to high or low fat meals. Men and women (n = 24) consumed 4 test meals with a similar polyunsaturated:saturated (P:S; 0.12:1) fat ratio. The diets were high (38% energy) or low (20% energy) in fat, with or without fat from dairy sources. CCK responses were greater after consumption of meals containing D than ND, and for high compared with low fat meals. Women had higher CCK responses than men and were more sensitive to the differences in dietary treatments. Consumption of low fat meals resulted in greater insulin responses than high fat meals. However, after consumption of the low fat meals, the insulin response of D was about half of the ND response; no differences in insulin response were detected after the high fat meals. Triacylglyceride response was influenced primarily by the fat content of the diet. Consumption of dairy products containing fat was associated with an enhanced CCK response, which may have implications for the regulation of food intake. Blunting glucose and insulin response in low fat meals containing fat from dairy products may be useful for glycemic control.
Adult↗
Dietary guidelines: past experience and new approaches.
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Australia↗
Gastrointestinal physiology and functions.
While the health benefit of a functional food may be a metabolic response that lowers risk for disease, the actual target for the food or food component may be on the functioning of the gastrointestinal tract (GIT). For example, slowing absorption from the intestine, as measured by examining the appearance of the nutrient or food component in the blood, the hormone response associated with absorption of the compound or excretion of the compound, may provide a health benefit. However, the food component may slow absorption by delaying gastric emptying, altering the mixing within the intestinal contents or decreasing the availability of digestive enzymes in the intestine. These measures of GIT function provide validation of the mechanisms by which the functional food or food components affect metabolism. Bioavailability of physiologically active compounds from foods will be determined by the digestibility of foods that contain these compounds, their subsequent absorption and utilization by tissues. The physical structure of foods contributes to the functional effects of foods as well as to the availability of compounds from foods. For example, recent studies have demonstrated that changing the viscosity of the gut contents alters absorption and GIT response. Additionally, food structures such as the plant cell wall change the availability of absorbable compounds along the gastrointestinal contents. The areas of probiotics and prebiotics have highlighted the potential importance of gut microflora in health. While evidence suggests biological activity relevant to disease risk reduction, the long-term implications of the microbial activity have yet to be established.
Biological Availability↗
Plasma cholecystokinin is associated with subjective measures of satiety in women.
BACKGROUND: Cholecystokinin is associated with satiety. Fat stimulates cholecystokinin release, and fiber appears to prolong cholecystokinin elevation during the alimentary period. OBJECTIVE: We tested whether adding fiber or fat to a low-fat, low-fiber meal increases cholecystokinin release and enhances subjective measures of satiety and whether the cholecystokinin response correlates with subjective measures of satiety. DESIGN: Three isoenergetic breakfast meals were tested in a randomized crossover design: low fiber, low fat; high fiber, low fat; and low fiber, high fat. Blood samples were drawn from fasted subjects (7 men and 8 women) before and at different time points after test meal consumption for 6 h. Plasma was analyzed for cholecystokinin, insulin, glucose, and triacylglycerols. Visual analogue scales were used to assess subjects' hunger, desire to eat, fullness, and prospective consumption. RESULTS: In the women, the meals higher in fiber or in fat resulted in greater feelings of satiety and in significantly higher cholecystokinin responses than did the low-fat, low-fiber meal. In the men, the increase in cholecystokinin concentration did not differ between meals, but the 2 low-fat meals elicited a greater feeling of satiety than did the high-fat meal. The insulin response was significantly higher for the low-fiber, low-fat meal than for the other 2 meals, and the triacylglycerol response was greatest for the high-fat, low-fiber meal. CONCLUSION: In women, the feeling of satiety caused by cholecystokinin release is enhanced by increasing either the fiber or fat content of a low-fat, low-fiber meal.
Adult↗
Almonds and almond oil have similar effects on plasma lipids and LDL oxidation in healthy men and women.
Epidemiologic and clinical studies have shown that nut consumption is associated with favorable plasma lipid profiles and reduced cardiovascular risk. These effects may result from their high monounsaturated fat (MUFA) content but nuts contain constituents other than fatty acids that might be cardioprotective. We conducted a study to compare the effects of whole-almond vs. almond oil consumption on plasma lipids and LDL oxidation in healthy men and women. Using a randomized crossover trial design, 22 normolipemic men and women replaced half of their habitual fat (approximately 14% of approximately 29% energy) with either whole almonds (WA) or almond oil (AO) for 6-wk periods. Compliance was ascertained by monitoring dietary intake via biweekly 5-d food records, return of empty almond product packages and weekly meetings with a registered dietitian. Fat replacement with either WA and AO resulted in a 54% increase in percentage of energy as MUFA with declines in both saturated fat and cholesterol intake and no significant changes in total energy, total or polyunsaturated fat intake. The effects of WA and AO on plasma lipids did not differ compared with baseline; plasma triglyceride, total and LDL cholesterol significantly decreased, 14, 4 and 6% respectively, whereas HDL cholesterol increased 6%. Neither treatment affected in vitro LDL oxidizability. We conclude that WA and AO do not differ in their beneficial effects on the plasma lipid variables measured and that this suggests that the favorable effect of almonds is mediated by components in the oil fraction of these nuts.
Adult↗
Effects of soy consumption on gonadotropin secretion and acute pituitary responses to gonadotropin-releasing hormone in women.
Soy contains the isoflavone phytoestrogens, genistein and daidzein. These isoflavones are partial estrogen agonists in cell and animal models, but effects from dietary soy in humans are unclear. Experiments were conducted in pre- and postmenopausal women to examine whether dietary isoflavones from soy behave as estrogen agonists, antagonists or have no effect on the estrogen-sensitive pituitary. Pituitary sensitivity to gonadotropin-releasing hormone (GnRH), an estrogen-sensitive endpoint, was measured during GnRH challenge tests administered before, during and after dietary soy consumption. The response to an isoflavone-rich soy food diet was examined in five premenopausal and seven postmenopausal women using transdermal estrogen replacement therapy. Estrogen agonists suppress gonadotropin concentrations and enhance GnRH priming (enhanced gonadotropin secretion in response to repeated doses of GnRH), whereas antagonists elevate gonadotropin concentrations and have no effect on GnRH priming. Each subject consumed 50 g textured soy protein containing 60 mg total isoflavones daily for 10-14 d. Baseline estradiol concentrations were consistent among study periods. In both pre- and postmenopausal women, soy consumption did not affect mean baseline or peak luteinizing hormone (LH) concentrations, indicating a lack of estrogen-like effect at the level of the pituitary. However, in postmenopausal subjects, mean LH secretion decreased after discontinuing soy, suggesting a residual estrogenic effect. In one premenopausal woman, enhanced LH secretion was observed after soy treatment, suggesting there may be subpopulations of women who are highly sensitive to isoflavones.
Adult↗