Bryan T. Vinyard

Fast Food Consumption of U.S. Adults: Impact on Energy and Nutrient Intakes and Overweight Status

Objective: To compare the diet quality and overweight status of free-living adults, ages 20 years and older, grouped based on their fast food intake status. Methods: USDA’s 1994 to 1996 Continuing Survey of Food Intakes by Individuals (CSFII 1994–1996) data was used. Three separate analyses were conducted: (1) effect of fast food on diet quality of males and females based on day-one data, (2) comparison of dietary and overweight status of adults who ate fast food on one- two- or none of survey days and (3) within-person analysis comparing energy and macronutrient intakes of adults who ate fast food on one of the two survey days. SUDAAN software package was used in pair-wise mean comparisons and regression analyses (α = 0.05). Results: At least one in four adults reported eating fast food. The diet of males and females who consumed fast food was high in energy and energy density. Fast food provided more than one-third of the day’s energy, total fat and saturated fat; and was high in energy density. Negligible amounts of milk and fruits, but substantially large amounts of non-diet carbonated soft drinks were reported consumed at fast food places. After controlling for age, gender, socio-economic and demographic factors, energy and energy density increased and micronutrient density decreased with frequency of fast food consumption. Adults who reported eating fast food on at least one survey day had higher mean body mass index values than those who did not eat fast food on both survey days. A small, but significant, positive association was seen between fast food consumption and overweight status. Within-person comparisons showed that energy intakes were higher on a fast food day than on a non-fast food day. Conclusion: Fast food consumption was associated with a diet high in energy and energy density and low in essential micronutrient density. Frequent fast food consumption may contribute to weight gain.

GLUCOSE AND INSULIN RESPONSES TO WHOLE GRAIN BREAKFASTS VARYING IN SOLUBLE FIBER, BETA-GLUCAN: A DOSE RESPONSE STUDY IN OBESE WOMEN WITH INCREASED RISK FOR INSULIN RESISTANCE

BACKGROUND A high intake of whole grains containing soluble fiber has been shown to lower glucose and insulin responses in overweight humans and humans with type 2 diabetes. AIM OF THE STUDY We investigated the linearity of this response after consumption of 5 breakfast cereal test meals containing wheat and/or barley to provide varying amounts of soluble fiber, beta-glucan (0, 2.5, 5, 7.5 and 10 g). METHODS Seventeen normoglycemic, obese women at increased risk for insulin resistance consumed 5 test meals within a randomized cross-over design after consuming controlled diets for 2 days. Blood samples for glucose and insulin response were obtained prior to and 30, 60, 120 and 180 min after consuming the test meals. RESULTS Consumption of 10 g of beta-glucan significantly reduced peak glucose response at 30 min and delayed the rate of glucose response. Area under the curve for 2 h-postprandial glycemic response was not affected by beta-glucan content. However, peak and area under the curve of insulin responses were significantly affected by the beta-glucan amount in an inverse linear relationship. CONCLUSION These data suggest that acute consumption of 10 g of beta-glucan is able to induce physiologically beneficial effects on postprandial insulin responses in obese women at risk for insulin resistance.

Functional and Digestive Characteristics of Extruded Rice Flour

ABSTRACT Waxy (short grain), long grain, and parboiled (long grain) rice flours were extruded using three different temperatures and five different water feed rates. The water absorption and water solubility index of the extrudates was 0.67–5.86 and 86.45–10.03%, respectively. The fat absorption index was similar to that of unextruded flours with an average value of 0.96 g/g ± 0.12. Bulk density decreased with an increase in moisture, except waxy rice, which had a quadratic relationship. The viscosity profiles for long grain and parboiled rice were similar. Both initially increased in viscosity (>130 RVU), then decreased to ≈40 RVU. The final viscosity was ≈60 RVU. Waxy rice viscosity remained low ( 0.05) except for long gr...

Short-Term Satiety and Glycemic Response After Consumption of Whole Grains with Various Amounts of beta-Glucan

The effects of a meal with and without soluble dietary fiber in the form of beta-glucan on short-term satiety and glucose response were investigated in 19 overweight subjects. Subjects consumed four isocaloric test meals consisting of a glucose solution or wheat (0 g of beta-glucan), a wheat-barley mixture (1 of beta-glucan), or barley (2 of P-glucan) served as cooked cereal with low-fat strawberry yogurt. Subjects used visual analog scales (VAS) to rate their hunger, fullness, satisfaction, thirst, nausea, and drowsiness at timed intervals before and after consumption of each test meal. Blood glucose was measured periodically, and energy intake was recorded 2 hr after consumption of each test meal. In women peak glucose responses and area under the curve were significantly lower after consumption of 2 of beta-glucan compared with consumption of 0 or 1 g of beta-glucan. VAS ratings did not significantly differ among cereals. In men no effect of glucan on glucose response was observed, and beta-glucan had only a marginal effect oil VAS ratings. Energy intake was not affected by beta-glucan level in either women or men. The findings indicate that acute reduction of glycemic response in overweight women requires the comsumption of at least 2 g of beta-glucan per meal, and greater amounts of beta-glucan per meal may be required to achieve substantial satiety effects in overweight women and men.

HIGH-RESOLUTION AIRBORNE REMOTE SENSING OF BLOOM-FORMING PHYTOPLANKTON1

Remote sensing of highly turbid finfish aquaculture impoundments using the Calibrated Airborne Multispectral Scanner (CAMS) mounted on a Lear jet flown at 900 m was conducted in central Mississippi on 16 May 1990. Concurrent in situ data consisted of phytoplankton pigment concentrations and standing crop, water color, turbidity, and surface‐water temperature. Surface and near‐surface assemblages of cyanophytes and chlorophytes varied dramatically among impoundments; total chlorophyll concentrations and standing crop values ranged from 8 to 483 mg·m−3 and 8.0 × 102 to 2.2 × 106 cells‐mL−1, respectively. Regression models fit to CAMS data provided reliable estimates for and produced accurate digital cartographs of total chlorophyll and carotenoid concentrations, phytoplankton standing crop, and turbidity. Although a model to effectively estimate in situ c‐phycocyanin concentrations was not identified, the lack of a suitable model may have resulted from variability of pigment extraction during quantification rather than failure of remotely sensed imagery to detect c‐phycocyanin. Models derived from imagery of impoundments directly beneath the aircraft sufficiently described in situ parameters in imagery of adjacent series of impoundments not directly below the aircraft. High‐resolution airborne remote sensing provides a means for monitoring local phytoplankton dynamics in temporal and spatial scales analogous to biotic and abiotic processes affecting such dynamics and necessary for applications to ecological research and fisheries or aquacultural management.

Gustatory Receptor Expression in the Labella and Tarsi of Aedes aegypti

The yellow-fever mosquito, Aedes aegypti, infects a growing number of people every year with dengue, yellow fever and chikungunya viruses. Contact chemoreception in mosquitoes influences a number of behaviors including host-selection, oviposition and feeding. While these behaviors are in many instances well documented, the molecular mechanisms mediating them are not well understood. Here we report the results of sequencing total messenger RNA in the labella and tarsi of both male and female Ae. aegypti to reveal Gustatory Receptor (GR) gene expression profiles in these major gustatory appendages. Gene expression levels in each tissue were verified by RT-qPCR. We discuss potential functions for the GRs revealed here by considering homologous GRs in other insects. Specific GRs provide molecular targets for modification of gustatory-mediated behaviors in this important disease vector.

Functional development of the octenol response in Aedes aegypti

Attraction of female Aedes aegypti mosquitoes to 1-octen-3-ol (octenol), CO2, lactic acid, or ammonia emitted by vertebrate hosts is not only contingent on the presence of odorants in the environment, but is also influenced by the insect’s physiological state. For anautogenous mosquito species, like A. aegypti, newly emerged adult females neither respond to host odors nor engage in blood-feeding; the bases for these behaviors are poorly understood. Here we investigated detection of two components of an attractant blend emitted by vertebrate hosts, octenol, and CO2, by female A. aegypti mosquitoes using electrophysiological, behavioral, and molecular approaches. An increase in sensitivity of octenol olfactory receptor neurons (ORNs) was correlated with an increase in odorant receptor gene (Or) expression and octenol-mediated attractive behavior from day 1 to day 6 post-emergence. While the sensitivity of octenol ORNs was maintained through day 10, behavioral responses to octenol decreased as did the ability of females to discriminate between octenol and octenol + CO2. Our results show differing age-related roles for the peripheral receptors for octenol and higher order neural processing in the behavior of female mosquitoes.

Detection of Bifidobacterium animalis subsp. lactis (Bb12) in the Intestine after Feeding of Sows and Their Piglets

ABSTRACT A real-time PCR method has been developed to distinguish Bifidobacterium animalis subspecies in the gastrointestinal tracts of pigs. Identification of a highly conserved single-copy tuf gene encoding the elongation factor Tu involved in bacterial protein biosynthesis was used as a marker to differentiate homologous Bifidobacterium animalis subsp. lactis (strain Bb12) from Bifidobacterium animalis subsp. animalis, as well as Bifidobacterium suis, Bifidobacterium breve, Bifidobacterium longum, several species of Lactobacillus, and Enterococcus faecium. Real-time PCR detection of serially diluted DNA extracted from a pure culture of Bb12 was linear for bacterial numbers ranging from 10 to 10,000 tuf gene copies per PCR (r2 = 0.99). Relative differences in Bb12 bacterial numbers in pigs fed daily with Bb12 were determined after detection of Bb12 tuf gene copies in DNA extracted from the intestinal contents. Piglets treated with Bb12 immediately after birth maintained a high level of Bb12 in their large intestines with continuous daily administration of Bb12. Piglets born to Bb12-treated sows during the last third of their gestation and also treated with Bb12 at birth (T/T group) had a higher number of Bb12 organisms per gram of intestinal contents compared to placebo-treated piglets born to placebo-treated sows (C/C group), Bb12-treated sows (T/C group), or piglets born to placebo sows but treated with Bb12 immediately after birth (C/T group). In addition, there was a significant increase in gene expression for Toll-like receptor 9 (TLR9) in piglets from the T/T group, with no change in TLR2 and TLR4. These findings suggest that the tuf gene represents a specific and functional marker for detecting Bifidobacterium animalis subsp. lactis strain Bb12 within the microbiota of the intestine.

Flavanol-Enriched Cocoa Powder Alters the Intestinal Microbiota, Tissue and Fluid Metabolite Profiles, and Intestinal Gene Expression in Pigs

BACKGROUND Consumption of cocoa-derived polyphenols has been associated with several health benefits; however, their effects on the intestinal microbiome and related features of host intestinal health are not adequately understood. OBJECTIVE The objective of this study was to determine the effects of eating flavanol-enriched cocoa powder on the composition of the gut microbiota, tissue metabolite profiles, and intestinal immune status. METHODS Male pigs (5 mo old, 28 kg mean body weight) were supplemented with 0, 2.5, 10, or 20 g flavanol-enriched cocoa powder/d for 27 d. Metabolites in serum, urine, the proximal colon contents, liver, and adipose tissue; bacterial abundance in the intestinal contents and feces; and intestinal tissue gene expression of inflammatory markers and Toll-like receptors (TLRs) were then determined. RESULTS O-methyl-epicatechin-glucuronide conjugates dose-dependently increased (P< 0.01) in the urine (35- to 204-fold), serum (6- to 186-fold), and adipose tissue (34- to 1144-fold) of pigs fed cocoa powder. The concentration of 3-hydroxyphenylpropionic acid isomers in urine decreased as the dose of cocoa powder fed to pigs increased (75-85%,P< 0.05). Compared with the unsupplemented pigs, the abundance ofLactobacillusspecies was greater in the feces (7-fold,P= 0.005) and that ofBifidobacteriumspecies was greater in the proximal colon contents (9-fold,P= 0.01) in pigs fed only 20 or 10 g cocoa powder/d, respectively. Moreover, consumption of cocoa powder reducedTLR9gene expression in ileal Peyers patches (67-80%,P< 0.05) and mesenteric lymph nodes (43-71%,P< 0.05) of pigs fed 2.5-20 g cocoa powder/d compared with pigs not supplemented with cocoa powder. CONCLUSION This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance ofLactobacillusandBifidobacteriumspecies and modulating markers of localized intestinal immunity.

The Recovery of Flavor Quality by Channel Catfish

Abstract Intensive production of channel catfish Ictalurus punctatus requires copious feeding. Nutrients from uneaten feeds and fish excreta contribute to the growth of microorganisms. Certain microbes that occur frequently in aquaculture systems produce the “muddy and earthy” off-flavor metabolites 2-methylisoborneol (MIB) and geosmin. Fish containing MIB or geosmin can exhibit an off-flavor that makes them unacceptable for harvest as food fish. Following the cessation of exposure to MIB or geosmin, fish depurate off-flavors. The minimum period required for fish to regain flavor quality is a critical concern for aquaculturists; scant information concerning this period prompted our investigation. Channel catfish were harvested from three commercial ponds, and fish from each pond were sorted into four size-classes (0.4–0.8 kg, 0.8–1.3 kg, 1.3–1.6 kg, and 1.6–2.3 kg) on 30 August (summer) and on 18 October (autumn) 1993. Each group of fish was transferred into individual 2,000-L fiberglass tanks, and each t...