RESUMEN
The challenge of provision of a much wider range of foods of relatively low glycemic response than is currently available, especially in terms of cereal products, has been highlighted in recent years and this has particular relevance to bread consumption. Although there has been some transition to brown bread consumption, white bread remains a firm feature in the typical average western diet. This review first outlines the relationship between the glycemic impact of foods and health. What is important is that relatively small differences in glycemic potency of regularly consumed starch foods have been shown to have beneficial effects on health outcomes. Second, factors affecting glycemic response with particular application to white bread formulations are discussed. Novel ways of reformulating this highly favored carbohydrate staple, by using composite flours, with the aim of developing products of reduced glycemic response are highlighted in this review. Importantly, a new and significant focus on the role of unavailable carbohydrate in glycemic improvement is emerging. This has important application in increasing accessibility to health benefits by contributing to the prevention of and management of glucose intolerance, insulin resistance, and associated chronic disease to a wider range of consumers.
Asunto(s)
Glucemia/análisis , Pan/análisis , Alimentos , Índice Glucémico , Carbohidratos de la Dieta/administración & dosificación , Fibras de la Dieta/administración & dosificación , Grano Comestible , Harina/análisis , Alimentos Orgánicos , Promoción de la Salud , Humanos , Absorción Intestinal/fisiología , Modelos Biológicos , Almidón/administración & dosificaciónRESUMEN
BACKGROUND: Whether infants use suction or peristaltic tongue movements or a combination to extract milk during breast-feeding is controversial. The aims of this pilot study were 1] to evaluate the feasibility of using 3D ultrasound scanning to visualise infant tongue movements; and 2] to ascertain whether peristaltic tongue movements could be demonstrated during breast-feeding. METHODS: 15 healthy term infants, aged 2 weeks to 4 months were scanned during breast-feeding, using a real-time 3D ultrasound system, with a 7 MHz transducer placed sub-mentally. RESULTS: 1] The method proved feasible, with 72% of bi-plane datasets and 56% of real-time 3D datasets providing adequate coverage [>75%] of the infant tongue. 2] Peristaltic tongue movement was observed in 13 of 15 infants [83%] from real-time or reformatted truly mid-sagittal views under 3D guidance. CONCLUSIONS: This is the first study to demonstrate the feasibility of using 3D ultrasound to visualise infant tongue movements during breast-feeding. Peristaltic infant tongue movement was present in the majority of infants when the image plane was truly mid-sagittal but was not apparent if the image was slightly off the mid-sagittal plane. This should be considered in studies investigating the relative importance of vacuum and peristalsis for milk transfer.
Asunto(s)
Lactancia Materna , Movimiento , Lengua/fisiología , Femenino , Humanos , Imagenología Tridimensional , Lactante , Recién Nacido , Peristaltismo , Conducta en la Lactancia , Lengua/diagnóstico por imagen , UltrasonografíaRESUMEN
BACKGROUND: Mothers with preterm infants may need to express milk for considerable periods. Research to improve breast pump design has focused on compression stimuli, frequencies, and vacuums. OBJECTIVE: This study aimed to compare the effectiveness of 2 electric pumps: Medela Symphony (pump S) and a novel pump (Philips AVENT Twin electronic pump; pump A). Both offer flexibility of rate and suction; pump A also incorporates petal compression cushions. Primary outcomes were (1) milk weight expressed during 10-day study period and (2) weight of milk expressed in a 15-minute test. METHODS: Seventy-one mothers with preterm infants < 34 weeks were randomized. Mothers completed 10-day diaries including weight of milk expressed. Milk weight expressed during a single 15-minute test period and data on pumping mode, skin-to-skin contact, breastfeeding at infant discharge, and mothers' opinions of the pump were recorded. RESULTS: There was no significant difference in milk expressed during the first 10 days between groups. Pump S mothers expressed significantly more milk during a fixed 15-minute period. Mothers using pump A awarded higher scores for certain characteristics of the pump, notably location of control button and ease of use. Similar proportions of infants received breast milk at discharge, but pump A mothers were more likely to be directly breastfeeding (odds ratio, 4.27 [95% confidence interval, 1.29, 14.1]). CONCLUSION: The breast pumps showed similar effectiveness in terms of milk expression and maternal opinions. The finding that breast pump design may influence breastfeeding at infant discharge merits further investigation.
Asunto(s)
Extracción de Leche Materna/instrumentación , Unidades de Cuidado Intensivo Neonatal , Adulto , Lactancia Materna/estadística & datos numéricos , Investigación sobre la Eficacia Comparativa , Femenino , Humanos , Recién Nacido , Recien Nacido Prematuro , Análisis de Intención de Tratar , Evaluación de Resultado en la Atención de SaludRESUMEN
Eating in response to an increasingly obesogenic environment has been strongly implicated as a salient aspect of eating behaviour, arguably influenced by learning and experience. Interindividual differences in susceptibility to weight gain may be due, in part, to variability in response to environmental triggers. The phenomenon of food craving may also be an important factor influencing appetite control. The present study tested a model, in which food craving was hypothesised to be an intervening causal variable, on a causal pathway between responsivity to environmental cues and the development of obesity. One hundred and twenty four participants (aged 21-71 years, 83 females and 41 males) completed the study. Participants completed the Dutch eating behaviour questionnaire (DEBQ), measuring external eating (externality), emotional eating (emotionality) and restrained eating behaviour (restraint), and an adapted form of the food craving inventory (FCI), assessing cravings for carbohydrate, fats, sweets and fast food fats, in addition to total food cravings. Initial analysis showed positive correlations between FCI-tot and body mass index (BMI), FCI-fats and BMI and FCI-fast food fats and BMI in both men and women, and between FCI-carbohydrates and BMI in men only. Multiple regression analyses showed externality as the principal predictor of food craving, which was greater in males compared to females, but differential for different food groups between genders. Restrained eating and cravings for fats and fast food fats were negatively associated in women only. As predicted, total cravings, and cravings for fats and fast food foods mediated the positive association between external eating and BMI. It is concluded that appetitive response to external cues as an important risk factor in appetite control is mediated through cravings for particular food groups and is gender-dependent.
Asunto(s)
Apetito , Ingestión de Alimentos/psicología , Ingestión de Energía , Conducta Alimentaria/psicología , Inhibición Psicológica , Obesidad/psicología , Adulto , Anciano , Señales (Psicología) , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Ingestión de Alimentos/fisiología , Ambiente , Conducta Alimentaria/fisiología , Femenino , Preferencias Alimentarias/psicología , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Factores Sexuales , Encuestas y CuestionariosRESUMEN
The role of carbohydrates in health and disease has received a high profile in recent years, in particular the glycaemic index (GI) as a physiological classification of carbohydrate foods. A common carbohydrate source in the UK is white bread, which is considered to have a high GI value and low satiety value. In the present study, the possibility of favourably altering the GI of white bread by manipulating bread structure (loaf form) was investigated. In a randomised repeated-measures design, ten subjects were tested for glycaemic and satiety responses to four loaves of varying volume, but of consistent macronutrient content. Peak plasma glucose levels and GI values were shown to be significantly reduced by lowering loaf volume (P=0.007, P<0.001 respectively). In addition, a greater satiety index (SI) was seen with decreased loaf volume (P<0.001). In conclusion, the present study demonstrates that reducing the volume of white bread, which is generally considered to be high-GI and low-SI, can favourably alter metabolic and appetite responses. Relatively small differences in the GI of regularly consumed starch foods have been shown to have beneficial effects on health.
Asunto(s)
Glucemia/análisis , Pan , Carbohidratos de la Dieta/administración & dosificación , Respuesta de Saciedad/fisiología , Femenino , Vaciamiento Gástrico/fisiología , Índice Glucémico , Humanos , Masculino , Persona de Mediana Edad , Periodo PosprandialRESUMEN
Over 99% of modern animals are members of the evolutionary lineage Bilateria. The evolutionary success of Bilateria is credited partly to the origin of bilateral symmetry. Although animals of the phylum Cnidaria are not within the Bilateria, some representatives, such as the sea anemone Nematostella vectensis, exhibit bilateral symmetry. We show that Nematostella uses homologous genes to achieve bilateral symmetry: Multiple Hox genes are expressed in a staggered fashion along its primary body axis, and the transforming growth factor-beta gene decapentaplegic (dpp) is expressed in an asymmetric fashion about its secondary body axis. These data suggest that bilateral symmetry arose before the evolutionary split of Cnidaria and Bilateria.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Genes Homeobox , Anémonas de Mar/anatomía & histología , Anémonas de Mar/genética , Secuencia de Aminoácidos , Animales , Tipificación del Cuerpo , Endodermo/fisiología , Duplicación de Gen , Perfilación de la Expresión Génica , Genes , Hibridación in Situ , Larva/genética , Larva/crecimiento & desarrollo , Datos de Secuencia Molecular , Filogenia , Anémonas de Mar/embriología , Anémonas de Mar/crecimiento & desarrolloRESUMEN
Homeobox transcription factors are commonly involved in developmental regulation in diverse eukaryotes, including plants, animals, and fungi. The origin of novel homeobox genes is thought to have contributed to many evolutionary innovations in animals. We perform a molecular phylogenetic analysis of cnox2, the best studied homeobox gene from the phylum Cnidaria, a very ancient lineage of animals. Among three competing hypotheses, our analysis decisively favors the hypothesis that cnox2 is orthologous to the gsx gene of Bilateria, thereby establishing the existence of this specific homeobox gene in the eumetazoan stem lineage, some 650-900 million years ago. We assayed the expression of gsx in the planula larva and polyp of the sea anemone Nematostella vectensis using in situ hybridization and reverse transcriptase polymerase chain reaction. The gsx ortholog of Nematostella, known as anthox2, is expressed at high levels in the posterior planula and the corresponding "head" region of the polyp. It cannot be detected in the anterior planula or the corresponding "foot" region of the polyp. We have attempted to reconstruct the evolution of gsx spatiotemporal expression in cnidarians and bilaterians using a phylogenetic framework. Because of the surprisingly high degree of variability in gsx expression within the Cnidaria, it is currently not possible to infer unambiguously the ancestral cnidarian condition or the ancestral eumetazoan condition for gsx expression.