Efectos de la ingesta de los edulcorantes estevia y D-tagatosa sobre el metabolismo de la glucosa, ácido úrico y apetito-saciedad / Effects of stevia and D-tagatose sweeteners intake om glucose, uric acid metabolism and appetite-satiety

INTRODUCCIÓN: Si bien, los edulcorantes no nutritivos (ENN) estevia y D-tagatosa han sido reportados como seguros, han demostrado tener algunos efectos metabólicos tras su ingesta. OBJETIVO: Describir los efectos de la ingesta de estevia y D-tagatosa sobre el metabolismo de la glucosa y ácido úrico, y del apetito-saciedad, a partir de la evidencia disponible. MÉTODOS: Revisión descriptiva. Se realizó búsqueda en PubMed utilizando los siguientes términos y palabras clave: "stevia rebaudiana", "tagatose", "D-tagatose", "blood glucose", "insulin", "metabolic processes", "uric acid", "hyperuricemia", "appetite" o "satiety". El análisis de los estudios seleccionados fue discrecional. RESULTADOS: Existen estudios que demuestran efectos beneficiosos tras el consumo de estevia o D-tagatosa sobre el control glicémico, apetito y saciedad tanto en sujetos sanos como con alteraciones en el metabolismo de la glucosa. Por otra parte, un número importante de estudios que evalúan la ingesta de estevia reportan efectos nulos sobre dichos parámetros. En relación al ácido úrico, solo un estudio en sujetos con enfermedad renal crónica reporta aumento en la concentración de ácido úrico plasmático tras la ingesta de 500 mg/día de estevia. Pocos estudios han evaluado el efecto de la ingesta de D-tagatosa sobre uricemia, en sujetos sanos y diabéticos, reportando un aumento transitorio y significativo en los niveles de ácido úrico sérico, sin embargo, no se ha logrado demostrar un efecto hiperuricémico asociado. Es importante destacar que la metodología de los estudios revisados es heterogénea, especialmente en relación al tamaño muestral, tiempo, dosis y vía de adminitración del edulcorante. CONCLUSIÓN: La ingesta de estevia y D-tagatosa ha demostrado efectos beneficiosos sobre el metabolismo de la glucosa, el apetito y la saciedad. El efecto del consumo de D-tagatosa sobre ácido úrico sérico requiere mayor evidencia para demostrar su significancia clínica.

INTRODUCTION: No-nutritive sweeteners stevia and D-tagatose have been reported as safe according to their acceptable daily intake, however, they have been shown to have metabolic effects after their ingestion. OBJECTIVE: To describe the effects of stevia and D-tagatose intake on parameters associated to glucose, uric acid metabolism and on appetite-satiety, considering the available evidence. METHODS: Descriptive review. PubMed search was carried out to identify the totality of the published articles. The following terms and key words were used: "stevia rebaudiana", "tagatose", "D-tagatose", "blood glucose", "insulin", "metabolic processes", "uric acid", "hyperuricemia", "appetite" o "satiety". The analysis of the selected studies was discretionary. RESULTS: studies have shown beneficial effects of stevia and D-tagatose consumption on glycemic control, appetite and satiety in healthy subjects as well as subjects with impairment glucose metabolism. On the other hand, a significant number of studies evaluating estevia intake report null effects on these parameters. In relation to uric acid, only one study in subjects with chronic kidney disease reported an increase in plasmatic uric acid concentration after the intake of 500 mg/day of stevia. Several studies have evaluated the effect of D-tagatose intake on plasmatic uric acid, in healthy and diabetic subjects, reporting a transient and significant increase in serum uric acid levels, however, has not been able to demonstrate an associated hyperuricemic effect. It is important to highlight that the methodology of the studies reviewed is heterogeneous, especially in relation to sample size, dose administered, time and route of exposure to the sweetener. CONCLUSION: Stevia and D-tagatose intake has shown beneficial effects on glucose metabolism, appetite and satiety. The effects of the consumption of both sweeteners on uric acid require further study to demonstrate their clinic significance.

Serotonina e controle hipotalâmico da fome: uma revisão / Serotonin and hypothalamic control of hunger: a review

Este trabalho revisa a participação do sistema serotonérgico no controle da ingestão de alimentos e saciedade. É de grande interesse compreender a relevância desse sistema para o controle fisiológico do balanço energético e da obesidade. Mais de 35 anos de pesquisas sugerem que a serotonina (5-HT) desempenha um importante papel na saciedade. Assim, o sistema serotonérgico tem sido um alvo viável para o controle de peso. A 5-HT apresenta controle sobre a fome e a saciedade através de diversos receptores, com diferentes funções. O receptor 5-HT2C parece ser o mais importante na relação entre ingestão alimentar e balanço energético. Nesta revisão serão discutidos os mecanismos do sistema serotonérgico envolvidos no controle da ingestão de alimentos e saciedade.

This paper reviews involvement of the serotonergic system in the control of food intake and satiety. It is of great interest to understand the relevance of this system for physiological control of energy balance and obesity. Over 35 years of research suggest that serotonin (5-HT) plays an important role in satiety. Thus, the serotonergic system has been a viable target for weight control. The 5-HT has control over hunger and satiety through different receptors with distinct functions. The 5-HT2C receptor may be more important in the relationship between food intake and energy balance. This review will discuss the mechanisms of the serotonergic system involved in the control of food intake and satiety.

Effects of protein quality on appetite and energy metabolism in normal weight subjects / Efeitos da qualidade proteica no apetite e metabolismo energético de indivíduos eutróficos

OBJECTIVE: The purpose of this study was to compare the effects of consumption of different protein sources on food intake and energy expenditure in normal weight subjects. SUBJECTS AND METHODS: Breakfast preparations (casein, soy protein, whey protein or control) were ingested during seven consecutive days. Appetite, food intake, and energy expenditure were assessed. RESULTS: Casein consumption led to a lower energy intake than whey protein. There was lower energy intake on day 7 than on day 1 of the casein session. Soy protein preparations resulted in higher diet induced thermogenesis (DIT) than in control preparations. The respiratory quotient (RQ) obtained in the whey protein session was lower than the control and soy protein sessions. CONCLUSION: These results suggest that the consumption of different protein types leads to distinct effects on satiety (casein), DIT (soy protein), and/or RQ (whey protein).

OBJETIVO: O objetivo deste estudo foi comparar os efeitos do consumo de diferentes fontes proteicas na ingestão alimentar e gasto energético em indivíduos eutróficos. SUJEITOS E MÉTODOS: Preparações (caseína, proteína da soja, proteína do soro de leite ou controle) foram ingeridas no desjejum, durante sete dias consecutivos. RESULTADOS: A caseína resultou em menor ingestão calórica do que o soro de leite. Houve uma menor ingestão calórica no último dia da sessão da caseína em relação ao primeiro dia. Preparações contendo proteína da soja resultaram em maior termogênese induzida pela dieta (TID) em comparação às preparações controle. O cociente respiratório (CR) obtido na sessão do soro de leite foi menor que na sessão controle e da proteína da soja. CONCLUSÃO: Esses resultados sugerem que o consumo de diferentes tipos de proteínas resulta em efeitos distintos na saciedade (caseína), TID (proteína da soja) e/ou CR (proteína do soro).

Matching salt intake to physiological need in rats using foraging protocols

Several studies of the quantitative relationship between sodium need and sodium intake in rats are reviewed. Using acute diuretic treatment 24 h beforehand, intake matches need fairly accurately when intake is spread out in time by using a hypotonic solution of NaCl. In contrast, using a hypertonic solution, intake is typically double the need. Using the same diuretic treatment, although the natriuresis occurs within ~1 h, the appetite appears only slowly over 24 h. Increased plasma levels of aldosterone parallel the increased intake; however, treatment with metyrapone blocks the rise in aldosterone but has no effect on appetite. Satiation of sodium appetite was studied in rats using sodium loss induced by chronic diuretic treatment and daily salt consumption sessions. When a simulated foraging cost was imposed on NaCl access in the form of a progressive ratio lever press task, rats showed satiation for NaCl (break point) after consuming an amount close to their estimated deficit. The chronic diuretic regimen produced hypovolemia and large increases in plasma aldosterone concentration and renin activity. These parameters were reversed to or toward non-depleted control values at the time of behavioral satiation in the progressive ratio protocol. Satiation mechanisms for sodium appetite thus do appear to exist. However, they do not operate quantitatively when concentrated salt is available at no effort, but instead allow overconsumption. There are reasons to believe that such a bias toward overconsumption may have been beneficial over evolutionary time, but such biasing for salt and other commodities is maladaptive in a resource-rich environment.