Thermal tolerance does not explain the altitudinal segregation of lowland and alpine aquatic insects.

Elevation gradients provide powerful study systems for examining the influence of environmental filters in shaping species assemblages. High-mountain habitats host specific high-elevation assemblages, often comprising specialist species adapted to endure pronounced abiotic stress, while such harsh conditions prevent lowland species from colonizing or establishing. While thermal tolerance may drive the altitudinal segregation of ectotherms, its role in structuring aquatic insect communities remains poorly explored. This study investigates the role of thermal physiology in shaping the current distribution of high-mountain diving beetles from the Sierra Nevada Iberian mountain range and closely related lowland species. Cold tolerance of five species from each altitudinal zone was measured estimating the supercooling point (SCP), lower lethal temperature (LLT) and tolerance to ice enclosure, while heat tolerance was assessed from the heat coma temperature (HCT). Alpine species exhibited wider fundamental thermal niches than lowland species, likely associated with the broader range of climatic conditions in high-mountain areas. Cold tolerance did not seem to prevent lowland species from colonizing higher elevations, as most studied species were moderately freeze-tolerant. Therefore, fundamental thermal niches seem not to fully explain species segregation along elevation gradients, suggesting that other thermal tolerance traits, environmental factors, and biotic interactions may also play important roles.

Defining the radiation chemistry during liquid cell electron microscopy to enable visualization of nanomaterial growth and degradation dynamics.

We present a critical review of methods for defining the chemical environment during liquid cell electron microscopy investigation of electron beam induced nanomaterial growth and degradation. We draw from the radiation chemistry and liquid cell electron microscopy literature to present solution chemistry and electron beam-based methods for selecting the radiolysis products formed and their relative amount during electron irradiation of liquid media in a transmission electron microscope. We outline various methods for establishing net oxidizing or net reducing reaction environments and propose solvents with minimal overall production of radicals under the electron beam. Exemplary liquid cell electron microscopy experiments in the fields of nanoparticle nucleation, growth, and degradation along with recommendations for best practices and experimental parameters are reported. We expect this review will provide researchers with a useful toolkit for designing general chemistry and materials science liquid cell electron microscopy experiments by 'directing' the effect of the electron beam to understand fundamental mechanisms of dynamic nanoscale processes as well as minimizing radiation damage to samples.

Circadian rhythms, food timing and obesity.

It is known that our physiology changes throughout the day and that several physiological hormones display circadian rhythmicity. The alteration of this normal pattern is called chronodisruption (CD). In recent years, it has been demonstrated that CD is related to obesity. Although several factors may be causing CD, one important aspect to consider is the failure in our internal clock. Indeed, studies performed in mutant animals have demonstrated that mutations in clock genes are related to obesity. In human subjects, mutations are rare (<1 % of the population). Nevertheless, it is rather common to have genetic variations in one SNP, which underlie differences in our vulnerability to disease. Several SNP in clock genes are related to obesity and weight loss. Taking into account that genetics is behind CD, as has already been demonstrated in twins' models, the question is: Are we predestinated? We will see along these lines that nutrigenetics and epigenetics answer: 'No, we are not predestinated'. Through nutrigenetics we know that our behaviours may interact with our genes and may decrease the deleterious effect of one specific risk variant. From epigenetics the message is even more positive: it is demonstrated that by changing our behaviours we can change our genome. Herein, we propose modifying 'what, how, and when we eat' as an effective tool to decrease our genetic risk, and as a consequence to diminish CD and decrease obesity. This is a novel and very promising area in obesity prevention and treatment.

Visualizing surface plasmons with photons, photoelectrons, and electrons.

Both photons and electrons may be used to excite surface plasmon polaritons, the collective charge density fluctuations at the surface of metal nanostructures. By virtue of their nanoscopic and dissipative nature, a detailed characterization of surface plasmon (SP) eigenmodes in real space-time ultimately requires joint nanometer spatial and femtosecond temporal resolution. The latter realization has driven significant developments in the past few years, aimed at interrogating both localized and propagating SP modes. In this mini-review, we briefly highlight different techniques employed by our own groups to visualize the enhanced electric fields associated with SPs. Specifically, we discuss recent hyperspectral optical microscopy, tip-enhanced Raman nano-spectroscopy, nonlinear photoemission electron microscopy, as well as correlated scanning transmission electron microscopy-electron energy loss spectroscopy measurements targeting prototypical plasmonic nanostructures and constructs. Through selected practical examples from our own laboratories, we examine the information content in multidimensional images recorded by taking advantage of each of the aforementioned techniques. In effect, we illustrate how SPs can be visualized at the ultimate limits of space and time.

Microscopy of nanoparticulate dispersions.

We present a critical review of the common methods for determining the dispersion state of nanoparticulate samples particularly in liquid media, including the determination of particle size and morphology; particle size distributions and polydispersity and equilibrium particle structure and chemistry. We highlight the potential contributions of both scanning probe and electron microscopies in this analysis which is of benefit in understanding nanoparticulate formulations and their behaviour applied across a very wide range of technologies and industry sectors.

Meal timing affects glucose tolerance, substrate oxidation and circadian-related variables: A randomized, crossover trial.

BACKGROUND/OBJECTIVES: Timing of food intake associates with body weight regulation, insulin sensitivity and glucose tolerance. However, the mechanism is unknown. The aim of this study was to investigate the effects of changes in meal timing on energy-expenditure, glucose-tolerance and circadian-related variables. SUBJECTS/METHODS: Thirty-two women (aged 24±4 years and body mass index 22.9±2.6 kg m(-2)) completed two randomized, crossover protocols: one protocol (P1) including assessment of resting-energy expenditure (indirect-calorimetry) and glucose tolerance (mixed-meal test) (n=10), the other (P2) including circadian-related measurements based on profiles in salivary cortisol and wrist temperature (Twrist) (n=22). In each protocol, participants were provided with standardized meals (breakfast, lunch and dinner) during the two meal intervention weeks and were studied under two lunch-eating conditions: Early Eating (EE; lunch at 13:00) and Late Eating (LE; lunch 16:30). RESULTS: LE, as compared with EE, resulted in decreased pre-meal resting-energy expenditure (P=0.048), a lower pre-meal protein-corrected respiratory quotient (CRQ) and a changed post-meal profile of CRQ (P=0.019). These changes reflected a significantly lower pre-meal utilization of carbohydrates in LE versus EE (P=0.006). LE also increased glucose area under curve above baseline by 46%, demonstrating decreased glucose tolerance (P=0.002). Changes in the daily profile of cortisol and Twrist were also found with LE blunting the cortisol profile, with lower morning and afternoon values, and suppressing the postprandial Twrist peak (P<0.05). CONCLUSIONS: Eating late is associated with decreased resting-energy expenditure, decreased fasting carbohydrate oxidation, decreased glucose tolerance, blunted daily profile in free cortisol concentrations and decreased thermal effect of food on Twrist. These results may be implicated in the differential effects of meal timing on metabolic health.

Toward a chronobiological characterization of obesity and metabolic syndrome in clinical practice.

BACKGROUND & AIMS: To test several circadian rhythm variables in a female population to identify the best tool to assess chronodisruption in obesity and metabolic syndrome (MetS) to define a score to be used for chronodisruption characterization in clinical practice. METHODS: Anthropometric measurements and markers of circadian rhythms, such as sleep and feeding diary, Horne-Ostberg questionnaire, melatonin and cortisol measurements, and wrist temperature measurements, were determined. MetS variables were also analyzed. Study was conducted in 70 women. Data were subjected to factor analysis. Receiver operating characteristic curves were used as predictors of chronodisruption risk, and a score was calculated to classify the subjects of risk. RESULTS: Factor analysis showed that the first-factor grouped variables were related to the skin temperature measurement. Second factor consisted of variables related to salivary cortisol levels and obesity-related measurements. Third factor included variables related to sleep-wake cycle. Fourth factor referred to peripheral temperature variables and included the classification of subjects according to the Horne-Ostberg questionnaire. To obtain a final punctuation we performed the weighted mean of the first four factors. The final range was from 27 to 57, mean value of 42. Punctuation was defined as the "chronodisruption score." Women displaying higher chronodisruption scores had higher MetS risk. CONCLUSION: The study demonstrates that wrist temperature recordings, together with two questions of sleep onset and offset, and one morning salivary cortisol determination could be enough to characterize the chronobiology of obesity and MetS, a new chronodisruption score was developed.

Factors influencing quantitative liquid (scanning) transmission electron microscopy.

One of the experimental challenges in the study of nanomaterials in liquids in the (scanning) transmission electron microscope ((S)TEM) is gaining quantitative information. A successful experiment in the fluid stage will depend upon the ability to plan for sensitive factors such as the electron dose applied, imaging mode, acceleration voltage, beam-induced solution chemistry changes, and the specifics of solution reactivity. In this paper, we make use of a visual approach to show the extent of damage of different instrumental and experimental factors in liquid samples imaged in the (S)TEM. Previous results as well as new insights are presented to create an overview of beam-sample interactions identified for changing imaging and experimental conditions. This work establishes procedures to understand the effect of the electron beam on a solution, provides information to allow for a deliberate choice of the optimal experimental conditions to enable quantification, and identifies the experimental factors that require further analysis for achieving fully quantitative results in the liquid (S)TEM.

Timing of food intake predicts weight loss effectiveness.

BACKGROUND: There is emerging literature demonstrating a relationship between the timing of feeding and weight regulation in animals. However, whether the timing of food intake influences the success of a weight-loss diet in humans is unknown. OBJECTIVE: To evaluate the role of food timing in weight-loss effectiveness in a sample of 420 individuals who followed a 20-week weight-loss treatment. METHODS: Participants (49.5% female subjects; age (mean ± s.d.): 42 ± 11 years; BMI: 31.4 ± 5.4 kg m(-2)) were grouped in early eaters and late eaters, according to the timing of the main meal (lunch in this Mediterranean population). 51% of the subjects were early eaters and 49% were late eaters (lunch time before and after 1500 hours, respectively), energy intake and expenditure, appetite hormones, CLOCK genotype, sleep duration and chronotype were studied. RESULTS: Late lunch eaters lost less weight and displayed a slower weight-loss rate during the 20 weeks of treatment than early eaters (P=0.002). Surprisingly, energy intake, dietary composition, estimated energy expenditure, appetite hormones and sleep duration was similar between both groups. Nevertheless, late eaters were more evening types, had less energetic breakfasts and skipped breakfast more frequently that early eaters (all; P<0.05). CLOCK rs4580704 single nucleotide polymorphism (SNP) associated with the timing of the main meal (P=0.015) with a higher frequency of minor allele (C) carriers among the late eaters (P=0.041). Neither sleep duration, nor CLOCK SNPs or morning/evening chronotype was independently associated with weight loss (all; P>0.05). CONCLUSIONS: Eating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution - as is classically done - but also the timing of food.

Sexual dimorphism in clock genes expression in human adipose tissue.

BACKGROUND: This study was carried out to investigate whether sex-related differences exist in the adipocyte expression of clock genes from subcutaneous abdominal and visceral fat depots in severely obese patients. METHODS: We investigated 16 morbidly obese patients, eight men and eight women (mean age 45 ± 20 years; mean BMI 46 ± 6 kg/m(2)), undergoing laparoscopic gastric bypass surgery. Biopsies were taken as paired samples [subcutaneous and visceral adipose tissue (AT)] at the beginning of the surgical process at 11:00 h in the morning. Metabolic syndrome features such as waist circumference, plasma glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were also studied. The expression of clock genes (PER2, BMAL1, and CRY1) was measured by quantitative real-time PCR, Western blot, and immunohistochemical analysis. RESULTS: Gene expression was significantly higher in women than in men for the three genes studied in both ATs (P < 0.05). In visceral fat, these differences were more marked. (P < 0.001). Western blot analysis partially confirmed these results since statistical differences were observed for PER2 in both ATs and for CRY1 in subcutaneous adipose tissue. There were no differences in BMAL1 protein expression. Interestingly, clock gene expression level was correlated with LDL-C and HDL-C (P < 0.05). Moreover, we found significant associations with body fat mass in women and with age in men. CONCLUSIONS: Clock genes expression is sex dependent in human adipose tissue from morbidly obese subjects and correlates to a decreased in metabolic syndrome-related traits. These preliminary results make necessary to go deep into the knowledge of the molecular basis of the sexual dimorphism in chronobiology.

Site-specific circadian expression of leptin and its receptor in human adipose tissue / Expresión circadiana específica de la localización de leptina y su receptor en tejido adiposo humano

Introduction: Circadian variability of circulating leptin levels has been well established over the last decade. However, the circadian behavior of leptin in human adipose tissue remains unknown. This also applies to the soluble leptin receptor. Objective: We investigated the ex vivo circadian behavior of leptin and its receptor expression in human adiposetissue (AT). Subjects and methods: Visceral and subcutaneous abdominal AT biopsies (n = 6) were obtained from morbid obese women (BMI 40 kg/m2). Anthropometric variables and fasting plasma glucose, leptin, lipids and lipoprotein concentrations were determined. In order to investigate rhythmic expression pattern of leptin and its receptor, A Texplants were cultured during 24-h and gene expression was analyzed at the following times: 08:00, 14:00, 20:00, 02:00 h, using quantitative real-time PCR. Results: Leptin expression showed an oscillatory pattern that was consistent with circadian rhythm in cultured AT. Similar patterns were noted for the leptin receptor. Leptin showed its achrophase (maximum expression) during the night, which might be associated to a lower degree of fat accumulation and higher mobilization. When comparing both fat depots, visceral A Tanticipated its expression towards afternoon and evening hours. Interestingly, leptin plasma values were associated with decreased amplitude of LEP rhythm. This association was lost when adjusting for waist circumference. Conclusion: Circadian rhythmicity has been demonstrated in leptin and its receptor in human AT cultures ina site-specific manner. This new knowledge paves the way for a better understanding of the autocrine/paracrine role of leptin in human AT (AU)

Introducción: La variabilidad circadiana de los niveles de leptina circulante se ha establecido en la última década, pero actualmente se desconoce el comportamiento circadiano de leptina y su receptor en tejido adiposo (TA) humano. Objetivo: Investigar si existe un comportamiento circadiano en la expresión de leptina y su receptor en TA humano. Sujetos y métodos: Se obtuvieron biopsias de TA visceral y subcutáneo abdominal de mujeres (n = 6) obesas mórbidas (IMC 40 kg/m2). Se determinaron variables antropométricas y concentraciones plasmáticas en ayunas de glucosa, leptina, lípidos y lipoproteínas. Para investigar los patrones de expresión rítmica de los genes, se cultivaron explantes de TA durante 24-h y se analizó la expresión génica a diferentes horas: 08:00, 14:00, 20:00,02:00 h, usando PCR cuantitativa a tiempo real. Resultados: La leptina mostró un patrón oscilatorio de expresión comparable a un ritmo circadiano en TA cultivado. LEPR expresó patrones circadianos similares. Laleptina presentó su acrofase (máxima expresión) durante la noche, pudiendo asociarse al bajo grado de acumulación y elevada movilización de grasa. Cuando se comparan ambos depósitos grasos, en el TA visceral se anticipóla expresión hacia la tarde/noche. Fue interesante comprobar, cómo los valores plasmáticos de leptina se asociaron con una disminución de amplitud del ritmo de LEP, pero al ajustar para la circunferencia de cintura, dicha asociación desapareció. Conclusión: Demostramos ritmicidad circadiana deleptina y su receptor en TA humano, siendo específica de la localización adiposa. Estos descubrimientos preparan el terreno para una mejor comprensión del papel autocrino/paracrino de la leptina en el TA humano (AU)

Chemical solution approaches to YBa2Cu3O7_delta-Au nanocomposite superconducting thin films.

We explore the feasibility of preparing YBa2CU3O7-Au (YBCO-Au) nanocomposite thin films by chemical solution deposition (CSD). Two approaches were used: (i) A standard in-situ methodology where Au metallorganic salts are added into the precursor solution of YBCO trifluoroacetate (TFA) salts and (ii) a novel approach where stable colloidal solutions of preformed gold nanoparticles (5-15 nm) were homogeneously mixed with TFA-YBCO solutions. A detailed analysis of the microstructure of the films showed that in both cases, there is a strong tendency of gold nanoparticles to migrate to the film surface. However the kinetics of this migration evidences important differences and in the case of preformed nanoparticles their size remains unchanged (a few nanometers) whereas for the in-situ nanocomposites gold ripening leads to large particles (hundreds of nanometers). The grown YBCO-Au films showed good superconducting characteristics (J(c) 2 MA/cm2 at 77 K) but the absence of Au inclusions inside the YBCO matrix explains the fact that no enhancement of vortex pinning was observed.

Site-specific circadian expression of leptin and its receptor in human adipose tissue.

INTRODUCTION: Circadian variability of circulating leptin levels has been well established over the last decade. However, the circadian behavior of leptin in human adipose tissue remains unknown. This also applies to the soluble leptin receptor. OBJECTIVE: We investigated the ex vivo circadian behavior of leptin and its receptor expression in human adipose tissue (AT). SUBJECTS AND METHODS: Visceral and subcutaneous abdominal AT biopsies (n = 6) were obtained from morbid obese women (BMI ≥ 40 kg/m²). Anthropometric variables and fasting plasma glucose, leptin, lipids and lipoprotein concentrations were determined. In order to investigate rhythmic expression pattern of leptin and its receptor, AT explants were cultured during 24-h and gene expression was analyzed at the following times: 08:00, 14:00, 20:00, 02:00 h, using quantitative real-time PCR. RESULTS: Leptin expression showed an oscillatory pattern that was consistent with circadian rhythm in cultured AT. Similar patterns were noted for the leptin receptor. Leptin showed its achrophase (maximum expression) during the night, which might be associated to a lower degree of fat accumulation and higher mobilization. When comparing both fat depots, visceral AT anticipated its expression towards afternoon and evening hours. Interestingly, leptin plasma values were associated with decreased amplitude of LEP rhythm. This association was lost when adjusting for waist circumference. CONCLUSION: Circadian rhythmicity has been demonstrated in leptin and its receptor in human AT cultures in a site-specific manner. This new knowledge paves the way for a better understanding of the autocrine/paracrine role of leptin in human AT.

Circadian expression of adiponectin and its receptors in human adipose tissue.

Adiponectin is one of the most clinically relevant cytokines associated with obesity. However, circadian rhythmicity of adiponectin in human adipose tissue (AT) has not been analyzed. To assess whether the mRNA levels of adiponectin and its receptors (ADIPOR1 and ADIPOR2) might show daily circadian rhythms in visceral and sc fat explants obtained from morbid obese women, visceral and sc abdominal AT biopsies (n = 6) were obtained from morbidly obese women (body mass index >or=40 kg/m(2)). Anthropometric variables were measured and fasting plasma glucose, lipid, and lipoprotein concentrations were analyzed. To investigate rhythmic expression pattern, AT explants were cultured during 24 h, and gene expression was analyzed at the following times: 0800, 1400, 2000, and 0200 h, using quantitative real-time PCR. All genes investigated showed a circadian rhythmicity and oscillated accurately and independently of the suprachiasmatic nucleus in both AT explants (P < 0.05). Adiponectin gene expression fluctuated in the same phase as its receptors. Correlation analyses between the genetic circadian oscillation and components of the metabolic syndrome revealed that adiposity and abdominal obesity correlated with a decrease in adiponectin and adiponectin receptors ADIPOR1 and ADIPOR2 amplitude (P < 0.05). Visceral fat showed a trend toward a phase delay and dampening of the mRNA amplitude of adiponectin as compared with sc fat. The mRNA expression of adiponectin and its receptors showed 24-h rhythmicity in human AT from morbidly obese patients.

Parallel habitat-driven differences in the phylogeographical structure of two independent lineages of Mediterranean saline water beetles.

It has been hypothesized that species living in small lentic water bodies, because of the short-term geological persistence of their habitat, should show higher dispersal ability, with increased gene flow among populations and a less pronounced phylogeographical structure. Conversely, lotic species, living in more geologically stable habitats, should show reduced dispersal and an increased phylogeographical structure at the same geographical scales. In this work we tested the influence of habitat type in two groups of aquatic Coleoptera (Nebrioporus ceresyi and Ochthebius notabilis groups, families Dytiscidae and Hydraenidae respectively), each of them with closely related species typical of lotic and lentic saline Western Mediterranean water bodies. We used mitochondrial cox1 sequence data of 453 specimens of 77 populations through the range of nine species to compare a lotic vs. a lentic lineage in each of the two groups. Despite the differences in biology (predators vs. detritivorous) and evolutionary history, in both lotic lineages there was a higher proportion of nucleotide diversity among than within groups of populations, and a faster rate of accumulation of haplotype diversity (as measured by rarefaction curves) than in the lentic lineages. Similarly, lotic lineages had a higher absolute phylogenetic diversity, more remarkable considering their smaller absolute geographical ranges. By comparing closely related species, we were able to show the effect of contrasting habitat preferences in two different groups, in agreement with predictions derived from habitat stability.

Clock genes are implicated in the human metabolic syndrome.

BACKGROUND: Clock genes play a role in adipose tissue (AT) in animal experimental models. However, it remains to be elucidated whether these genes are expressed in human AT. OBJECTIVE: We investigated the expression of several clock genes, Bmal1, Per2 and Cry1, in human AT from visceral and subcutaneous abdominal depots. A second objective was to elucidate whether these clock genes expressions were related to the metabolic syndrome features. METHODS: Visceral and subcutaneous AT samples were obtained from morbid obese men (n=8), age: 42+/-13 years and body mass index>/=40 kg/m(2), undergoing laparoscopic surgery due to obesity. Biopsies were taken as paired samples at the beginning of the surgical process (1100 hour). Metabolic syndrome features such as waist circumference, plasma glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein (LDL) cholesterol were also studied. Homeostasis model assessment index of insulin resistance was also calculated. The expression of the different clock genes, hBmal1, hPer2 and hCry1, was determined by quantitative real-time PCR. RESULTS: Clock genes were expressed in both human AT depots. hBmal1 expression was significantly lower than hPer2 and hCry1 in both AT (P<0.001). All genes were highly correlated to one another in the subcutaneous fat, while no correlation was found between Bmal1 and Per2 in the visceral AT. Clock genes AT expression was associated with the metabolic syndrome parameters: hPer2 expression level from visceral depot was inversely correlated to waist circumference (P<0.01), while the three clock genes studied were significantly and negatively correlated to total cholesterol and LDL cholesterol (P<0.01). CONCLUSION: We have demonstrated for the first time in humans that clock genes are expressed in both subcutaneous and visceral fat. Their association with abdominal fat content and cardiovascular risk factors may be an indicator of the potential role of these clock genes in the metabolic syndrome disturbances.

The effects of an antioxidant-supplemented beverage on exercise-induced oxidative stress: results from a placebo-controlled double-blind study in cyclists.

The objective of this study was to test the effects of an antioxidant-supplemented beverage on exercise-induced oxidative stress in moderately trained cyclists. A double-blind study was conducted in moderately trained cyclists. They were randomly allocated to receive either an antioxidant (13 subjects) or a placebo (13 subjects) 15 min pre-exercise (30 ml.kg(-1)) and during a 90 min constant-load test (30 ml.kg(-1).15 min(-1)) on a bicycle ergometer at 70% VO2max The supplemented beverage contained black grape (81 g/l), raspberry (93 g/l) and red currant (39 g/l) concentrates, and its total antioxidant capacity, measured by the ABTS(.+) technique, was 0.41 mM Trolox. No significant difference from basal to post-exercise period was detected for plasma TBARS in either the placebo group or the group receiving the antioxidant supplemented beverage. Post-exercise carbonyls decreased by 29% in the group receiving antioxidants, and the pattern of change was significantly different between antioxidant and placebo conditions. The urinary excretion of 8-OHdG increased significantly by 21% in the placebo group. Again differences in the pre- to post-exercise change were significant between both conditions These results suggest that in moderately trained cyclists, antioxidant supplementation counters oxidative stress induced by a 90 min exercise at 70% VO2max.

[Meal replacement as a dietary therapy for weight control. Assessment in males and females with different degrees of obesity]. / Sustitutivos de una comida como terapia dietética en el control de peso. Evaluación en hombres y mujeres con diferentes grados de obesidad.

Obesity is a metabolic disorder characterized by an increase in the fat in adipose tissue above certain limits, manifested by morphological alterations and excess weight. This condition is one of the most significant epidemics of this century due to over-eating and the ease of access to food. On the other hand, the direct relationship between obesity and the greater risk of suffering cardiovascular disease, diabetes or cancer means that consumers are demanding products, whether medicines or foodstuffs, that will allow them to overcome this situation and improve both their physical appearance and their health. The goal of this project was to identify the efficacy and safety of a dietary product, a meal replacement, within the setting of a balanced hypocaloric diet established for weight loss. To this end, a total of 47 volunteers of both sexes between the ages of 23 and 58, all employees of the Hero España, S.A. company, took part in a test in which eleven of them acted as the "control group" and ate only the low-calorie diet while the rest formed a "problem group" and replaced one meal (with a minimum of 500 calories) with a 200-calorie meal replacement. Participants were subjected to anthropometric measurements, blood pressure testing and a blood chemistry analysis before and after the test period, as well as to weekly weight checks. Those individuals with the highest Body Mass Index showed a greater weight loss than those with a lower index. The volunteers did not note any hunger pangs until three hours after consumption of the meal replacement and the health-status parameters analyzed did not show any anomalous values. Therefore, it is concluded that the replacement product studied allows controlled weight loss over 3 weeks when accompanied by a balanced low-calorie diet and it also produces a sensation of fullness in those consuming it.

Sustitutivos de una comida como terapia dietética en el control de peso. Evaluación en hombres y mujeres con diferentes grados de obesidad / Meal replacement as a dietary therapy for weight control. Assessment in males and females with different degrees of obesity

La obesidad es una enfermedad metabólica caracterizada por un aumento de la grasa del tejido adiposo por encima de ciertos límites, que se manifiesta por alteraciones morfológicas y sobrepeso. Esta enfermedad constituye una de las epidemias más importantes de este siglo, debido a la sobrealimentación y facilidad de acceso a los alimentos. Por otro lado, la relación directa entre la obesidad y el mayor riesgo de padecer enfermedades cardiovasculares, diabetes o cáncer, hace que el consumidor demande productos, ya sean alimenticios o fármacos, que le permitan superar esa situación y mejorar tanto su aspecto físico como su estado de salud. El objetivo de este proyecto fue conocer la eficacia y seguridad de un producto dietético, un sustitutivo de una comida, dentro del conjunto de una dieta hipocalórica equilibrada establecida para el control de peso. Para ello, se contó con la participación de 47 voluntarios, hombres y mujeres de 23 a 58 años, todos ellos pertenecientes a la plantilla de la empresa Hero España, S. A. Once de ellos actuaron de "grupo de control" e ingirieron la dieta hipocalórica únicamente, mientras que el resto o "grupo problema" sustituyó una de las comidas del día (mínimo de 500 calorías) por un sustitutivo de unas 200 calorías. Se les realizaron medidas de antropometría, tensión arterial y bioquímica sanguínea antes y tras el período de estudio, así como control de peso semanal. Los individuos de mayor Índice de Masa Corporal mostraron una mayor reducción de peso que los de menor índice. Los voluntarios no apreciaron sensación de hambre hasta tres horas después de consumir el sustitutivo, y los parámetros analizados relativos al estado de salud no mos- traron ningún valor anómalo. Se concluye por tanto, que el producto sustitutivo estudiado permite una reducción de peso controlada durante 3 semanas, cuando se acompaña de una dieta hipocalórica equilibrada, y produce, además, sensación de saciedad en el consumidor (AU)

Obesity is a metabolic disorder characterized by an increase in the fat in adipose tissue above certain limits, manifested by morphological alterations and excess weight. This condition is one of the most significant epidemics of this century due to over-eating and the ease of access to food. On the other hand, the direct relationship between obesity and the greater risk of suffering cardiovascular disease, diabetes or cancer means that consumers are demanding products, whether medicines or foodstuffs, that will allow them to overcome this situation and improve both their physical appearance and their health. The goal of this project was to identify the efficacy and safety of a dietary product, a meal replacement, within the setting of a balanced hypocaloric diet established for weight loss. To this end, a total of 47 volunteers of both sexes between the ages of 23 and 58, all employees of the Hero España, S.A. company, took part in a test in which eleven of them acted as the "control group" and ate only the low-calorie diet while the rest formed a "problem group" and replaced one meal (with a minimum of 500 calories) with a 200-calorie meal replacement. Participants were subjected to anthropometric measurements, blood pressure testing and a blood chemistry analysis before and after the test period, as well as to weekly weight checks. Those individuals with the highest Body Mass Index showed a greater weight loss than those with a lower index. The volunteers did not note any hunger pangs until three hours after consumption of the meal replacement and the health-status parameters analyzed did not show any anomalous values. Therefore, it is concluded that the replacement product studied allows controlled weight loss over 3 weeks when accompanied by a balanced low-calorie diet and it also produces a sensation of fullness in those consuming it (AU)