Gul Tiryaki-Sonmez, Serife Vatansever, Burcin Olcucu and Brad Schoenfeld
Obesity, a disorder of body composition, is defined by a relative or absolute excess of body fat. In general adult population, obesity has been associated with a diverse array of adverse health outcomes, including major causes of death such as cancer, diabetes, cardiovascular disease, as well as functional impairment from problems such as osteoarthritis and sleep apnea. Ghrelin is a newly discovered peptide hormone which plays an important role in obesity. It is a powerful, endogenous orexigenic peptide and has a crucial function in appetite regulation, as well as short – and long-term energy homeostasis. In the presence of increased obesity, decreased physical activity, and high food consumption, the relationship between exercise, appetite, food intake and ghrelin levels has important implications. In this review, we discuss the effect of acute and chronic exercise performance on appetite, food intake and ghrelin and their relationships.
Introduction. The current study aimed to assess profiles of peptide YY and ghrelin, visual analog scales (VAS) for hunger and satiety, and ad libitum intake in obese and non-obese women.
Methods. This open-label non-randomized interventional study involved obese (BMI ≥ 25–35 kg/m2) and non-obese (BMI 18.5–23.0 kg/m2) women subjects. Levels of peptide YY and ghrelin were determined by radioimmunoassay and enzyme-linked immunosorbent assay (ELISA), respectively, while the degrees of hunger and satiety were measured using visual analog scale (VAS) questionnaires. The results were compared in fasting condition and in 15, 60, 120, and 180 minutes after breakfast with balance composition formulation. This study also compared the ad libitum intake within 4 hours after breakfast.
Results. As compared to the non-obese group, the obese group have significantly lower levels of peptide YY in fasting, and in 15, 60, 120, and 180 minutes post-prandial, and smaller AUC (Area Under the Curve) of fasting peptide YY. Furthermore, the obese group showed significantly higher ad libitum intake. The obese group also have lower levels of ghrelin and lower VAS for hunger and higher in VAS for satiety as compared to the non-obese group.
Conclusions. There were significant differences in peptide YY level, 4 hours after breakfast ad libitum intake, ghrelin level, and VAS for hunger and satiety, between obese group and non-obese one.
Background and aims: The present study aimed to assess the relative validity of the Romanian version of a food frequency questionnaire (FFQ) in evaluating habitual dietary intake.
Material and methods: We used an FFQ that comprised questions on 90 beverage and food items from Nurses Health Questionnaire. The linguistic interchangeability between translation and original questions of the FFQ was assessed in 50 bilingual adults. Also, the FFQ was validated against the 24-h recall diary in 85 participants from ORO study enrolled in Cluj County.
Results: The Spearman correlation coefficients between the Romanian and English versions of the FFQ ranged between 0.614 and 1.000, with the majority having values >0.900 (p <0.05 for all). Caloric and nutrient intake estimated from FFQ was significantly correlated with that derived from 24-h dietary recall (correlation coefficients 0.243 to 0.339; p-values <0.05). >70% of the participants were classified in the same or adjacent quartiles of energy and nutrient consumption showing a good agreement between FFQ and 24-h dietary recall. Tested FFQ questionnaire had a good internal consistency with Cronbach’s alpha coefficients of 0.931 and 0.949, respectively.
Conclusion: Tested FFQ had an acceptable relative validity and can be used to estimate caloric and macronutrient intake.
The renin-angiotensin system plays a crucial role in the regulation of cardiovascular function and maintenance of water-electrolyte balance. The two major receptor types of the system, AT1 and AT2, have different, often opposite effects on these functions.
AIM: To elucidate the impact of long term treatment with selective angiotensin receptor antagonists and an agonist on water-salt balance in normotensive Wistar and spontaneously hypertensive rats (SHRs).
MATERIALS AND METHODS: 12-week-old male Wistar rats and SHRs were individually housed in metabolic cages and 24-h food and water intake and urine and electrolyte excretion were measured. Urinary sodium (UNa), potassium (UK) and chlorine (UCl) were determined by a flame photometer. Losartan, a selective AT1 receptor antagonist, was administered in the Wistar rats and SHRs at a dose of 10 mg/kg/day subcutaneously (sc). Wistar rats were also given the AT2 receptor antagonist, PD123319, subcutaneously at a dose of 10 mg/kg/ day. CGP 42112A, an AT2 receptor agonist, was administered intracerebroventricularly in Wistar rats at a dose of 12 μg/rat/day. The drugs were infused continuously for 14 days through osmotic minipumps.
RESULTS: Losartan selectively increased sodium excretion in both rat strains and decreased weight gain in SHRs. PD123319 increased potassium excretion and decreased weight gain in Wistar rats. CGP 42112A increased food and water intake, urine output and UNa+ and UK+ excretion and decreased weight gain in normotensive Wistar rats.
CONCLUSIONS: Chronic treatment with selective angiotensin receptor ligands modifies water- salt balance in rats through changes both in renal excretory function and ingestive behaviors.
Nazli Khajehnasiri, Homayoun Khazali, Farzam Sheikhzadeh and Mahnaz Ghowsi
Objective. The hypothalamic arcuate nucleus proopiomelanocortin (POMC) and neuropeptide Y (NPY) circuitries are involved in the inhibition and stimulation of the appetite, respectively. The aim of this study was to investigate the effects of one-month lasting high-intensity exercise on the POMC mRNA and NPY mRNA expression in the above-mentioned brain structure and appetite and food intake levels.
Methods. Fourteen male Wistar rats (250±50 g) were used and kept in the well-controlled conditions (22±2 °C, 50±5% humidity, and 12 h dark/light cycle) with food and water ad libitum. The rats were divided into two groups (n=7): 1) control group (C, these rats served as controls) and 2) exercised group (RIE, these rats performed a high-intensity exercise for one month (5 days per week) 40 min daily with speed 35 m/min. The total exercise time was 60 min. The body weight and food intake were recorded continuously during the experiments.
Results. The results showed relative mRNA expression of POMC and NPY estimated in the hypothalamic arcuate nucleus. There were no significant differences in the NPY and POMC mRNAs expression levels and food intake between C and RIE groups.
Conclusions. The present data indicate that one-month regular intensive exercise did not alter the levels of NPY and POMC mRNAs expression (as two important factors in the regulation of appetite) in the hypothalamic arcuate nucleus and food intake suggesting that this type of exercise itself is not an appropriate procedure for the body weight reduction.
Rudīte Lagzdiņa, Leons Blumfelds, Maija Rumaka and Līga Aberberga-Augškalne
Eating habits with uniform food preferences and increased energy intake can contribute to increased gain of body fat. An adequate diet, body self-evaluation, and recognition of unhealthy nutrition patterns should promote appropriate corrective actions. The aim of the present study was to determine whether energy intake, food diversity and corrective modification of body mass differed among student groups with low, normal and high body fat percentage. The study involved 737 (158 male and 579 female) students of the Rîga Stradiòð University (age 18-49 years). Dietary behaviour was determined using self-administered questionnaire. Body fat percentage was determined with a Tanita MC-180 bioimpedance analyser. Fluid and food intake, as well as physical activity before the test was restricted. The results showed that 15% of students in the low, 38% in the normal and 62% in the high body fat percentage groups considered that they eat too much. In the low, normal and high body fat percentage groups of students, 27%, 37% and 42%, respectively, agreed that they do restrict food intake. There were no significant differences in normalised energy intake and food diversity indexes between these student groups. Students in the high body fat percentage group more frequently admitted eating to much, and their corrective behaviour was associated more with reduced amounts of eaten food rather than minimisation of energy intake and increased food diversity. In all fat percentage groups, female students more frequently admitted that they eat too much and more often tended to restrict food intake than male students.
Morteza Zendehdel, Yasaman Moosadoost, Reza Masoumi, Behnam Rostami, Mohammad Hossein Shahir and Shahin Hassanpour
Evidence from animal studies suggests that endogenous nitric oxide and dopamine (DA) have a regulatory role in the rewarding system, but their interaction(s) have not been studied in avian species. In this study, 4 experiments were performed to determine the effects of central administration of L-arginine (nitric oxide precursor; 200 nmol), NG-nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor; 100 nmol), amphetamine (an indirect DA agonist; 125 pmol) and DA (40 pmol) on feeding behavior in neonatal layer-type chickens (each experiment included 4 groups, n=12 birds in each group). Prior to the initiation of the treatments, birds were fasted for 3 hours (FD3). In experiment 1, chickens received intracerebroventricular (ICV) injection of saline, L-NAME (100 nmol), amphetamine (125 pmol), and combination of L-NAME + amphetamine. In experiment 2, chickens received the ICV injection of saline, L-arginine (200 nmol), amphetamine (125 pmol) and their combination. In experiment 3, chickens received ICV injection of saline, L-arginine (200 nmol), DA (40 pmol) and L-arginine + DA. In experiment 4, chickens received ICV injection of saline, L-NAME (100 nmol), DA (40 pmol) and L-NAME + DA. Thereafter, the cumulative food intake (on the basis of metabolic body weight) was recorded until 2-h post injection. The results showed that ICV injection of amphetamine or DA significantly decreased food intake (P<0.05). Also, co-administration of L-NAME + amphetamine attenuated the hypophagic effect of amphetamine (P<0.05), while combined administration of L-NAME and DA had no effect on DA-induced hypophagia. Additionally, the hypophagic effect of amphetamine was significantly amplified by L-arginine (P<0.05), but the combination of L-arginine and DA did not alter feeding behavior which was induced by DA. These results suggest an interaction between DAergic and nitrergic systems via a presynaptic mechanism on food intake regulation in layer-type chicken.
The maintenance of the body weight at a stable level is a major determinant in keeping the higher animals and mammals survive. Th e body weight depends on the balance between the energy intake and energy expenditure. Increased food intake over the energy expenditure of prolonged time period results in an obesity. Th e obesity has become an important worldwide health problem, even at low levels. The obesity has an evil effect on the health and is associated with a shorter life expectancy. A complex of central and peripheral physiological signals is involved in the control of the food intake. Centrally, the food intake is controlled by the hypothalamus, the brainstem, and endocannabinoids and peripherally by the satiety and adiposity signals. Comprehension of the signals that control food intake and energy balance may open a new therapeutic approaches directed against the obesity and its associated complications, as is the insulin resistance and others. In conclusion, the present review summarizes the current knowledge about the complex system of the peripheral and central regulatory mechanisms of food intake and their potential therapeutic implications in the treatment of obesity.
Simone Buttu, Giulia Atzori, Francesco Palmas and Robert Gwiazda
A study of the diet of the Great Cormorant Phalacrocorax carbo sinensis (fish species and size) in (1) different seasons (years), (2) breeding stages (incubation and chick rearing), and (3) breeding areas (center and edge) in the colony in the Dzierżno-Duże Reservoir (southern Poland) was carried out. Overall, 147 pellets of the Great Cormorant were analysed. The low values of the indexes of Levin (Bi) and Shannon (H’) showed a limited trophic spectrum in the diet of the Great Cormorant. Roach (Rutilus rutilus) with a percentage index of relative importance (%IRI) of 62.89, perch (Perca fluviatilis) (%IRI = 22.63) and carp (Cyprinus carpio) (%IRI = 10.43), were the most common prey. Evident changes in the diet between 2003 and 2014, with less roach and more perch and ruffe in 2014 were found. They could be probably related to changes in the fish community. Differences in the food of cormorants between breeding stages reflected dietary requirements of the chicks. During the breeding season younger chicks require feeding with smaller fish than older chicks. The proportion of fish species found in the cormorant diet differed between the edge and the centre of the colony. We concluded that the impact of Great Cormorants on native fish assemblages may be dependent on the location within the colony, development state of the chicks and season, not just fish availability.
Obesity and its consequent complications such as hypertension and metabolic syndrome are increasing in incidence in almost all countries. Insulin resistance is common in obesity. Renin– angiotensin system (RAS) is an important target in the treatment of hypertension and drugs that act on RAS improve insulin resistance and decrease the incidence of type 2 diabetes mellitus, explaining the close association between hypertension and type 2 diabetes mellitus. RAS influences food intake by modulating the hypothalamic expression of neuropeptide Y and orexins via AMPK dephosphorylation. Estrogen reduces appetite by its action on the brain in a way similar to leptin, an anorexigenic action that seems to be mediated via hypothalamic pro-opiomelanocortin (POMC) neurons in the arcuate nucleus and synaptic plasticity in the arcuate nucleus similar to leptin. Estrogen stimulates lipoxin A4, a potent vasodilator and platelet anti-aggregator. Since both RAS and estrogen act on the hypothalamic neuropeptides and regulate food intake and obesity, it is likely that RAS modulates LXA4 synthesis. Thus, it is proposed that Angiotensin-II receptor blockers and angiotensin-converting enzymes and angiotensin-II antagonists may have the ability to augment LXA4 synthesis and thus bring about their beneficial actions.