Levels of hormones regulating appetite and energy homeostasis in response to a 1.5-Year combined lifestyle intervention for obesity.

Weight loss can induce changes in appetite-regulating hormone levels, possibly linked to increases in appetite and weight regain. However, hormonal changes vary across interventions. Here, we studied levels of appetite-regulating hormones during a combined lifestyle intervention (CLI: healthy diet, exercise and cognitive behavioral therapy).

Glucocorticoids, stress and eating: The mediating role of appetite-regulating hormones.

Disrupted hormonal appetite signaling plays a crucial role in obesity as it may lead to uncontrolled reward-related eating. Such disturbances can be induced not only by weight gain itself but also by glucocorticoid overexposure, for example, due to chronic stress, disease, or medication use. However, the exact pathways are just starting to be understood.

Effect of oat and soybean rich in distinct non-starch polysaccharides on fermentation, appetite regulation and fat accumulation in rat.

Consumption of non-starch polysaccharides (NSP) is associated with reduced risk of obesity. This study aimed to compare the effects of cereals (oats) and legumes (soybean), rich in different classes of NSP, on appetite regulation and fat accumulation in rats. Soy pectin fermented more efficient than cereal arabinoxylan in rats.

Effects of pectin on fermentation characteristics, carbohydrate utilization, and microbial community composition in the gastrointestinal tract of weaning pigs.

Scope: We aimed to investigate the effects of three different soluble pectins on the digestion of other consumed carbohydrates, and the consequent alterations of microbiota composition and SCFA levels in the intestine of pigs.

Methods And Results: Piglets were fed a low-methyl esterified pectin enriched diet (LMP), a high-methyl esterified pectin enriched diet (HMP), a hydrothermal treated soybean meal enriched diet (aSBM) or a control diet (CONT). LMP significantly decreased the ileal digestibility of starch resulting in more starch fermentation in the proximal colon.

Effects of pectin supplementation on the fermentation patterns of different structural carbohydrates in rats.

Scope: We aimed to investigate and compare the effects of four types of pectins on dietary fiber (DF) fermentation, microbiota composition, and short chain fatty acid (SCFA) production throughout the large intestine in rats.

Methods And Results: Male Wistar rats were given diets supplemented with or without 3% structurally different pectins for 7 weeks. Different fermentation patterns of pectins and different location of fermentation of pectin and diet arabinoxylans (AXs) in the large intestine were observed.

Diet-induced obesity resistance of adult female mice selectively bred for increased wheel-running behavior is reversed by single perinatal exposure to a high-energy diet.

Female mice from independently bred lines previously selected over 50 generations for increased voluntary wheel-running behavior (S1, S2) resist high energy (HE) diet-induced obesity (DIO) at adulthood, even without actual access to running wheels, as opposed to randomly bred controls (CON). We investigated whether adult S mice without wheels remain DIO-resistant when exposed - via the mother - to the HE diet during their perinatal stage (from 2 weeks prior to conception until weaning on post-natal day 21). While S1 and S2 females subjected to HE diet either perinatally or from weaning onwards (post-weaning) resisted increased adiposity at adulthood (as opposed to CON females), they lost this resistance when challenged with HE diet during these periods combined over one single cycle of breeding.

A low TSH profile predicts olanzapine-induced weight gain and relief by adjunctive topiramate in healthy male volunteers.

Second generation antipsychotics, like olanzapine (OLZ), have become the first line drug treatment for patients with schizophrenia. However, OLZ treatment is often associated with body weight (BW) gain and metabolic derangements. Therefore, the search for prospective markers for OLZ's negative side effects as well as adjunctive treatments to inhibit these has been of major interest.

Total energy expenditure assessed by salivary doubly labelled water analysis and its relevance for short-term energy balance in humans.

Rationale: The doubly labelled water (DLW) method is a stable isotopic technique for measuring total energy expenditure (TEE). Saliva is the easiest sampling fluid for assessing isotopic enrichments, but blood is considered superior because of its rapid exchange with body water. Therefore, we compared a large range of isotopic enrichments in saliva and blood, and related TEE in subjects with their ad libitum total energy intake (TEI).

High-saturated fat-sucrose feeding affects lactation energetics in control mice and mice selectively bred for high wheel-running behavior.

Feeding a diet high in fat and sucrose (HFS) during pregnancy and lactation is known to increase susceptibility to develop metabolic derangements later in life. A trait for increased behavioral activity may oppose these effects, since this would drain energy from milk produced to be made available to the offspring. To investigate these interactions, we assessed several components of behavioral energetics during lactation in control mice (C) and in mice of two lines selectively bred for high wheel-running activity (S1, S2) subjected to a HFS diet or a low-fat (LF) diet.

Forced and voluntary exercise counteract insulin resistance in rats: the role of coping style.

There are large individual differences in the success rates of exercise intervention programs aimed at the prevention and treatment of obesity-related disorders. In the present study, we tested the hypothesis that differences in coping style may impact the success rates of these intervention programs. We tested insulin responses before and after voluntary wheel running in both passive (insulin resistant) Roman Low Avoidance (RLA) and proactive (insulin sensitive) Roman High Avoidance (RHA) rats using intravenous glucose tolerance tests (IVGTTs).

Increased food intake and changes in metabolic hormones in response to chronic sleep restriction alternated with short periods of sleep allowance.

Rodent models for sleep restriction have good face validity when examining food intake and related regulatory metabolic hormones. However, in contrast to epidemiological studies in which sleep restriction is associated with body weight gain, sleep-restricted rats show a decrease in body weight. This difference with the human situation might be caused by the alternation between periods of sleep restriction and sleep allowance that often occur in real life.

Personality, a key factor in personalized medicine?

The incidence of health problems resulting from obesity is growing and obesity and its related diseases has become one of the main causes in death in industrialized societies. Environmental influences are crucial for the interactions between genetic, neurohormonal and metabolic factors that may be important in understanding individual differences in the development of obesity and metabolic diseases like type 2 diabetes. In particular the interactions between the personality of an individual and the environment play a key role in predicting the chance for successful treatment.

The lateral hypothalamus: a site for integration of nutrient and fluid balance.

This paper reviews seemingly obligatory relations between nutrient and fluid balance. A relatively novel neuronal pathway involving interplay between acetylcholine and the melanocortins, αMSH and AGRP in the arcuate nucleus (Arc) of the hypothalamus projecting to the lateral hypothalamus (LH) may bridge this gap. In the fasted condition, increased expression of MCH (due to muscarinic-3 receptor stimulation and low melanocortin tone) and neuronal release of MCH (via Orexin signaling) underlies a drive towards positive energy balance, increased B cell capacity to secrete insulin, and this is associated with optimal fluid homeostasis.

Individual variation in the (patho)physiology of energy balance.

There are large individual differences in the susceptibility for metabolic disorders such as obesity, the metabolic syndrome and type 2 diabetes. Unfortunately, most animal studies in this field ignore the importance of individual variation which limits the face validity of these studies for translation to the human situation. We have performed a series of studies that were particularly focused on the individual differences in the (patho)physiology of energy balance.

Pharmacological treatment of hyperinsulineamia in rats depends on coping style.

Passive and proactive coping styles are associated with marked differences in behavioral and neuroendocrine responses. Previous studies revealed that the passive individuals are more prone to hyperinsulinemia. Likewise, we hypothesize that different coping styles may require different drugs to treat this.

Coping style predicts the (in)sensitivity for developing hyperinsulinemia on a high fat diet in rats.

The aim of this study was to explore interactions between coping style and diet as risk factors for developing insulin resistance in rats. We hypothesized that rats characterized by a passive coping strategy are more susceptible for developing insulin resistance and visceral obesity than proactively coping rats, particularly on a high (45%) fat diet. This hypothesis was tested by comparing 1) insulin and glucose responses to an intravenous glucose tolerance test (IVGTT), and 2) body fat distribution, in two rat models for passive and proactive coping styles.

Neurobiology of hyperactivity and reward: agreeable restlessness in anorexia nervosa.

Restricted food intake is associated with increased physical activity, very likely an evolutionary advantage, initially both functional and rewarding. The hyperactivity of patients with anorexia nervosa, however, is a main problem for recovery. This seemingly paradoxical reward of hyperactivity in anorexia nervosa is one of the main aspects in our framework for the neurobiological changes that may underlie the development of the disorder.

Chronic sleep disturbance impairs glucose homeostasis in rats.

Epidemiological studies have shown an association between short or disrupted sleep and an increased risk for metabolic disorders. To assess a possible causal relationship, we examined the effects of experimental sleep disturbance on glucose regulation in Wistar rats under controlled laboratory conditions. Three groups of animals were used: a sleep restriction group (RS), a group subjected to moderate sleep disturbance without restriction of sleep time (DS), and a home cage control group.

Hepatic-portal oleic acid inhibits feeding more potently than hepatic-portal caprylic acid in rats.

In several human and animal studies, medium-chain triglycerides decreased food intake more than did long-chain triglycerides. It is possible that faster uptake and metabolism of medium-chain fatty acids in the liver is responsible for this difference. To test this hypothesis we compared the feeding effects of hepatic portal vein (HPV) infusion of the medium-chain fatty acid caprylic acid (CA) with those of the long-chain fatty acid oleic acid (OA).

Galanin in the PVN increases nutrient intake and changes peripheral hormone levels in the rat.

In self-selection feeding paradigms, rats display differential patterns of nutrient (protein, carbohydrate or fat) intake. Factors known to influence this selection include brain peptides as well as circadian parameters. In this series of experiments we investigated the role of PVN galanin in nutrient intake during the early and late dark periods in the rat.

AgRP(83-132) and SHU9119 differently affect activity-based anorexia.

Activity-based anorexia (ABA) mimics starvation and hyperactivity of anorexia nervosa patients in rats. Activation of the melanocortin (MC) system leads to hypophagia and increased energy expenditure in ad libitum fed rats. Therefore, activation of the MC system might underlie the development and propagation of ABA.

Effects of MCH and a MCH1-receptor antagonist on (palatable) food and water intake.

Melanin concentrating hormone (MCH) is a regulator of ingestive behavior, but several issues regarding its effects on specific components of ingestive behavior remain to be elucidated. Therefore, we injected, in the 3rd ventricle of male Wistar rats, saline, MCH (5 microg), MCH (5 mug) together with a MCH1-R antagonist (A, 10 microg) and the antagonist alone (A, 10 microg). Our results show that (1) central administration of MCH stimulates food intake (lab chow and medium high fat diet) and this can be blocked by a MCH1-R antagonist; (2) the MCH-induced increase in food intake is mediated through increased meal number, meal duration and meal size; (3) the MCH1-R antagonist is able to significantly reduce the intake of a highly palatable food (condensed sweet milk) and is more effective in blocking MCH-induced food intake when rats are fed a palatable medium high fat food; and (4) MCH stimulated water intake independently from and disproportionately to food intake.

Reduced anorexigenic efficacy of leptin, but not of the melanocortin receptor agonist melanotan-II, predicts diet-induced obesity in rats.

Leptin gains access to the central nervous system where it influences activity of neuronal networks involved in ingestive behavior, neuroendocrine activity, and metabolism. In particular, the brain melanocortin (MC) system is important in leptin signaling and maintenance of energy balance. Although leptin or MC receptor insensitivity has been proposed to be associated with obesity, the present study compared central leptin and MC receptor stimulation on some of the above-mentioned parameters and investigated whether these treatments predict proneness to diet-induced obesity (DIO) in outbred Wistar rats.

Comparison of the effects of three different (-)-hydroxycitric acid preparations on food intake in rats.

Background: Studies on the effects of (-)-hydroxycitric acid (HCA) in humans are controversial. As differences in the HCA preparations may contribute to this apparent discrepancy, the aim of the current study is to compare different HCA-containing preparations in adult Wistar rats.

Design: The effects of 3 different HCA-containing preparations (Regulator, Citrin K, Super CitriMax HCA-600-SXS, all used at an effective HCA dose of 150 and 300 mg/kg, administered intragastrically) on food intake and body weight were studied in adult male Wistar rats.

Ablation of capsaicin-sensitive afferent nerves affects insulin response during an intravenous glucose tolerance test.

We investigated the role of sensory nerves in glucose tolerance in conscious Wistar rats neonatally treated with neurotoxin capsaicin or vehicle. Intravenous glucose tolerance tests (IVGTT, 150, 300 and 450 mg in 30 min) were performed to measure glucose tolerance, and glucose, insulin and glucagon levels were measured. Higher glucose concentration resulted in a greater insulin response in both capsaicin- and vehicle-treated rats.