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Cannabis effects on lipoproteins.
Lazarte, J, Hegele, RA
Current opinion in lipidology. 2019;(2):140-146
Abstract
PURPOSE OF REVIEW The endocannabinoid system affects several physiological functions. A family of endocannabinoid receptors is susceptible to cannabis constituents. Cannabis is widely used in our society and following its recent legalization in Canada, we focus on how exposure to cannabis and pharmacologic cannabinoid receptor type 1 (CB1) inhibition affect lipoprotein levels. RECENT FINDINGS Several groups have reported that exposure to cannabis does not increase weight despite the marked increase in caloric intake. In observational studies, the effect of smoked cannabis exposure on plasma lipids is variable. Some studies in specific patient populations with longer exposure to cannabis seemed to identify slightly more favorable lipoprotein profiles in the exposed group. Several larger controlled clinical trials using orally administered rimonabant, a CB1 receptor antagonist, have consistently shown relative improvements in weight and plasma levels of triglyceride and high-density lipoprotein cholesterol among patients receiving the treatment. SUMMARY The widely variable findings on the relationship of cannabis in various forms with plasma lipids preclude any definitive conclusions. Cannabis has complex effects on the cardiovascular system and its effects on lipid profile must be considered in this overall context. Further properly controlled research is required to better understand this topic.
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Homeostatic and neurocognitive control of energy intake in response to exercise in pediatric obesity: a psychobiological framework.
Thivel, D, Finlayson, G, Blundell, JE
Obesity reviews : an official journal of the International Association for the Study of Obesity. 2019;(2):316-324
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While energy intake and energy expenditure have long been studied independently, the alarming progression of obesity has led to a more integrative approach to energy balance considering their potential interactions. Although the available literature concerned with the effect of chronic and acute exercise on energy intake and appetite control in adults is considerable, these questions remain less explored among children and adolescents. Based on the search of four databases (Medline, Embase, PsycINFO and Cochrane Library; articles published until May 2018), the objective of this review is to summarize and discuss the effect of acute and chronic physical exercise on energy intake and appetite control in children and adolescents with obesity, and to identify the physiological and neurocognitive signals and pathways involved. Evidence suggested that acute intensive exercise has the potential to reduce subsequent energy intake in children and adolescents with obesity but not healthy weight, through both peripheral (mainly gastro-peptides) and neurocognitive (neural responses to food cues) pathways. The nutritional responses to chronic physical activity remain less clear and require further consideration, especially from an anti-obesity perspective.
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Metabolic adaptations during negative energy balance and their potential impact on appetite and food intake.
Casanova, N, Beaulieu, K, Finlayson, G, Hopkins, M
The Proceedings of the Nutrition Society. 2019;(3):279-289
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This review examines the metabolic adaptations that occur in response to negative energy balance and their potential putative or functional impact on appetite and food intake. Sustained negative energy balance will result in weight loss, with body composition changes similar for different dietary interventions if total energy and protein intake are equated. During periods of underfeeding, compensatory metabolic and behavioural responses occur that attenuate the prescribed energy deficit. While losses of metabolically active tissue during energy deficit result in reduced energy expenditure, an additional down-regulation in expenditure has been noted that cannot be explained by changes in body tissue (e.g. adaptive thermogenesis). Sustained negative energy balance is also associated with an increase in orexigenic drive and changes in appetite-related peptides during weight loss that may act as cues for increased hunger and food intake. It has also been suggested that losses of fat-free mass (FFM) could also act as an orexigenic signal during weight loss, but more data are needed to support these findings and the signalling pathways linking FFM and energy intake remain unclear. Taken together, these metabolic and behavioural responses to weight loss point to a highly complex and dynamic energy balance system in which perturbations to individual components can cause co-ordinated and inter-related compensatory responses elsewhere. The strength of these compensatory responses is individually subtle, and early identification of this variability may help identify individuals that respond well or poorly to an intervention.
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An Evolutionary Perspective on Why Food Overconsumption Impairs Cognition.
Mattson, MP
Trends in cognitive sciences. 2019;(3):200-212
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Brain structures and neuronal networks that mediate spatial navigation, decision-making, sociality, and creativity evolved, in part, to enable success in food acquisition. Here, I discuss evidence suggesting that the reason that overconsumption of energy-rich foods negatively impacts cognition is that signaling pathways that evolved to respond adaptively to food scarcity are relatively disengaged in the setting of continuous food availability. Obesity impairs cognition and increases the risk for some psychiatric disorders and dementias. Moreover, maternal and paternal obesity predispose offspring to poor cognitive outcomes by epigenetic molecular mechanisms. Neural signaling pathways that evolved to bolster cognition in settings of food insecurity can be stimulated by intermittent fasting and exercise to support the cognitive health of current and future generations.
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Effects of sleep restriction on metabolism-related parameters in healthy adults: A comprehensive review and meta-analysis of randomized controlled trials.
Zhu, B, Shi, C, Park, CG, Zhao, X, Reutrakul, S
Sleep medicine reviews. 2019;:18-30
Abstract
This review aimed to provide a comprehensive examination of the effect of sleep restriction on metabolism-related parameters by synthesizing the emerging, best evidence. A systematic search was conducted in six electronic databases from inception to January 2018. We identified 41 randomized controlled trials using sleep restriction intervention. The outcomes included: subjective hunger, appetite-regulating hormones, changes in brain activity, energy intake and expenditure, weight change, insulin sensitivity or resistance. Sleep restriction resulted in a significant increase in subjective hunger on a 100 mm scale (mean difference = 13.4, p < 0.001). Participants consumed 252.8 more kcal/d (p = 0.011) under sleep restriction than under normal sleep. Partial sleep restriction resulted in a 0.34 kg weight gain (p = 0.003). Sleep restriction also decreased insulin sensitivity (standardized mean difference = -0.70, p < 0.01). Significant changes in brain activity in response to food stimuli were observed under sleep restriction, particularly regions related to cognitive control and reward. Overall, we did not find strong evidence supporting the significant impact of sleep restriction on mean leptin or ghrelin levels or energy expenditure. Findings from this review enhanced our knowledge about the detrimental effects of sleep restriction on metabolism and provided novel directions in preventing metabolic diseases including obesity and diabetes.
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Interaction between genes involved in energy intake regulation and diet in obesity.
Crovesy, L, Rosado, EL
Nutrition (Burbank, Los Angeles County, Calif.). 2019;:110547
Abstract
Obesity is a multifactorial, complex, and public health problem worldwide. Interaction between genes and environment as associated with diet may predispose an individual to obesity. In this sense, nutrigenetics appears to be a strategy that can improve understanding of the gene-diet interaction. The aim of this literature review was to summarize data from studies of genes involved in the regulation of energy intake (melanocortin 4 receptor [MC4R], fat mass and obesity-associated [FTO], ghrelin [GHRL], leptin [LEP], and cholecystokinin [CCK]) and diet interaction in obesity. The presence of polymorphisms in MC4R, FTO, leptin, and the respective receptor appear to be associated with higher energy and total lipid consumption. Polymorphisms in FTO, leptin, and leptin receptor are also related to increased intake of saturated fatty acids. Individuals with the MC4R, FTO, and ghrelin polymorphisms, who submitted themselves for weight loss intervention, appeared to achieve weight loss similar to individuals without polymorphisms in these genes. Additionally, protein seems to interact with these genes, which increases or decreases appetite, or to drive or lessen body weight recovery. Additionally, polymorphisms in these genes were found to be associated with inappropriate eating behaviors, such as increased consumption of sweets and snacks, consumption of large food portions, desire to eat, and eating associated with emotional issues. Preliminary data has supported the gene-diet interaction in determining weight loss and gain in individuals with polymorphisms in the genes involved in energy intake. Despite the advent of nutrigenetics in obesity, it is still too early to define the dietary management for weight loss based on the presence or absence of obesity polymorphisms.
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Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting.
Anton, SD, Moehl, K, Donahoo, WT, Marosi, K, Lee, SA, Mainous, AG, Leeuwenburgh, C, Mattson, MP
Obesity (Silver Spring, Md.). 2018;(2):254-268
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Abstract
OBJECTIVE Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. This review is focused on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch: the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). RESULTS AND CONCLUSIONS Emerging findings suggest that the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty acid-derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. Moreover, IF regimens also induce the coordinated activation of signaling pathways that optimize physiological function, enhance performance, and slow aging and disease processes. Future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and of the magnitude of negative energy balance during the fasting period.
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How much does reduced food intake contribute to cancer-associated weight loss?
Martin, L, Kubrak, C
Current opinion in supportive and palliative care. 2018;(4):410-419
Abstract
PURPOSE OF REVIEW An international consensus group defined cancer cachexia as a syndrome of involuntary weight loss, characterized by loss of skeletal muscle (with or without fat loss), which is driven by a variable combination of reduced food intake and altered metabolism.This review presents recent studies that evaluated the contribution of reduced food intake to cancer-associated weight loss. RECENT FINDINGS Four studies examined food intake in relation to weight loss. Heterogeneity among studies rendered aggregation and interpretation of results challenging. Despite these limitations, reduced food intake had consistent significant, independent associations with weight loss. However, reduced food intake did not explain all the variation in weight loss; and limited data suggests factors related to alterations in metabolism (e.g. increased resting energy expenditure, systemic inflammation) are also contributing to weight loss. SUMMARY Reduced food intake is a significant contributor to cancer-associated weight loss. Understanding the magnitude of the association between food intake and weight loss may improve when it is possible to account for alterations in metabolism. Efforts to align clinical assessments of food intake to reduce heterogeneity are needed.
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Dietary Modifications and Lipid Accumulation Product Are Associated with Systolic and Diastolic Blood Pressures in the Women's Health Trial: Feasibility Study in Minority Populations.
Bhargava, A
Current hypertension reports. 2018;(6):50
Abstract
PURPOSE OF REVIEW Approximately 65% of adults over 60 years in the USA are hypertensive. Poor dietary habits and sedentary lifestyles are fueling the hypertension epidemic. The effects of higher intakes of fruits and vegetables and whole-grain products on systolic and diastolic blood pressures were analyzed using data at baseline, 6 months, and 12 months on 349 and 573 subjects, respectively, in the control and intervention groups of the Women's Health Trial: Feasibility Study in Minority Populations. RECENT FINDINGS Models for systolic and diastolic blood pressures have been estimated using cross-sectional and longitudinal data in different settings. However, it is important to estimate comprehensive dynamic random effects models that take into account inter-relationships between systolic and diastolic blood pressures as well as the effects of dietary intakes and biomarkers for making robust inferences. There were significantly greater reductions (P < 0.05) between baseline and 12 months in systolic and diastolic blood pressures in the intervention group. Second, ratios of α-tocopherol to energy intakes were negatively and significantly associated with systolic and diastolic blood pressures in the intervention group. Third, the lipid accumulation product was positively associated with systolic and diastolic blood pressures in the control and intervention groups. The estimated coefficients of diastolic and systolic blood pressure variables in the respective models for systolic and diastolic blood pressures showed that combining the two measures as pulse pressure can lead to misleading inferences. Overall, dietary interventions promoting higher consumption of fruits and vegetables and whole-grain products can help lower blood pressures of women in the USA.
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Modalities for assessing the nutritional status in patients with diabetes and cancer.
Clemente, G, Gallo, M, Giorgini, M, ,
Diabetes research and clinical practice. 2018;:162-172
Abstract
Epidemiological data have shown that an increased body mass index (BMI) is associated with a higher risk of various cancers, especially in obese diabetic patients. However, oncologic patients often present nutritional alterations that can worsen their prognosis. The aim of this review is to propose the use of cheaper and easy to use tools to assess the nutritional status of patients with cancer with altered glucose metabolism. Based on a literature review, we propose anthropometric measures to classify the degree of malnutrition. Moreover, the Karnofsky Performance Status (KPS) and the Eastern Cooperative Oncology Group's performance index (ECOG) are useful to assess the functional status of the body; the achievement of nutritional needs can be analysed with the PG-SGA questionnaire, while the quality of life can be investigated using the DTSQ, SF36, EQ-5D questionnaires and the Edmonton Symptom Assessment System. Pre-albumin dosage and lymphocyte count are proposed as nutritional parameters. The degree of hydration can be evaluated through the Bio-Impedance Test (BIA), and energy intake through the dairy food diary, which considers the type of nutrition and the consistency of the meals. It is possible to use a score for each tool used, which is useful to plan an adequate nutritional intervention.