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Relationship between Ketones, Ghrelin, and, Appetite on Isocaloric Diets with Varying Carbohydrate Quality and Amount: Results from a Randomized Controlled Trial in People with Obesity (CARBFUNC).
Sommersten, CH, Gjerde, ES, Laupsa-Borge, J, Andersen, AI, Lawrence-Archer, L, McCann, A, Hansson, P, Raza, GS, Herzig, KH, Lied, GA, et al
The Journal of nutrition. 2023;153(2):459-469
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Diet induced fat loss can result in an increase in appetite, contributing to weight loss regression and reduced diet adherence after successful weight loss. Certain diets such as those very high in fat and low in carbohydrates, which switches the body’s main fuel source to fat instead of sugar, have been shown to suppress feelings of hunger after weight loss. When this occurs it is known as ketosis and these diets may suppress a hormone, which is responsible for feelings of hunger, known as ghrelin. Diets which focus on the quality of the carbohydrate being consumed have also been shown to affect appetite. This randomised control trial of 193 individuals aimed to determine the effect of ketosis and the quality of carbohydrates on ghrelin and feelings of hunger. The results showed that ketosis during a low carbohydrate high fat diet was insufficient to decrease levels of the hunger hormone ghrelin and increased feelings of hunger. Carbohydrate quality also failed to decrease feelings of hunger or the hunger hormone ghrelin. It was concluded that regardless of the diet, fat loss resulted in feelings of hunger, which could not be supressed by a high-quality carbohydrate diet or a low carbohydrate high fat diet. This study could be used by health care professionals to understand that weight loss may be hindered by an increase in appetite. If this occurs, strategies to limit the hunger hormone ghrelin may be successful in maintaining weight loss.
Abstract
BACKGROUND Low-carbohydrate high-fat (LCHF) diets may suppress the increase in appetite otherwise seen after diet-induced fat loss. However, studies of diets without severe energy restriction are lacking, and the effects of carbohydrate quality relative to quantity have not been directly compared. OBJECTIVES To evaluated short- (3 mo) and long-term (12 mo) changes in fasting plasma concentrations of total ghrelin, β-hydroxybutyrate (βHB), and subjective feelings of appetite on 3 isocaloric eating patterns within a moderate caloric range (2000-2500 kcal/d) and with varying carbohydrate quality or quantity. METHODS We performed a randomized controlled trial of 193 adults with obesity, comparing eating patterns based on "acellular" carbohydrate sources (e.g., flour-based whole-grain products; comparator arm), "cellular" carbohydrate sources (minimally processed foods with intact cellular structures), or LCHF principles. Outcomes were compared by an intention-to-treat analysis using constrained linear mixed modeling. This trial was registered at clinicaltrials.gov as NCT03401970. RESULTS Of the 193 adults, 118 (61%) and 57 (30%) completed 3 and 12 mo of follow-up. Throughout the intervention, intakes of protein and energy were similar with all 3 eating patterns, with comparable reductions in body weight (5%-7%) and visceral fat volume (12%-17%) after 12 mo. After 3 mo, ghrelin increased significantly with the acellular (mean: 46 pg/mL; 95% CI: 11, 81) and cellular (mean: 54 pg/mL; 95% CI: 21, 88) diets but not with the LCHF diet (mean: 11 pg/mL; 95% CI: -16, 38). Although βHB increased significantly more with the LCHF diet than with the acellular diet after 3 m (mean: 0.16 mmol/L; 95% CI: 0.09, 0.24), this did not correspond to a significant group difference in ghrelin (unless the 2 high-carbohydrate groups were combined [mean: -39.6 pg/mL; 95% CI: -76, -3.3]). No significant between-group differences were seen in feelings of hunger. CONCLUSIONS Modestly energy-restricted isocaloric diets differing in carbohydrate cellularity and amount showed no significant differences in fasting total ghrelin or subjective hunger feelings. An increase in ketones with the LCHF diet to 0.3-0.4 mmol/L was insufficient to substantially curb increases in fasting ghrelin during fat loss.
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Effects of Plant-Based Diets on Weight Status: A Systematic Review.
Tran, E, Dale, HF, Jensen, C, Lied, GA
Diabetes, metabolic syndrome and obesity : targets and therapy. 2020;13:3433-3448
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Being overweight or obese is a huge risk factor for many detrimental conditions. It is estimated that around one-third of the world’s population will be overweight or obese by 2025. Hence there is a need to look at dietary strategies in the prevention and treatment of overweight and obesity. Plant-based diets have always existed, however interest in the topic has increased recently and more research is being done on the health-related effects of different plant-based diets. There are many reasons why someone might convert to a plant-based diet, possible health benefits such as weight management are among the most common. The purpose of this review was to evaluate intervention studies assessing the effects of different plant-based diets on body mass index and weight. The results suggest that plant-based diets may improve weight status in some patient groups. It should be noted that only one study out of the 19 included in the review had normal weight, clinically healthy participants. The study populations for the rest were overweight, obese or had type 2 diabetes. Future research should aim to include a representative study population and apply study diets without dietary restrictions.
Abstract
There is an increasing number of people who convert to a plant-based diet. The desire for health benefits, including weight management, is often a contributing factor behind this dietary choice. The purpose of this review was to evaluate intervention studies assessing the effects of different plant-based diets on body mass index and weight. A literature search was conducted in PubMed until December 2019. Twenty-two publications from 19 studies were included. The majority of them were randomized controlled trials comparing a low-fat vegan diet to an omnivore diet in participants with overweight, type 2 diabetes mellitus and/or cardiovascular disease. All studies reported weight reductions, of which seven revealed significant differences, and four revealed non-significant differences between the intervention and the control groups. The results suggest that plant-based diets may improve weight status in some patient groups. Due to restrictions in fat intake in many studies, followed by reduced energy intake, the effects of the different interventions differ depending on the specific plant-based diets investigated. Future research should aim to include a representative study population and apply study diets without dietary restrictions.
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Comparison of gut microbiota profile in celiac disease, non-celiac gluten sensitivity and irritable bowel syndrome: A systematic review.
Transeth, EL, Dale, HF, Lied, GA
The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology. 2020;31(11):735-745
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Dysbiosis refers to a disturbance in the quantity and composition of the gut microbiota, and this shift in the microbiota profile is associated with a variety of GI disorders including celiac disease (CD), irritable bowel syndrome (IBS) and non-celiac gluten sensitivity (NCGS). There is no current clinical distinction between IBS and NCGS although it is hypothesised the characteristics of gut microbiota of these clinical presentations may overlap. The aim of this review is to analyse the gut microbiota profile in these three diagnoses. Thirteen trials were included in this review and show the bacterial composition of the gut microbiota of patients with CD and IBS shared many similarities when compared to healthy controls, including an overall reduction in microbial abundance. There were fewer similarities between IBS and NCGS, in part due to the lack of existing literature. Based on these findings, the authors suggest the bacterial profiles of patients CD and IBS share certain disease-specific trends. While the current data is limited, the authors hope these suggested trends influence further research to examine the overlap between NCGS and IBS and distinguish differential diagnostic and treatment plans.
Abstract
Gut microbiota is vital for human health. Shifts in the microbial diversity can affect bacterial function, and dysbiosis is associated with a variety of gastrointestinal disorders, including celiac disease (CD) and irritable bowel syndrome (IBS). The distinction between IBS and non-celiac gluten sensitivity (NCGS) is unclear, and it is conceivable that the gut microbiota profile of these patients may overlap. To our knowledge, no existing literature has evaluated the microbial characteristics in CD, IBS, and NCGS. Hence, this systematic review aims to compare the gut microbiota profile in these three diagnoses. A literature search was conducted in PubMed (Medline) until April 2019. Studies investigating bacterial diversity in the gut of patients with CD, IBS, and NCGS were eligible. Inclusion criteria were observational studies and randomized controlled trials reporting bacterial profile at baseline. Ninety-one articles were identified, of which 13 trials were eligible for inclusion. Overall, the bacterial composition of the gut microbiota of patients with CD and those with IBS shared the many similarities. The microbial richness was correspondingly reduced in these patient-groups compared with healthy controls, but this was not reported for NCGS. Our findings suggest that the bacterial profiles of patients with IBS and CD share certain disease-specific trends. Fewer similarities were observed between the bacterial profiles of patients with IBS and NCGS. Notably, the data are limited; thus, no solid conclusions can be made on the basis of these findings alone. The suggested trends can be a valuable basis for further research.
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Effects of Plant-Based Diets on Outcomes Related to Glucose Metabolism: A Systematic Review.
Johannesen, CO, Dale, HF, Jensen, C, Lied, GA
Diabetes, metabolic syndrome and obesity : targets and therapy. 2020;13:2811-2822
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Research indicates that a reduction in the intake of animal products and an increase in plant-based foods have several positive health outcomes. The aim of this study was to evaluate the effect of a plant-based diet on outcomes related to glucose metabolism. This study is a systemic review of nine randomised controlled trials which focused on subjects with overweight/obesity, type 2 diabetes mellitus, or cardiovascular disease. Overall, the results of this study were inconsistent overall. Findings show that: - five of the nine studies (56%) showed that the plant-based intervention significantly improved markers of glycaemic control from baseline to end point. - four studies (44%) showed a significant improvement in markers of glycaemic control in the intervention group that differed from the control intervention. Additionally, they also did not reveal any significant improvements of a plant-based intervention on outcomes related to glucose metabolism. Authors outline that no clear conclusion regarding effects of different plant-based diets can be drawn based on the current findings.
Abstract
According to the rising prevalence of obesity and metabolic disorders leading to impaired glucose metabolism, effective strategies to prevent and/or delay the onset of disease are of great need. A plant-based diet has been suggested as an effective lifestyle change that may reduce the degree of obesity and improve outcomes related to glucose metabolism. This systematic review aimed to evaluate the effect of a plant-based diet on outcomes related to glucose metabolism. A literature search was conducted in the database PubMed until January 30, 2020. Randomized controlled trials investigating the effect of a plant-based dietary intervention on outcomes related to glucose metabolism in human subjects compared to an omnivorous diet were eligible for inclusion. Of 65 publications identified, nine trials on subjects with overweight/obesity, type 2 diabetes mellitus, or cardiovascular disease were included. Five studies reported that the plant-based intervention significantly improved markers of glycemic control from baseline to end point, of which four revealed a significant improvement in the intervention group compared to the control intervention. The remaining four studies did not observe a significant effect of a plant-based intervention on outcomes related to glucose metabolism. Our findings suggest that a shift to a plant-based diet may lead to favorable effects on glycemic control in individuals diagnosed with type 2 diabetes mellitus and/or obesity. The data were however somewhat conflicting, and the included trials reported results based on different intervention diets and study populations. Overall, no clear conclusions regarding effects of different plant-based diets can be drawn based on the current findings alone.