View clinical trials related to Diet Modification.
Filter by:This 12-week controlled diet and weight intervention study seeks to define the molecular pathways that link excess body weight to the development of insulin resistance (IR). Blood, adipose and stool are sampled at three timepoints; baseline, peak weight (4 weeks) and post weight loss to monitor changes in cellular processes. Additionally, direct insulin sensitivity testing, and radiological measurement of visceral fat and intrahepatic fat content is measured at three timepoints to correlate clinical indices with cellular changes.
In this study, we investigate the impact of insulin resistance on the acceleration of brain aging, and test whether increased neuron insulin resistance can be counteracted by utilization of alternate metabolic pathways (e.g., ketones rather than glucose). This study has three Arms, which together provide synergistic data. For all three Arms, subjects are tested in a within-subjects design that consists of 2-3 testing sessions, 1-14 days apart, and counter-balanced for order. During each session we measure the impact of fuel (glucose in one session, ketones in the other) on brain metabolism and associated functioning. For Arms 1-2, our primary experimental measure is functional magnetic resonance imaging (fMRI), which we will use to trace the self-organization of functional networks following changes in energy supply and demand. Arm 1 tests the impact of endogenous ketones produced by switching to a low carbohydrate diet, while Arm 2 tests the impact of exogenous ketones consumed as a nutritional supplement. For Arm 3, we use simultaneous magnetic resonance spectroscopy/positron-emission tomography (MR/PET) to quantify the impact of exogenous ketones on production of glutamate and GABA, key neurotransmitters. Subjects will be given the option to participate in more than one of the Arms, but doing so is not expected nor required. Prior to scans, subjects will receive a clinician-administered History and Physical (H&P), which includes vital signs, an oral glucose tolerance test (OGTT), and the comprehensive metabolic blood panel. These will be used to assess diabetes, kidney disease, and electrolytes. If subjects pass screening, they will be provided the option to participate in one or more Arms, which include neuroimaging. To provide a quantitative measure of time-varying metabolic activity throughout the scan, based upon quantitative models of glucose and ketone regulation, as well as to be able to implement safety stopping rules (see below), we will obtain pin-prick blood samples three times: prior to the scan, following consumption of the glucose or ketone drink, and following completion of the scan. To assess effects of increased metabolic demand, we measure brain response to cognitive load, transitioning from resting-state to spatial reasoning through a Tetris task. To assess effects of increased metabolic supply, we measure brain response to glucose or ketone bolus.
The PREDICT 3 study will build on previous research in over 2,000 individuals to further refine machine learning models that predict individual responses to foods, with the aim of advancing precision nutrition science and individualized dietary advice. The study incorporates both standardized and controlled dietary intervention, for the purpose of testing postprandial responses to specific mixed meals, in addition to a free-living period with a dietary record for measuring responses to a large variety of meals consumed in a realistic context, where the role of external factors (e.g. exercise, sleep, time of day) on postprandial responses may be determined. For the first time this PREDICT study is built on top of a commercial product which will allow access to a much larger group of participants who are already collecting large amounts of data through digital and biochemical devices that can contribute to science.
Low-carbohydrate diets (less than approximately 130 grams per day) are emerging as an efficacious treatment option with several studies supporting weight loss and remission of type 2 diabetes. Many physicians are now implementing this strategy but the time it takes to educate patients on nutrition is a barrier. The research team is working with physicians to develop a solution whereby the nutrition education and intervention is delivered via mobile/online technology (i.e., an app). This study will test whether it is feasible and efficacious for physicians to recommend this app to their patients with obesity and type 2 diabetes to help them lose weight and improve their condition.
The purpose of this study is to see how a diet that supplements fermented foods effects inflammation and quality of life in patients with mild to moderate Ulcerative Colitis (UC). There is a paucity of research and an enormous need for better understanding of diet and intestinal inflammation. Fermented food have been shown to positively influence inflammatory cytokines and intestinal microbial diversity in healthy volunteers.
Recent evidence suggests that hyperinsulinemia (i.e., elevated insulin levels) is the primary causative factor in obesity. Insulin promotes fat storage and prevents fat breakdown, suggesting that weight loss would be optimized if insulin levels are managed and kept low. Understanding how different foods impact insulin levels could therefore aid in personalized weight loss (or weight maintenance) advice. It has been shown that salivary insulin can track plasma insulin following different meals and can delineate between lean and obese people. Thus, it was suggested that salivary insulin could be a potential surrogate for plasma insulin. The purpose of this study is to measure fasting saliva insulin, and salivary insulin responses to a standardized meal tolerance test in individuals with different body mass index (BMI).
The aim of the study will be comparing the effectiveness of two diets: moderate in fat with a high proportion of monounsaturated fatty acids (MUFAs) - the Mediterranean diet (MED) and 2) the low in fat and high in dietary fiber contents the dietary approaches to stop hypertension diet (DASH) on weight maintenance and cardiovascular risks following a recent body weight reduction in centrally obese postmenopausal women. The tested diets will be given ad libitum manner. Moreover, adherence to both prescribed weight-loss maintenance diets will be also evaluated by the plasma concentration of alkylresorcinols (AR) as a possible whole grain wheat/rye dietary biomarker and by the analysis of fatty acids profile in erythrocyte membranes as a dietary biomarker of a fatty acids consumption. The participants of this study will be 150 non-smoking, postmenopausal women with central obesity, who wished to lose weight and have at least one other criterion of metabolic syndrome. The intervention will include 3 phases: Phase I (weeks 1-8), weight loss dietary intervention with 700 kcal/d energy deficit, Phase II (week 9-32), weight loss maintenance intervention for those participants losing ≥10% initial body weight the MED or the DASH diet will be offered in a random manner. The control group will receive oral dietary recommendations based on the Harvard model "Healthy Eating Plate". After this 32 weeks period will be finished, the participants will be discharged to the community with no contact by study personnel, until the 52-weeks follow-up period (Phase III).
The investigators are studying the impact of insulin resistance on the acceleration of brain aging and testing whether increased neuron insulin resistance can be counteracted by utilization of alternate metabolic pathways (e.g., ketones rather than glucose). This study has three Arms, which together provide synergistic data. For all three Arms, subjects are tested in a within-subjects design that consists of 2-3 testing sessions, 1-14 days apart, and counter-balanced for order. Impact of fuel (glucose in one session, ketones in the other) on brain metabolism and associated functioning is measured during each session. For Arms 1-2, the primary experimental measure is functional magnetic resonance imaging (fMRI), which is used to trace the self-organization of functional networks following changes in energy supply and demand. Arm 1 tests the impact of endogenous ketones produced by switching to a low carbohydrate diet, while Arm 2 tests the impact of exogenous ketones consumed as a nutritional supplement. For Arm 3, simultaneous magnetic resonance spectroscopy/positron-emission tomography (MR/PET) is used to quantify the impact of exogenous ketones on production of glutamate and GABA, key neurotransmitters. Subjects will be given the option to participate in more than one of the Arms, but doing so is not expected nor required. Prior to scans, subjects will receive a clinician-administered History and Physical (H&P), which includes vital signs, an oral glucose tolerance test (OGTT), and the comprehensive metabolic blood panel. These will be used to assess diabetes, kidney disease, and electrolytes. If subjects pass screening, they will be provided the option to participate in one or more Arms, which include neuroimaging. To provide a quantitative measure of time-varying metabolic activity throughout the scan, based upon quantitative models of glucose and ketone regulation, as well as to be able to implement safety stopping rules (see below), the investigators will obtain pin-prick blood samples three times: prior to the scan, following consumption of the glucose or ketone drink, and following completion of the scan. To assess effects of increased metabolic demand, the investigators measure brain response to cognitive load, transitioning from resting-state to spatial reasoning through a spatial navigation video task. To assess effects of increased metabolic supply, the investigators measure brain response to glucose or ketone bolus.
Shift work is associated with a higher risk of the development of cardiometabolic syndrome (CMtS) than in people working only during the day. One of the factors predisposing to the development of the CMtS in shift workers is an inappropriate composition of their diet. It was observed that the shift workers diet is characterized by a higher intake of saturated fatty acids (SFA) and a lower consumption of unsaturated fatty acids. One potential way to reduce the risk of CMtS in this study group seems to be a modification of their everyday diet by excluding the products of animal origin (e.g. butter) with simultaneously including vegetable oils (i.e. canola oil). The aim of the study is to evaluate the effect of replacement in the everyday diet of saturated fats (butter) with unsaturated fats (canola oil-based spread and canola oil added to main meals) in centrally obese shift workers on changes in body weight and body composition parameters as well as on changes in CMtS markers.
To evaluate the therapeutic efficacy and metabolic impact of a low energy diet (LED) in people with familial partial lipodystrophy and diabetes. Participants will be provided with a LED (total diet replacement) for 12 weeks, before the introduction of a stepped food transition. Metabolic effects will continue to be assessed for 1 year. In order to better understand why this intervention changes insulin sensitivity, we will also collect adipose and muscle tissue samples at baseline and 12 weeks into the intervention in participants willing to have these procedures performed. These samples will be used for histological, metabolite, gene expression and protein expression analyses.