64 Clinical Trials for Various Conditions
Design of this study is to collect data and review Principal Investigators standard operating procedures on allergy testing and changes made to their specific SOP.
This randomized, controlled trial aims to elucidate the mechanisms by which a plant-based dietary intervention causes weight loss. Using a low-fat, plant-based diet for 16 weeks, along with an untreated control for comparison, the study will measure changes in body weight, body composition, intramyocellular and/or intrahepatocellular lipid, and changes in association to body weight.
The goal is to identify food sensitivity in patients and assess whether the avoidance of the reaction-inducing foods via an 'elimination diet' leads to improvement in patient symptoms and overall well-being.
Background: Increases in obesity, diabetes, and some metabolic disorders may be linked to how much processed foods people eat. Researchers want to learn more about how processed foods affect metabolic health. Objective: To learn about how a processed versus unprocessed diet affects the body. Eligibility: Men ages 18-50 with stable weight and risk factors for diabetes Design: Participants will be screened over 3 visits. Screening includes: * Medical history and physical exam * Heart and blood tests * Psychiatric questions * Questions about eating, sleeping, and economic status * Riding a stationary bike * Trying a sample meal Between screenings, participants will eat prepared meals. They will wear an accelerometer to measure physical activity. They will write down what foods they eat and monitor their weight. Participants will have two 4-week stays in the clinic. They will: * Eat a special diet * Have activity and weight monitored * Drink water and collect urine samples to measure how many calories they are burning * Have resting energy expenditure measured with a clear hood over the head * Have a scan to measure body fat and bone density using low-dose x-rays * Have a scan on a table that slides into a metal cylinder in a strong magnetic field. They will get earplugs for the loud noises. * Have an ultrasound test to measure blood vessels * Have insulin and glucose infused into an arm vein. Blood will be taken over 10 hours through a plastic tube in the wrist. This will happen 4 times. * Spend multiple 24-hour periods in a room that measures oxygen used and carbon dioxide produced. * Give blood, urine and stool samples * Answer questionnaires and do computer tasks
Food products derived from cereal grains constitute a major part of the daily diet of many Americans . For example, a typical Chinese American eats rice about 9.5 times a week on an average. However, most of these foods are derived from refined grain. During the refining process grains are stripped of their bran and germ which results in depletion of several biologically active constituents including fiber, anti-oxidants, phytoestrogens and minerals. From observational studies there is evidence for a protective effect of whole-grain foods with regard to the development of type 2 diabetes. More recently, higher intake of whole grains was also associated with decreases in insulin resistance - a risk factor related to the development of type 2 diabetes. In this randomized study the investigators plan to replicate this beneficial effect of improving insulin sensitivity in patients with pre-diabetes and go a step further by exploring the potential mechanisms by which this benefit may occur. The investigators will assess the effect of consuming a whole-grain-rich diet on levels of advanced glycation endproducts (AGE), RAGE (receptor for AGE) and markers of inflammation and oxidative stress - all of which have been shown to play an important role in the pathogenesis of diabetes mellitus. The investigators will also look for correlations between the levels of these markers with insulin sensitivity to identify potential mechanisms of pathogenesis.
This study will examine the effects of a dietary fiber on insulin sensitivity in overweight and obese women. The fiber will be added to snack foods and women will consume the foods for four weeks. In one four-week period, 15 g of fiber will be added, and 30 g will added in another period. In a third period, no fiber will be added to the snack foods. Insulin senstivity will be measured at the end of each treatment period.
The overall objective of the Dietary Protein and Insulin Sensitivity Study is to test the hypothesis that increased protein in a diet with reduced carbohydrate (35% energy) can ameliorate insulin resistance in the absence of weight loss, and that this effect is independent of saturated fat content. Moreover, we will test whether such diets result in beneficial changes in total LDL cholesterol, small, dense LDL, and HDL cholesterol that are also independent of saturated fat intake.
This study will screen patients with cerebellar ataxia to check for antibodies that indicate allergy to gluten (wheat protein) and will study the effect of a gluten-free diet in patients with these antibodies. Patients with cerebellar ataxia have problems with coordination, resulting in "clumsiness" and unsteadiness of posture and walking. There are many known causes of cerebellar ataxia, but in many patients the cause is unknown and there are no available treatments. Cerebellar ataxia has been recognized as a complication of celiac disease, a syndrome characterized by sensitivity to gluten. Recognizing gluten sensitivity in patients with cerebellar ataxia would be important for two reasons: it would be one of the rare causes of the disease that are potentially treatable, and it would identify patients at risk for developing gastrointestinal cancers, particularly intestinal lymphoma. Patients with cerebellar ataxia of known or unknown cause and normal healthy volunteers of any age are eligible for this study. All participants will have a medical history, physical examination, blood drawn (30 milliliters, or 2 tablespoons) to check for celiac disease antibodies, and possibly other lab tests. This completes the participation of normal volunteers. All patients will have magnetic resonance imaging (MRI) of the brain. This diagnostic tool uses a strong magnetic field and radio waves instead of X-rays to show structural and chemical changes in tissues. During the scanning, the patient lies on a table in a narrow cylinder containing a magnetic field. He or she can speak with a staff member via an intercom system at all times during the procedure. Scanning times vary from 20 minutes to 2 hours. Patients who have celiac disease antibodies will have an upper gastrointestinal (GI) endoscopy intestinal biopsy. For this procedure, a flexible tube is inserted into the mouth and down the throat into the stomach and duodenum (the upper part of the small intestine), where a small tissue sample is taken for microscopic examination. Patients with these antibodies will be put on a gluten-free diet and will be followed at NIH every 3 months for 12 months. On the first visit, patients will have their ataxia evaluated using NINDS's ataxia scale and will meet with a dietitian for instructions for a gluten-free diet. On the second through fifth visits (after 3, 6, 9 and 12 months, respectively, on the gluten-free diet), patients will have their ataxia evaluated, speak with a dietitian to assess their nutritional status, weight, and compliance with the diet, and provide a blood sample for celiac disease antibody testing. At the completion of the study, patients may choose to continue or stop the gluten-free diet. If the ataxia assessments show improvement, patients will be advised to continue the gluten-free diet permanently.
The goal of this 16-week clinical trial is to assess the health benefits of a low-fat vegan diet on insulin sensitivity and glycemic control in type 2 diabetes. Participants will receive at no cost, study-related weekly nutrition education classes and one-on-one consultation with a registered dietitian.
The purpose of this study is to compare the effects of a low-fat, plant-based dietary intervention and a portion-controlled dietary intervention (compliant with current American Diabetes Association (ADA) guidelines) on changes in intramyocellular and hepatocellular lipid content in adults with type 2 diabetes. Changes in insulin sensitivity and glycemic control will also be assessed in this study. The study duration is 44 weeks.
Physical inactivity results in reductions in glucose tolerance and less sensitivity to insulin. If this inactivity lasts long enough it can result in insulin resistance and type 2 diabetes. A high protein diet can reduce elevated glucose levels in individuals with type 2 diabetes. Thus the investigators are interested in establishing if during a period of inactivity if a diet modification can minimize the glucose changes normally observed with inactivity. The objective of this project is to determine if short-term high protein (HP) feeding protects against the changes in glucose levels normally observed with physical inactivity. The investigators will also examine measures of blood vessel function, blood lipid and blood pressure. Twelve subjects will complete two 10 day study periods of reduced physical activity and will be studied before and after each of these study periods. For their testing subjects will have the following measurements: postprandial glucose responses to a mixed meal, 24 h free living blood pressure control during acute physical inactivity, blood lipids, changes in body composition, changes in circadian rhythm using skin temperature (ibutton), measurement of aerobic capacity (VO2 max), blood vessel responsiveness (flow mediated dilation -FMD) and changes in free living glucose levels (continuous glucose monitoring system (CGMS). Subjects will complete two conditions (high protein -HP vs normal protein - NP diets) in a randomized cross-over design. In the inactive phase subjects will reduce there steps to \<5,000 steps/d while consuming either a HP or NP diet. Completion of the study will take 8-10 weeks.
The investigators will measure plasma concentrations of the hormones insulin and testosterone as well as measures of insulin sensitivity in women with overweight or obesity who have insulin resistance (IR). Women who meet these criteria that also have elevated total or free testosterone will be eligible to participate in the diet intervention. The dietary intervention is designed to produce a 5% reduction in starting body weight to test whether weight loss will acutely lower fasting insulin and testosterone concentrations.
Despite strong evidence that tight control of blood sugar reduces the risk of diabetes complications, most people with type 1 diabetes do not achieve recommended blood sugar targets. This randomized controlled trial will test whether a very-low- carbohydrate ketogenic diet can effectively and safely improve blood sugar control in adults with type 1 diabetes.
Participants with IBS are skin patch tested (no needles) to 80 different foods and food additives, compounded for patch testing, in search of food allergies. The testing requires 3 office visits within a 4 or 5 day period. The patches are taped to the back at Visit #. At Visit #2 48 hours later, the patches are removed from the skin and the outside border of each patch is marked with a felt tip marker. At Visit #3 (final visit) 1 or 2 days later, the patch test reading is performed by the doctor-investigator. An allergy is identified as a small red mark where the food was in contact with the skin for 48 hours. Those participants found to have food allergies are then placed on an avoidance diet (no calorie restriction) for 16 weeks where they either avoid eating the food(s) to which they are allergic (the \"true\" avoidance diet) or food(s) to which the testing did not show an allergy (this is called the \"sham\" avoidance diet). There is a 50/50 chance of going on either avoidance diet. The avoidance diet is assigned in such a way that neither the participant or the doctor-investigator knows which diet is being followed. After the 16 weeks, the participants answers a brief online questionnaire that asks about the IBS symptoms while following the avoidance diet. After the 16 week avoidance diet and final questionnaire are completed, those participants who were on the sham diet will be told of their true food allergies which they may try avoiding on their own.
This will be a 6-month randomized clinical trial with two arms: moderately carbohydrate-restricted diet and a fat-restricted control diet. This 6-month study will have 2 phases: a 12-week controlled feeding phase and a 12-week "free living" phase. During the controlled feeding phase, all food will be provided to the families of the participants for the entirety of the 12 weeks. Participants (n=80) will have been diagnosed with NAFLD based on the presence of current evidence of active disease, which will be determined by the ongoing presence of hepatic steatosis estimated by diffusely echogenic liver via ultrasound suggestive of fatty liver and a serum alanine aminotransferase (ALT) level of 45 U/L or greater. All participants will be children and adolescents age 10-17 yrs.; will have an HbA1c \<7.0; and will be overweight or obese (BMI \>85th percentile). It is anticipated that most participants will be sedentary. The investigators will inquire as to routine physical activity at screening. All participants will be asked to maintain their usual level of physical activity throughout the study. Physical activity will be monitored via a smart watch provided to each participant at the beginning of the study, and participants will be queried weekly by the study dietitian regarding changes in physical activity. Participants who use oral contraceptives will be asked to maintain consistent use of these preparations throughout the study. Hormone use will be examined as a potential covariate in statistical analyses.
This study will investigate how maternal emotional state following a controlled stress exposure in pregnancy influences blood glucose and insulin levels after eating a standardized meal, and whether the effects of emotional state on blood glucose and insulin is different after eating a healthy meal (low GI) compared to a less healthy meal (high GI).
African American women have a high prevalence of obesity and type 2 diabetes and do not optimally burn fat and carbohydrates in response to changes in these nutrients in their diets. This research project seek to determine if high intensity interval training (HIIT) exercise training can help healthy, but inactive, premenopausal, non-diabetic women increase their bodies' use of fat and carbohydrates when provided with a high fat or low fat diets. In this study, investigators will measure the rate at which fat is burned in response to weight maintaining low-fat and high-fat diets and how exercise may affect these responses.
This study, at the Western Human Nutrition Research Center (WHNRC), will focus on whether or not achieving and maintaining a healthy body weight is the most important health promoting recommendation of the Dietary Guidelines for Americans (DGA).The investigators hypothesize that improvement in cardiometabolic risk factors resulting from eating a DGA style diet will be greater in people whose energy intake is restricted to result in weight loss compared to those who maintain their weight. The investigators further propose that during a state of energy restriction, a higher nutrient quality diet such as the DGA style diet pattern, will result in greater improvement in cardiometabolic risk factors compared to a typical American diet (TAD) pattern that tends to be lower nutrient quality (more energy-dense and less nutrient-rich.)
The central goal of this proposal is to examine validity and sensitivity of RS-assessed skin carotenoid status as a marker of F\&V intake in a racially and ethnically diverse sample of individuals. First, investigators will examine the association (RS Device Validity) between RS-assessed skin carotenoids and the primary outcomes of objectively-measured plasma carotenoids and self-reported F\&V consumption across four diverse groups: African-American/Black, Asian, White, and Hispanic/Latino (n=213). Then the investigators will conduct a randomized controlled trial to define the relative skin carotenoid responses (RS Device Sensitivity) across racial-ethnic groups, in comparison with plasma carotenoid responses. The investigators will conduct a 6-week randomized controlled trial of a carotenoid-containing juice intervention \[placebo control, low and high dose juice (N=156). Finally, the genetic basis for racial/ethnic group differences in skin carotenoid responses to diet will be investigated through hypothesis-driven genomic analysis of participants from Aims 1 and 2.
The study is evaluating the effects of a standard diet to a low carbohydrate diet in obese women after having a baby. The purpose of the study is to determine if a low carbohydrate diet is associated with improvement in insulin sensitivity in postpartum women.
This randomized, crossover study will include four clinic visits: one screening (day -7) and three test visits (days 0, 2, 4). The objective of this study is to assess the effects of dietary fiber-containing bars, at two doses of fiber, compared to a control product, on postprandial glucose and insulin responses in healthy adult men and women.
This study examine oral bisphenol A consumption on muscle insulin sensitivity and hepatic glucose suppression. Half of the participants will receive a diet plus BPA and the other half will receive a diet plus no bisphenol A.
This randomized, cross-over trial aims to assess changes in body weight, plasma lipids, insulin sensitivity, and postprandial metabolism with a low-fat, plant-based diet and a Mediterranean diet, both followed for 4 months.
the aim of this study is to evaluate whether a Mediterranean diet rich in pasta and other starchy foods with a (Low-GI), as compared with a similar Mediterranean diet containing very little pasta and based on starchy foods with a (Hi-GI) is able to reduce insulin and glucose concentrations during a prolonged test study meal.
The Nutrition Study of the GA2LEN Follow-Survey was designed to investigate the association between usual dietary intake and allergic and respiratory outcomes in adults across Europe. Within this framework, a food frequency questionnaire (FFQ) was designed to ascertain usual dietary intake of 250 food items, which was translated into the languages of the participant centres. Information on daily intake of foods, nutrients, and flavonoids was derived.
This study purpose is to conduct a confirmatory double-blind randomized controlled trial in an inpatient setting of the effects of a tightly controlled gluten-free diet (GFD) to improve negative symptoms in people with schizophrenia or schizoaffective disorder who have antibodies to gliadin (AGA IgG). As part of the project investigators will also confirm outcomes such as cognitive symptoms, changes in peripheral and central inflammation as well as gut/blood brain barrier permeability.
The investigators propose to 1) assess the feasibility, acceptability and preliminary efficacy of a gender- and culturally-sensitive weight loss intervention in 48 overweight/obese Hispanic males ages 18-64 over 12 weeks; 2) assess participant characteristics and process measures related to the uptake of mobile-health (mHealth) technology in overweight/obese Hispanic males over 12 weeks; and 3) assess pathologic changes in the liver in Hispanic men enrolled in a 12-week weight loss intervention using a non-invasive MRI as a therapeutic response biomarker.
The purpose of this study is to determine the effects of change in diet quality (carbohydrate restriction versus fat restriction) on body composition, fat distribution, cardiometabolic risk factors, physical function, and quality of life in aging adults with obesity.
The purpose of this study is to see whether participants with persistent developmental disfluency who report fluctuational disfluency due to vocal cord tension on a day to day basis of can achieve a more normalized fluency by identifying dietary allergen responses and subsequently eliminating these dietary triggers from their daily consumption.
This study is being done to see if allergy patch testing (APT) can help predict effective dietary therapy in patients with eosinophilic esophagitis.