Clinical Research Directory

Developing Biomarkers of Dietary Intake

Background: \- Researchers who study health and nutrition are interested in developing more accurate methods of determining what people eat from day to day and how it affects their general health. In particular, better methods are needed to determine if people are accurately remembering what they ate. One possible method involves the use of biomarkers, or indicators in urine, blood, saliva, fat, and hair, which are related to the intake of a particular food in a consistent way. One set of biomarkers in blood samples and hair may be used to determine the relative amount of meat, fish, and soda (corn/sugar cane) in a person s diet. However, more research is needed to study the effectiveness of using these biomarkers to accurately track dietary intake. Objectives: \- To validate the use of biomarkers as representative of specific dietary intake patterns (meat/fish/soda). Eligibility: \- Healthy, nondiabetic men between 18 and 65 years of age. Design: * This study involves an initial screening visit and a 12-13 week inpatient dietary study period. * Participants will be screened with a medical history and physical examination, as well as blood and urine samples and a glucose tolerance test to exclude individuals who have diabetes. * After 3 days of a standard weight-maintaining diet, participants will have a glucose tolerance test and a body fat scan; provide hair, blood, and fat tissue samples; and complete questionnaires and performance tests. * Participants will spend one day in a metabolic chamber to measure their energy expenditure and general metabolism. * Participants will then be randomized into one of eight carefully designed diets for 12 weeks. The diets will differ in the amount of meat, fish, and soda, including one diet where none of the three biomarker-related foods will be permitted. Blood samples will be collected throughout the study diet period. * At the end of the 12-week study diet period, participants will provide additional hair, blood, and fat tissue samples, and will have a second metabolism assessment in the metabolic chamber....

Developing Biomarkers of Dietary Intake: Dose Dependent Measurement of Sugar Intake

Background: Diet is one of the most modifiable behaviors affecting health. But diet assessment measures that are based on self-report can be inaccurate. Researchers want better ways to address the role of diet in chronic disease. They want to see if stable isotopes can be used to better assess what people eat. Objective: To see if stable isotopes can help scientists identify things people eat. Eligibility: Healthy adults ages 18 to 65 Design: Participants will be screened with a medical history and physical exam. They will have blood and urine tests. These tests will be repeated during the study. Participants will stay in the inpatient unit of the NIH in Phoenix, Arizona, for 13 weeks. For 7 days, participants will eat a diet prepared by the NIH kitchen. They will get balanced meals that are 50% carbohydrates, 20% protein, and 30% fat. Then participants will be randomly placed on one of 3 diets containing different percentages of carbohydrates from soda. Participants height and weight will be measured. The amount of fat and muscle in their body will be measured by body scans that are similar to x-rays. Participants will have oral glucose tolerance tests. They will consume a sugar drink and then give blood samples over 3 hours. Participants will give hair and stool samples. Participants will complete a diet questionnaire. It assesses their food intake over 24 hours. Participants will complete behavioral questionnaires and computer performance tests. Participants will have fat biopsies taken from their stomach and thigh. Participants will have three 24-hour stays in a metabolic chamber. It is used to measure metabolism.

Predicting Weight Gain and Weight Loss Associated With Overeating or Fasting

This study will investigate how to better predict why some individuals gain or lose weight more easily than others. It will examine whether the increase in the amount of energy a body burns in 24 hours with overeating or the decrease over 24 hours with fasting can help determine how easily someone gains or loses weight. Healthy people between 18 and 60 years of age who have a body mass index (BMI) between 18.5 kg/m(2) and 24 kg/m(2) (for overfeeding study) or a BMI greater than 27 kg/m(2) with a body weight less than 350 pounds (weight loss study) may be eligible for this study. The study requires a 10-week admission to the NIH Clinical Center (2-week baseline, 6-week overfeeding/weight loss, 2-week post-weight change). Participants undergo the following tests and procedures during the hospital admission: * Medical history, physical examination and laboratory studies * Questionnaires to assess eating behavior, food preferences, body composition, and activity level * Body composition assessment (height, weight, waist circumference, and fat mass and muscle content through DXA and MRI scans) * Oral glucose tolerance test * Meal test to measure the response of certain hormones to food * Activity monitors to determine activity level * Metabolic chamber study to measure calories burned over 24 hours and monitor body temperature * Free-living energy use study to measure calories burned under normal home conditions over 7 days * Fat and muscle biopsies * Dietary intervention: Measurements of food intake and energy loss over a 6-week overfeeding (1.5 times the subject s normal food intake) or weight loss (one-half the subject s normal food intake) program Followup procedures after the inpatient stay: * Height and weight measurements at 6 months (overfeeding study participants) and monthly for the first year, at 3-month intervals for the second year, and then yearly for 3 more years (weight loss study participants) * Yearly visits (2-night inpatient stay) for all participants for repeat meal test, DXA, oral glucose tolerance test, behavioral questionnaires and, in women who can become pregnant, pregnancy test

Soluble and Osmotic Fibre (SOLOS) Diet for Constipation

This research aims to study the dual effectiveness of incorporating soluble fibre and osmotic carbohydrates (SOLOS), with or without restricting fructans and GOS, and present novel findings in managing GI symptoms in patients with functional bowel disorders with constipation. These findings may also support researchers and clinicians in shaping new dietary approaches in the management of general constipation symptoms.

Comparison of Quality of Life During a Flare of Crohn's Disease Treated With Prednisolone or aCDED With PEN in Adult Patients

Crohn's disease (CD), a type of inflammatory bowel disease (IBD), is on the rise globally. Although medical treatments have advanced, CD still leads to significant health issues due to disease progression and medication side effects. Exclusive enteral nutrition (EEN) is a recommended first-line treatment for pediatric CD, proving more effective than oral corticosteroids without side effects. However, EEN demands strict adherence, making it challenging for patients, particularly adults. In 2019, Levine et al. found that a combination of a specific diet (CD exclusion diet, CDED) and partial enteral nutrition (PEN) was as effective as EEN in inducing remission in pediatric patients, with better tolerance and adherence. CDED focuses on whole foods and aims to minimize harmful dietary components affecting the gut. In clinical practice, an adapted CDED (aCDED) has been used to provide more food choices, but it lacks validation in clinical trials. An aCDED that considers regional and seasonal food variations could enhance patient adherence and align with modern dietary preferences. This study aims to compare the quality of life during a flare up of Crohn's disease treated with standard of care or an adapted Crohn's disease exclusion diet with partial enteral nutrition in adult patients.

Protein Supplementation During Dialysis (PROSED)

When a patient has dialysis some nutrients are lost in the process. Nutritional losses include protein, trace elements (i.e. zinc, copper and selenium) and water-soluble vitamins (Vitamins C and B). These nutrients are essential for normal body function, including a good immune system and nutritional status. For example, on average the protein losses during a dialysis session (the process where the blood is cleaned via a machine and special fluid) is equal to 6g of protein/day (which is the equivalent of the amount of protein in 1 egg). Protein needs for the general population are 0.8g protein per kg of body weight. Because people on dialysis lose protein via the dialysis, it is thought that these people need to eat more protein. Currently, in clinical practice for people receiving dialysis, the guidelines are to aim for 1.1 -1.4g of protein per kg of body weight. However, the research is old and very weak. Dialysis treatments have changed over the past 40 years, and the investigator does not know if the replacement of these nutritional losses is important to how well people do on dialysis and if they have any effect on survival. Previous research is mostly limited to haemodialysis (a type of dialysis that requires a machine which cleans the patients' blood via special filters) and peritoneal dialysis (this is a type of dialysis which happens via the patients' tummy). There is no research on the nutritional supplementation in home HD and nocturnal HD. Our research will investigate if a higher protein provision leads to a reduction is hospital admissions and improved outcomes in patients receiving dialysis.

Effect of Access to Dietary Intervention in a Dialysis Unit

Objective: The aim of this study is to explore the effect of access to individual dietary counselling by a dietitian in the dialysis unit on biochemical values (phosphorus and potassium), diet, nutritional status, quality of life (QoL) and health literacy (HL). Hypothesis: Having access to a dietitian can better laboratory values and affect dietary intake, nutritional status, QoL and HL in a positive matter. Method: Pilot cluster RCT study in three the dialysis units in Region Zealand. Clustering of people on dialysis the same day to either intervention or control group. The groups is expected to be similar regarding clinical characteristics. Primary outcome: Change in average p-phosphate Secondary outcomes: Change in average p-potassium, number of phosphate binders, number of potassium binders, HeartDiet-score, Nutritional Status, Adherence to diet (End Stage Renal Disease Adherence Questionnaire), Quality of life (Kidney Disease Quality of Life Short Form) and Health literacy (Health Literacy Questionnaire) Intervention: The intervention group receives an initial individual dietary interview, monthly follow-up and weekly access to a dietitian in the dialysis unit for four months. The control group receives usual care with referral to a dietitian when needed.

Time-Restricted Eating to Address Persistent Cancer-Related Fatigue

This study will assess the feasibility of delivering a 12-week time-restricted eating intervention as well as the intervention's preliminary efficacy on persistent cancer-related fatigue among cancer survivors compared to a general health education control. Participants will be randomized 1:1 to one of two arms: time-restricted eating or control. Those in the intervention arm will self-select a 10-hour eating window in which to consume all food and beverages (water is allowed any time, black coffee and unsweetened tea are allowed in the morning). Both groups will receive weekly educational tips on healthy lifestyle behaviors in cancer survivorship. This study will also explore relationships between fatigue, circadian rhythm, and glucose metabolism. The hypothesis is that recruitment will be feasible, and participants will adhere to time-restricted eating and complete study activities over the course of the 12 weeks. The second hypothesis is that time-restricted eating will lead to less fatigue at 12 weeks compared to the control, accounting for baseline fatigue levels.