Obesity Clinical Trials

The goal of this clinical trial is to learn about the effect of urolithin A, a dietary supplement, on blood flow in middle-aged adults with obesity. The main question it aims to answer is: - Does urolithin A supplementation improve blood flow in large and small blood vessels in middle-aged adults with obesity? Participants will be asked to: Take the dietary supplement daily for 4 weeks Attend two study visits to have their blood vessels checked, answer questionnaires, and give a sample of blood Researchers will compare people who took the dietary supplement with others who took a placebo to see if the blood flow in the blood vessels improved. Read Less

Reduction in food reinforcement appears to be a principal way by which bariatric surgery lowers energy intake to promote weight loss and other health improvements. However, surgical modulation of mechanisms that influence food reinforcement is variable with some patients appearing more resistant to these effects than others. This "resistant" phenotype, characterized by high levels of hedonic hunger (i.e., eating for pleasure in the absence of hunger) and disinhibition (i.e., susceptibility to cues that promote overeating), can undermine surgical efficacy. Bariatric surgery patients who demonstrate this high-risk eating phenotype may benefit from strategies that can directly target neural mechanisms of food reinforcement. Repetitive transcranial magnetic stimulation (rTMS), a noninvasive procedure that delivers magnetic pulses to stimulate or inhibit nerve cells in the brain, has successfully been used to target dysregulated brain reward circuitry to diminish the reinforcing properties of addictive drugs, such as cocaine. rTMS might have a similar effect on people who have a strong drive to eat in response to the reward of palatable foods. No study has directly examined how rTMS impacts the reinforcing value of food and related brain reward processing among people who find food highly reinforcing. The reinforcing value of food can be measured by comparing how much work a person will choose to do to access that food versus an alternative reinforcer (i.e., relative-reinforcing value of food [RRV]). In this study, we aim to: (1) determine whether rTMS reduces the RRV relative to money; and (2) measure acute rTMS-induced modulation of reward processing with electroencephalography (EEG). Preoperative bariatric patients (n=10) will attend 2 study sessions, at least 1-week apart, with RRV and reward measures completed while EEG is collected before and after a rTMS session. With condition blinding and counterbalancing, participants will be randomized to active rTMS on one day and sham rTMS on the other day. Participants will arrive fasted in the morning, receive a standardized breakfast, complete the RRV and reward tasks during EEG before rTMS (pre-rTMS EEG), receive rTMS, then complete the RRV and reward tasks during EEG after rTMS (post-rTMS EEG). During the active condition, rTMS will be applied to the dorsolateral prefrontal cortex because this region is functionally and structurally connected to the striatum, an area necessary for reward processes. These procedures will allow for comparison of pre- to post-test rTMS changes in behavioral (RRV) and neural modulation (EEG) of food reward between the active and sham conditions. Read Less

The purpose is to optimize the EMPOWER program by integrating strategies to reduce food cravings, a critical yet often overlooked factor for long-term success in weight management. The objective of this study is to determine the efficacy of craving coping strategies on weight loss outcomes by conducting a randomized controlled trial. Participants will be randomized to receive one of the two strategies to manage food cravings. Read Less

The changing food environment, with increasingly abundant ultra-processed food (UPF) options, may directly contribute to rising rates of obesity, though it is unknown which ingredients in UPF elevate their reinforcing nature in a way that may lead to overconsumption. The proposed study is the first to systematically examine differences in the rewarding characteristics of and physiological and metabolic responses to UPFs that are high in fat, refined carbohydrates (like sugar), or both. Understanding the biobehavioral underpinnings that enhance the reinforcing potential of ingredients in UPF (e.g., fat vs. refined carbohydrates) can inform novel intervention targets for the treatment of overeating and obesity. Read Less

The purpose of this project is to examine the impact of increases in brain insulin on sympathetic nervous system activity, as well as peripheral and cerebral blood flow in humans. Read Less

Socioceconomically disadvantaged individuals typically have poor outcomes in behavioral weight loss interventions, but the reasons for this are unknown. This project will characterize the mechanisms through which adverse daily experiences and present bias -- a cognitive adaptation to harsh and unpredictable environments -- account for disparities in weight loss outcomes. Read Less

We will study obese hypertensive subjects in a randomized, crossover study to determine if two weeks sympathetic blockade improves endogenous glucose production. Subjects will be studied on 3 different occasions after two weeks of receiving either placebo, amlodipine (vasodilator arm) or moxonidine (study arm). The order of the studies will be determined using computer-generated randomization. Patients will be blinded as to which treatment they are receiving on each day. An investigator blinded to the treatment assignment will perform the analysis of the data. Read Less

The purpose of this project is to examine key mechanisms contributing to sex-differences in hypoxic vasodilation and the impact of obesity, with particular emphasis on the sympathetic nervous system. Read Less

Nearly 8 in 10 Veterans meet criteria for overweight/obesity. Three evidence-based treatment options are available within VA (behavioral weight management [MOVE!], obesity medications, and bariatric surgery). However, all treatments are significantly underutilized. This study will evaluate the effectiveness of a novel intervention designed to increase obesity treatment initiation and subsequently weight loss within VA. The intervention, Teaching Obesity Treatment Options to Adult Learners (TOTAL), involves an educational video and multiple motivational sessions delivered via telemedicine. If effective, TOTAL could be implemented throughout VA without requiring significant resources and could be integrated into the existing VA behavioral weight management program, MOVE!, which is present at nearly every VA medical center. Read Less

The purpose of this study is to examine whether a standardized video education tool will improve knowledge regarding obesity and bariatric surgery and increase bariatric surgery referrals for obese women with endometrial cancer. Read Less

This study aims to determine the daily rate of endogenous synthesis of oxalate using carbon 13 oxalate isotope tracer technique and a low-oxalate controlled diet. Read Less

Approximately 40% of Veterans have obesity and are at increased risk for cardiometabolic disease. Intensive lifestyle-based weight management programs can lead to clinically significant ( 5%) weight loss. The VA's MOVE! program is effective for promoting weight loss and behavior change for those who attend. Unfortunately, MOVE! has low enrollment and high attrition due to several obstacles including low motivation. Mental Contrasting with Implementation Intentions (MCII) is an innovative strategy developed over 20 years of research that uses imagery to increase motivation for behavior change. MCII can be implemented in primary care settings using an easy to teach technique called "WOOP" (Wish, Outcome, Obstacle, Plan) that Veterans then use regularly on their own with the help of paper-based tools or the WOOP app. The research team will evaluate the efficacy and implementation of MCII when combined with telephone-delivered MOVE! vs. telephone-delivered MOVE! alone to enhance weight management outcomes for Veterans in primary care. Read Less