12 Clinical Trials for Various Conditions
This research will evaluate nutrition requirements for missions at high altitude (i.e. \>7800 feet above sea level) and the information obtained can be used to optimize nutrient content specifications for combat rations. The objectives are: 1. Determine whether loss of lean body mass resulting from negative calorie balance over a 22-d period at high altitude can be prevented by increasing dietary protein intake. 2. Determine the efficacy of carbohydrate (glucose and fructose) supplementation on aerobic exercise performance at sea level, acute exposure to high altitude, and in response to 22-d period of negative calorie balance at high altitude. 3. Determine cognitive function, sleep patterns, and behavioral responses to high altitude and underfeeding. 4. Determine appetite and eating behavior in response to high altitude and sustained underfeeding. 5. Examine the effects of high altitude, negative calorie balance, dietary intake manipulations on gut health.
This study will determine the impact of 24, 48 and 72 hours of over and underfeeding on energy expenditure as measured in the metabolic chamber at the UNC Chapel Hill Nutrition Research Institute (UNC NRI).
As obesity rates worldwide continue to increase, there is a focus on identifying active food ingredients which increase metabolic rate which can be used as a dietary supplement in the treatment of overweight and obesity. Promising animal and cell studies have suggested a role for black pepper and an active component of black pepper, piperine, in energy expenditure. However, the effects of black pepper have not been determined in humans. The investigators hypothesis if that consumption of 1.5g black pepper (0.5g in each of three meals over one day) will result in an elevation in 24-h resting energy expenditure when contrasted to a control day (no black pepper, same diet intake).
The work of Nau et. al (Nau KL, Bromberg MB, Forshew DA, Katcha Vl. Individuals with amyotrophic lateral sclerosis are in caloric balance despite losses in mass. J Neurol Sci 1995;129 :47-49) showed that patients in the early stages of ALS initially increase their body fat. Another study showed that advanced ALS patients on mechanical ventilation were actually hypometabolic, supporting a hypothesis that ALS patients' daily oral intakes of calories fail to match their energy requirements, thus exacerbating their condition. This current study investigates and compares substrate utilization using a metabolic cart in controls and in ALS patients who are on and off ventilatory support to examine differences in substrate utilization between the two groups of ALS patients and the controls. (Substrate utilization is essentially the percentage of fats, carbohydrates, and protein utilized by the body.) The study will increase our understanding of the nutritional needs of ALS patients and improve our ability to provide the best possible nutrition in progressive illness.
Exercising in the fasted state results in greater fat oxidation during exercise and results in decreased caloric intake in the meals after exercise. However, the studies that examine fasted vs. fed exercise utilize a carbohydrate-based breakfast, which can increase blood glucose and insulin concentrations, which is considered a negative consequence. A protein breakfast, which can increase satiety and rest of day energy intake could also increase resting energy expenditure as well as fat oxidation during exercise. However, comparisons between fasting exercise and pre-exercise breakfast macronutrient intake (i.e., carbohydrate vs. protein) have not been made. Therefore the purpose of this study is to investigate if eating breakfast and the composition of this breakfast before exercise has an effect on the food eaten throughout the rest of the day.
The primary purpose of this study was to examine the acute effects of a multi-ingredient pre-workout supplement versus an ergogenic dose of caffeine (6 mg/kg) on energy expenditure during low-intensity exercise. The effects of these substances on substrate utilization, gas exchange, and psychological factors were also investigated. Twelve males (mean ± SD: age = 22.8 ± 2.4 years) completed three bouts of 60-min of treadmill exercise at 4.8-6.4 km/hr on separate days after consuming a pre-workout supplement, 6 mg/kg of caffeine, or placebo in a randomized fashion. The pre-workout and caffeine supplements resulted in significantly greater energy expenditure (p \< 0.001, p = 0.006, respectively), VO2 (p \< 0.001, p = 0.007, respectively), VCO2 (p = 0.006, p = 0.049, respectively), and VE (p \< 0.001, p = 0.007, respectively), but not rates of fat or carbohydrate oxidation or respiratory exchange ratio compared to placebo (collapsed across condition). In addition, the pre-workout supplement increased feelings of alertness (p = 0.015) and focus (p = 0.005) 30-minutes post-ingestion and decreased feelings of fatigue (p = 0.014) during exercise compared to placebo (collapsed across condition). Thus, the pre-workout supplement increased energy expenditure and measures of gas exchange to the same extent as 6 mg/kg of caffeine with concomitant increased feelings of alertness and focus and decreased feelings of fatigue.
A substantial percentage of individuals with bulimia nervosa (BN) also meet criteria for a co-occurring substance use disorder, such as alcohol abuse or dependence; however, research examining this sub-group of patients with BN is limited. Understanding characteristics common to both eating and alcohol use disorders may enhance understanding of the mechanisms that could contribute to the co-occurrence and perpetuation of these disorders. Individuals with BN and alcohol use disorders appear to share some behavioral traits, and therefore, the primary aim of the current study is to compare patients with BN with and without an alcohol use disorder and normal controls on measures assessing an individual's mood and ability to perform certain tasks. Participants will be asked to complete computer-administered and paper-and-pencil assessments and two laboratory test meals on separate days. By probing the underpinnings of BN and alcohol use disorders, the investigators can determine whether these disorders have a shared diathesis, which will lay an essential foundation for future research to examine biological and genetic correlates of these disorders. Finally, as little is known about the treatment of patients with BN and a co-occurring alcohol use disorder, an exploratory aim of the current study is evaluate the suitability and efficacy of a 20-session cognitive-behavioral treatment (CBT) addressing both bulimic symptoms and alcohol use.
This study will randomize 64 non-treatment seeking individuals who smoke cigarettes daily in a double-blind, placebo-controlled laboratory study testing the effects of cytisinicline on the neural substrates of cigarette cue reactivity.
Children who have previously participated in the study "MI Energy" will be invited to participate in "SUPER kids". Investigators want to better understand differences in nutrient use (e.g., fatty acid and carbohydrate) during rest and exercise in children of varying body types and activity levels.
The investigators aim to establish a protocol for metabolic rate measurements obtained using continuous monitoring of oxygen consumption and carbon dioxide production in a whole room calorimeter setting.
Over one million individuals in the United States meet criteria for cocaine use disorders. Relapse rates are highest among cocaine-dependent (CD) populations. Social stress is a significant risk factor for relapse. Data from human neuroimaging studies suggest that "top-down" prefrontal cortical inhibition of amygdala activity controls emotional responses to social stimuli. A growing literature suggests that hypoactivity in the medial prefrontal cortex coupled with increases in amygdala activity underscore the vulnerability of CD individuals to relapse. Neuroimaging studies of corticolimbic network activity (functional connectivity) have been conducted in CD subjects at rest. Compared with healthy controls, CD subjects exhibited lower corticolimbic connectivity and the degree of corticolimbic uncoupling was associated with time to relapse. Studies measuring corticolimbic connectivity during exposure to a social stress task in CD subjects could provide critical insight into the neurobiologic mechanisms that underscore the sensitivity of CD individuals to social stress. Moreover interventions that improve corticolimbic connectivity in CD subjects may be effective therapeutic strategies for preventing relapse in CD populations. Oxytocin (OT) is an anxiolytic neuropeptide that attenuates amygdala responses to aversive social cues. In order to better understand the neurobiologic mechanisms that control emotion-related behavior in CD populations, we propose a double-blind placebo (PBO) controlled study using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to measure (1) corticolimbic functional connectivity during the Montreal Imaging Stress Task (MIST) and (2) amygdala activity in response to an implicit facial affect recognition paradigm in groups of CD individuals (CD n=80) and healthy non-dependent controls (HC, n=80). Prior to the scanning session, participants will receive either intranasal OT (24 IU) or PBO spray (n=40 per treatment group). The order of the tasks will be counterbalanced.
This study will test the hypothesis that a medication called tolcapone (Brand Name: Tasmar) will help reduce cognitive problems that smokers experience when they quit. This study will also determine whether the benefits of this medication differ depending on a smokers' genetic background.