Effects of Brain Stimulation on Food Intake and Behavioral Weight Loss Treatment
This study will determine whether electrical stimulation of an area of the brain called the dorsolateral prefrontal cortex, which is important in determining the feeling of fullness after eating, affects how much food a person eats and weight loss over 4 weeks. It will also compare weight changes in people who attend weight loss counseling sessions and those who do not over this period of time.
Obese, non-diabetic people between 18 and 60 years of age who are in good health and who live in the Phoenix, AZ, metropolitan area are eligible for this study. Candidates must have a body mass index of 35 kg/m(2) or more and weigh less than 350 pounds.
Participants are admitted to the NIH inpatient unit in Phoenix for the first 9 days of the study for tests, which include meal tests to determine eating behaviors and caloric intake, blood and urine tests, glucose tolerance test, weight measurement, psychological assessments and DEXA scan to measure body fat. For 3 of the days, they will be asked to eat all of their food from automated vending machines. Some subjects receive transcranial direct current stimulation (TDCS). For this procedure, electrodes that conduct electricity are placed on the head and arm and the current is turned on for 40 minutes. Some tingling may be felt under the electrodes. Other subjects receive sham TDCS, with the current turned on only very briefly.
After the evaluations, subjects are discharged home from the NIH unit and instructed to eat 25 percent fewer calories than they consumed while on a weight maintenance diet the first 3 days of their inpatient stay. They maintain the lower calorie diet at home for 4 weeks. During this period they come to the NIH unit 3 days a week to receive either real or sham TDCS. Some subjects are also assigned to receive weight loss counseling sessions twice a week, while others are not. At the end of the 4 weeks, subjects return to the NIH unit for a 5-day stay to undergo a repeat DEXA scan, meal tests, psychological assessment and blood tests, and they will eat for another 3 days from the vending machines.
At the completion of the study, all participants may choose to receive 4 more weeks of TDCS or behavioral weight loss counseling, or both.
Behavioral: Behavioral Weight Loss Treatment
Procedure: Transcranial Direct Current Stimulation (TDCS)
Device: Transcranial Direct Current Stimulation (TDCS)
Behavioral: Appetite Control
Procedure: Appetite Control
Device: Weight Control
Behavioral: Weight Loss
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Primary Purpose: Treatment
|Official Title:||The Effects of Transcranial Direct Current Stimulation (TDCS) on Food Intake and Weight Loss|
- Effects of TCDS on weight loss and appetite. [ Time Frame: 9 days; 37 days and 42 days ] [ Designated as safety issue: No ]
- Effect of behavioral intervention on weight loss. [ Time Frame: 9 days; 37 days and 42 days ] [ Designated as safety issue: No ]
|Study Start Date:||August 2008|
|Estimated Study Completion Date:||April 2015|
|Estimated Primary Completion Date:||April 2015 (Final data collection date for primary outcome measure)|
Behavioral: Behavioral Weight Loss Treatment
In our studies of brain function examining areas related to hunger and fullness, a part of the brain called the left dorsolateral prefrontal cortex (DLPFC) was found to be less active in obese versus lean individuals following a meal. Furthermore, in women who have lost and maintained weight loss, the activity in this area following a meal is similar to that of lean women, suggesting that the activity in this area may improve with weight loss. Two recent studies have demonstrated a lack of increase in food craving following non-invasive brain stimulation to the left DLPFC when compared to a sham control group that did not receive brain stimulation.
The aim of our protocol is to investigate the effectiveness of one type of noninvasive brain stimulation technique, transcranial direct current stimulation (TDCS) on food intake in significantly overweight (BMI > 30 kg/m(2) individuals. In study 1, we will enroll individuals who previously participated in this study and compare how anodal (active) stimulation or sham (no stimulation) to the left DLPFC compares to their previous stimulation condition in terms of both weight loss and food intake. The aim of Study 2 is to compare active versus sham anodal LDLPFC stimulation in a new group of volunteers.
Study 2 will be a double-blind parallel study and volunteers will be randomized to receive either active TDCS or no stimulation (sham) to the left DLPFC. During a 4-week outpatient period, both groups will be asked to consume a diet that is a 25% reduction from their calculated weight maintenance calories and come to the Unit 3x per week for stimulation sessions. The primary outcome measurements will be total food intake during 3-d of ad libitum intake from a computerized vending machine system, and weight loss during a 4-week outpatient period. In study 1 we will also examine appetitive hormones and behavioral factors, which might also mediate potential changes in food intake and weight loss following TDCS to the left DLPFC. Positive findings from this study could demonstrate the utility of a novel and safe treatment for severe obesity. Future studies could include longer clinical trials of TDCS with extended follow-up durations.
|Contact: Marci Gluck, Ph.D.||(602) firstname.lastname@example.org|
|United States, Arizona|
|Phoenix, Arizona, United States, 85014|
|Contact: Marci Gluck, Ph.D. 602-200-5312 email@example.com|
|Principal Investigator:||Marci Gluck, Ph.D.||National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)|