This study investigates the hormones that the body produces in response to food intake and in response to stress, and the way that stress influences food intake. In particular, it compares the hormone levels and food intake of people with and without binge eating disorder. In order to find out how these appetite- and stress-related hormones are linked to brain activity, the study also includes an fMRI scan, a non-invasive procedure that looks at which regions of the brain are most active during a food-related scenario.
The objectives are to study appetite-related hormones regulating food intake under normal conditions and following a stressor in the morning and evening (when most binge episodes occur), to help reveal biological mechanisms in BED. We plan to enroll: 32 obese Ss with BED (16m, 16f), 32 obese Ss without BED (16m, 16f) and 32 normal-weight Ss without BED (16m, 16f). Height, weight, waist circumference, and body fat will be assessed during a first appointment. On two different days separated by at least a week, Ss will ingest a fixed liquid meal once in the morning and once in the evening. Appetite ratings and collections of blood and saliva to measure hormones will continue for 2 hours after the fixed meal. This will be followed on each day by a laboratory stress protocol (Socially Evaluated Cold Pressor Test; SECPT), and then consumption of an ad libitum meal 30 minutes later. On one day during the protocol, the participant will collect saliva using a swab immediately after waking and again at 08.00. In order to capture more naturalistic eating episodes, all Ss will additionally record food intake, rate appetite, and measure salivary cortisol before and after one evening meal, and one after-dinner snack (or after-dinner binge for BED Ss). On two additional days, we will use fMRI to assess brain activation in response to high-palatability food (HPF) relative to low-palatability food (LPF) or non-food (NF) visual cues following the SECPT and a control condition using warm water. On each day, following the fMRI scan, an ad libitum meal will be consumed.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
96
Subjects ingest a fixed meal, with blood draws to measure appetite hormone levels taken before and after the meal.
Subjects then undergo the Socially-Evaluated Cold Pressor Test, with blood draws to measure appetite hormone levels taken before and after the test.
Subjects are presented with an ad libitum buffet meal.
St. Luke's Hospital
New York, New York, United States
Appetite-related Hormones and Appetite Ratings in Relation to Fixed Meal and Cold Pressor Test
Blood and saliva concentrations of hormones influencing appetite will be measured at systematic intervals (-15, 0, 10, 30, 60, 90, 120 min) before and after the morning fixed meal at 10.00 and the evening fixed meal at 17.00. Appetite will additionally be rated at each assessment point. This will be followed by a cold pressor test, and then 30 min later by an ad libitum meal 30 min later, with blood and saliva measurements taken before and after completion of the meal.
Time frame: Assessed at systematic intervals (-15, 0, 10, 30, 60, 90, 120 min) before and after the morning fixed meal at 10.00 and the evening fixed meal at 17.00
Cortisol Awakening response
On one weekday morning during the 3-week participation period, participants will take one saliva measurement on awakening and at 08.00 while still fasting. Awakening and 08.00 cortisol levels are expected to be higher in BED compared with nonBED Ss, and in obese nonBED compared with normal-weight nonBED Ss.
Time frame: Assessed on one weekday morning during the 3-week participation period
Psychological Scales
Various questionnaires will be administered to test relationships between outcomes (e.g., intake, hormone levels), and psychological constructs including depression, perceived stress, external and emotional eating and restraint, binge-eating behavior, and night eating. Outcomes will be correlated with scale scores, and scores will be compared between groups. Among other relationships, we anticipate positive correlations between binge eating score, ad libitum intake and ghrelin SECPT response. Psychological scores will be entered as covariates as appropriate.
Time frame: During one initial consultation and on two subsequent visits at least 1 week apart
Body Weight, Body Composition and Gender
Measurements will include height, weight, waist circumference, total body fat from BIA, and cross-sectional abdominal MRI to estimate central, visceral, and subcutaneous fat. Each adiposity index will be correlated with outcomes and compared between groups.
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Time frame: During one initial consultation and on two subsequent visits at least 1 week apart