Stress Reactivity Study in Adolescents

In the United States, pediatric obesity has more than tripled in the last 30 years, particularly among certain racial/ethnic groups including African-Americans. This disparity is partially attributable to greater exposure to psychological stress reported in this group (relative to non-Latino whites). Chronic psychological stress leads to weight gain directly through prolonged exposure to biological stress mediators such as cortisol and indirectly through behavioral pathways involving cortisol-induced increases in food consumption. An exciting arena of scientific advancements is focusing on identifying the specific pathways through which chronic stress influences eating behavior with emerging evidence to suggest that food intake, which is commonly increased during periods of stress, may serve as one key mechanism linking stress and obesity, particularly in African-American youth who are disproportionately exposed to chronic stress and have greater access to, and consumption of, energy-dense palatable foods. It is critical to advance understanding of the interplay between stress and food intake in understanding racial/ethnic disparities in pediatric obesity because stress eating represents a modifiable health behavior. That is, increased food intake during periods of elevated stress can be targeted for intervention in ways that may ameliorate the deleterious effects of stress on obesity risk. This project investigated the role of stress eating as a pathway linking chronic stress and obesity in African-American and non-Latino white adolescents.

• Acute Laboratory Stressor (Behavioral), also known as Trier Social Stress Test: The TSST was 20 minutes long and consisted of a five-minute instructional period where participants listened to a pre-recorded tape; a five-minute speech preparation period; a five-minute challenging serial subtraction task; and a five-minute videotaped public speaking task in front of a panel of three evaluative, non-affirming judges dressed in white coats.
• Low affect video (Behavioral): The 20-minute TSST was replaced with a 20-minute low-affect educational film screening.

Primary outcomes

• Food consumption [2 hours]: Change in grams of each food consumed during the control and stress conditions were recorded and calories were calculated using the corresponding nutritional labels.

Secondary outcomes

• Salivary cortisol area under the curve [2 hours]: During the control and stress conditions, saliva samples were taken at times 10, 25, 58, 88 and 118 minutes after arrival to analyze cortisol responses to the TSST. Area under the curve was calculated from the initial cortisol sample collected to the final cortisol sample collected: \[AUC=(x2+x1)/(t2-t1) + (x3+x2)/(t3-t2) + (xk+xj)/(tk-tj)\].
• Salivary alpha amylase area under the curve [2 hours]: During the control and stress conditions, saliva samples were taken at times 10, 25, 58, 88 and 118 minutes after arrival to analyze alpha amylase responses to the TSST. Area under the curve was calculated from the initial alpha-amylase sample collected to the final alpha amylase sample collected \[AUC=(x2+x1)/(t2-t1) + (x3+x2)/(t3-t2) + (xk+xj)/(tk-tj)\].

Other outcomes

• Heart rate area under the curve [2 hours]: Heart rate was taken throughout the control and stress conditions. Area under the curve was calculated from the initial heart rate collected to the final heart rate sample collected \[AUC=(x2+x1)/(t2-t1) + (x3+x2)/(t3-t2) + (xk+xj)/(tk-tj)\].
• Blood pressure area under the curve [2 hours]: Blood pressure was taken throughout the control and stress conditions. Area under the curve was calculated from the initial blood pressure reading collected to the final blood pressure reading collected \[AUC=(x2+x1)/(t2-t1) + (x3+x2)/(t3-t2) + (xk+xj)/(tk-tj)\].

Sex: All, ages: 14 Years to 19 Years, accepts healthy volunteers

Inclusion Criteria:

* Overweight and obese adolescents ages 14- 19 years

Exclusion Criteria:

* Currently pregnant
* Had been enrolled in a weight loss program in the last 6 months
* Were current smokers (e.g., tobacco, marijuana, vaping)
* Were diagnosed with a mental health condition (e.g, depression)
* Were diagnosed with a chronic condition known to affect weight, appetite, blood glucose or insulin levels (e.g., diabetes)
* Were taking medications known to affect metabolic processes (e.g., growth hormone, ritalin, metformin, etc)
* Had food allergies, intolerances, or other dietary restrictions

• Rebecca Hasson, PhD, Principal investigator, University of Michigan