GASTRIC MYOELECTRIC ACTIVITY IN OBESE PARTICIPANTS WHILE VIEWING FOOD IMAGES AND EATING FOOD

Open Access
Author:
Wang, Jiangyue
Graduate Program:
Psychology
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
October 06, 2006
Committee Members:
  • Robert M Stern, Committee Chair
  • William Ray, Committee Member
  • Frederick Martin Brown, Committee Member
  • Arkady Tempelman, Committee Member
Keywords:
  • Electrogastrogram
  • obesity
  • food
Abstract:
Purpose: This study observed the reactions of the stomach to food viewing and food eating in obese people. Method: The participants were 20 obese and 20 normal-weighted undergraduate students, who were required to fast for at least 4 hours preceding the experiment. They viewed a video clip of food for 6 minutes; consumed food till full; and viewed the same video clip of food 30 minutes after the meal. Cutaneous electrogastrograms (EGGs) were recorded during the entire procedure. Questionnaires concerning the participants' perception of somatic and affective changes during the tasks were completed. Results: The percentages of bradygastric, normal and tachygastric EGG activity were very similar between obese group and normal-weighted group during the baseline period. During the first food image viewing, an increase in normal gastric activity and a decrease in bradygastric activity occurred in both groups, but obese participants showed less of an increase in normal gastric activity than normal-weighted participants and the percentage of bradygastric activity was higher in obese group than in the normal-weighted group. During the 30-minute period following the meal, a higher percentage of bradygastric activity and a lower percentage of normal gastric activity were observed in obese participants than in normal-weighted participants. Furthermore, obese participants showed a different pattern of change in 3 cpm and bradygastric activity than normal-weighed participants during the 30 min. The whole 30-min period was divided into five 6-min periods. Obese participants and normal-weighted participants reacted similarly to the second food image exposure, except that a higher increase in 3 cpm activity was observed in the normal-weighted group in the period after the termination of viewing the food images. Conclusions: These data suggest that obese people react to food images and to food eating differently from normal-weighted people. EGG activity in obese participants needs further investigation.