Evaluating the Power of Food Scale in obese subjects and a general sample of individuals: development and measurement properties

• Published in: International Journal of Obesity Vol. 33; no. 8; pp. 913 - 922
• Main Authors: Cappelleri, J.C, Bushmakin, A.G, Gerber, R.A, Leidy, N.K, Sexton, C.C, Karlsson, J, Lowe, M.R
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2009; Nature Publishing Group
• Subjects: adults; Algorithms; Biological and medical sciences; Body Mass Index; Clinical trials; Complications and side effects; Development and progression; diet study techniques; dietary surveys; Eating behavior; Epidemiology; Factor Analysis, Statistical; Feeding Behavior; Feeding Behavior - psychology; Female; Food; Food and nutrition; Food habits; food-abundant environments; Health aspects; Health Promotion and Disease Prevention; Humans; Internal Medicine; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; normal values; Nursing; obese subjects; Obesity; Obesity - psychology; Omvårdnad; original-article; Overweight; Polls & surveys; Power of Food Scale; Psychology; Psychometrics; psychosocial factors; Public Health; Questionnaires; R&D; Research & development; Risk Factors; Surveys and Questionnaires; United States; Weight control; weight management; United States; United States > US; weight management; Power of Food Scale; obese subjects; Human; Obesity; Nutrition; Sample; Body weight; Nutrition disorder; Weight loss; Metabolic diseases; Corporal biometry; Properties; Nutritional status; Power; Food
• ISSN: 0307-0565; 1476-5497; 1476-5497
• DOI: 10.1038/ijo.2009.107

Background: The Power of Food Scale (PFS) was developed to assess the psychological impact of today's food-abundant environments. Objective: To evaluate the structure of the PFS in diverse populations of obese and nonobese individuals. Design: Data were obtained from obese adults in a clinical trial for a weight management drug (n=1741), and overweight, obese and normal weight adults in a Web-based survey (n=1275). Exploratory and confirmatory factor analyses were used to investigate the PFS structure using the clinical data. The model developed was then tested using the Web-based data. Relationships between PFS domains and body mass index (BMI) were examined. Logistic regression was used in the Web-based survey to evaluate the association between obesity status and PFS scores. Results: Clinical data indicated that the scale was best represented by a 15-item version with three subscale domains and an aggregate domain (average of three domains); this was confirmed with data from the Web-based survey (Comparative Fit Index: 0.95 and 0.94 for the clinical and Web-based studies, respectively). Cronbach's for both data sets was high, ranging from 0.81 to 0.91. The relationships between BMI and each domain were weak (and approximately linear). A full category increase in PFS domain score (range 1-5) increased the odds of being obese 1.6-2.3 times. Conclusions: The 15-item PFS is best represented by three domains and an aggregate domain. The PFS may provide a useful tool to evaluate the effects of obesity treatments on feelings of being controlled by food in an obesogenic food environment.