Stages of change for reducing dietary fat to 30% of energy or less
Date of Original Version
Objective To develop an algorithm that defines a person's stage of change for fat intake ≤30% of energy. The Stages of Change Model describes when and how people change problem behaviors; change is defined as a dynamic variable with five discrete stages. Design A stage of change algorithm for determining dietary fat intake ≤30% of energy was developed using one sample and was validated using a second sample. Subjects Sample 1 was a random sample of 614 adults who responded to mailed questionnaires. Sample 2 was a convenience sample of 130 faculty, staff, and graduate students. Statistics Subjects in sample 1 were initially classified in a stage of change using an algorithm based on their behavior related to avoiding high-fat foods. Dietary markers were selected for a Behavioral algorithm using logistic regression analyses. Sensitivity, specificity, and predictive value of the Behavioral algorithm were determined, then compared between samples using the Z test. Results The following dietary markers predicted intake ≤30% of fat (Ξ2 = 131; P < .0001): low-fat cheese, breads without addded fat, chicken without skin, low-calorie salad dressing, and vegetables for snacks. The specificity of the Behavioral algorithm was validated; the algorithm classified subjects consuming >30% of energy from fat with 93% specificity in sample 1 and 87% in sample 2 (Z = 1.36; P > .05). Predictive value was also validated; 64% and 58% of subjects meeting the behavioral criteria had fat intakes ≤30% of energy (Z = 1.1; P > .05). The algorithm was not sensitive, however; most subjects with fat intakes ≤30% of energy from fat failed to meet the behavioral criteria. The sensitivity differed between samples 1 and 2 (44% and 27%, respectively; Z = 3.84; P < .0001). Applications The Behavioral algorithm determines stage of change for fat reduction to ≤30% of energy in populations with high fat intakes. The algorithm could be used in dietary counseling to tailor interventions to a patient's stage of change. © 1994 Health Management Resources.
Journal of the American Dietetic Association
Greene, Geoffrey W., Susan R. Rossi, Gabrielle R. Reed, Cynthia Willey, and James O. Prochaska. "Stages of change for reducing dietary fat to 30% of energy or less." Journal of the American Dietetic Association 94, 10 (1994): 1105-1112. doi:10.1016/0002-8223(94)91127-4.