Identifying Predictors of Success and Valid Measures of Eating Behavior and Diet Satisfaction in a Portion-control Weight Loss Trial PDF Download

Author: Brittany James
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Languages : en
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Book Description
Controlling portion size has been shown to have a significant impact on energy intake in experimental work and on weight management in longer-term studies. However, there is little evidence directly comparing different portion-control strategies in the context of a behavioral weight loss trial. Identifying the factors that can have a long-term impact on weight management could have a beneficial role in improving long-term outcomes. Study 1 focused on identifying early predictors of weight loss as a key part of developing personalized treatment to promote long-term success. Few individual factors/characteristics have been identified that predict weight loss during intervention, other than early weight loss itself. Women with overweight or obesity (n=186, meanSD age 50.010.6 y, BMI 34.04.2 kg/m2) participated in a one-year randomized controlled trial examining the effect of portion-control strategies on weight loss. Repeated assessment allowed evaluation of early change in eating behaviors and psychological factors in the first month of intervention as predictors of weight-loss trajectory from baseline to Month 3 and Month 12. Across all participants, greater increases in dietary restraint and healthy lifestyle ratings after one month, as well as greater decreases in disinhibition, predicted more rapid weight loss from baseline to Month 3. Greater increases in restraint and healthy lifestyle ratings predicted more rapid weight loss and slower regain from baseline to Month 12. Restraint remained a significant predictor after controlling for early weight loss. Initial improvement in psychological and behavioral measures predicted 3-month and 12-month weight loss. For individuals with less improvement, early additional support or tailored treatment could promote long-term success. Study 2 honed in on eating behavior measurement, an area that is often associated with weight loss. Using data from the same one-year weight loss trial, the Three-Factor Eating Questionnaire (TFEQ), a valid 51-item measure of restraint, disinhibition, and hunger subscales, was compared to the newer 16-item Weight-Related Eating Questionnaire (WREQ), which measures routine and compensatory restraint and external and emotional eating. In the trial, both questionnaires were administered five times to 186 women (meanSEM, age 500.35 y, BMI 340.14 kg/m2). Confirmatory factor analysis was conducted on baseline WREQ data and correlations were calculated between TFEQ and WREQ subscales. Multilevel models evaluated the relationship between each subscale and weight change over time. Factor analysis revealed a WREQ structure consistent with previous research, and corresponding subscales on the TFEQ and WREQ were correlated. Lower baseline TFEQ restraint predicted greater weight loss. Across five administrations, TFEQ and WREQ restraint scores were positively related to weight loss (p