The importance of measuring dietary adherence in a weight loss trial

Numerous weight loss dietary intervention trials have been conducted, however, many of these have neglected to measure dietary adherence or have not measured it in a standardised way. Subsequently, there is a lack of data on how easy these diets are to follow or whether they are effective. Further, a lack of standardisation makes it impractical to compare results between trials. This study aimed to demonstrate the importance of measuring dietary adherence and that a standard definition is needed. Secondary analysis of those who filled in diet records for at least 4 months of a 6 month randomised eating frequency study was conducted. Monthly weight and fat weight were measured using bioimpedance. Three dietary adherence definitions were developed based on those used in published literature. These were analysed for their relationships with weight and fat loss using spearman's correlations and independent samples t-tests comparing the highest and lowest tertiles of adherence. Dietary adherence was positively correlated with weight and fat loss. This illustrates the importance of measuring dietary adherence as weight or fat loss may not be attributable to the dietary intervention itself. The relationships between dietary adherence and weight or fat loss varied greatly according to which of the three overall adherence scores were used which demonstrates the importance of using a standardised definition. All weight loss dietary intervention trials should measure dietary adherence. To enable comparability between weight loss trials, standard criteria for defining dietary adherence is needed.No Full Tex