The Impact of Weight Bias and Stigma on Energy Misreporting in 24-Hour Dietary Recalls

Obesity research remains a high priority worldwide, given the sustained high levels of obesity (body mass index ≥30 kg/m2) and class III obesity (body mass index ≥40 kg/m2) across many demographic groups. One component of obesity research is the study of how diet can contribute to obesity, and thus it is crucial to evaluate how existing dietary assessment methods perform for people with obesity, and to develop or refine methods to enhance their accuracy. Researchers should be prepared to include more individuals with obesity and class III obesity, a growing demographic, in studies that assess dietary intake. With the inclusion of these groups, it is vital to consider the potential impact of weight bias and weight stigma on dietary research. Weight bias is negative attitudes and stereotypes about people with obesity, while weight stigma is how these attitudes collectively devalue people with obesity, which could result in acts of discrimination. This dissertation: 1) defined the issues of weight bias and weight stigma, and how they affect dietetics practice, including research, 2) determined the representation of participants with class III obesity in studies validating self-reported measures of dietary assessment using doubly-labeled water, and 3) explored how weight bias and weight stigma might impact misreporting of energy intake among people with overweight and obesity. Findings include that: 1) weight bias and weight stigma are important issues when working with people with obesity, and dietetics professionals can address these in many areas of practice; 2) in studies validating self-reported dietary assessment methods using doubly-labeled water, people with class III obesity are underrepresented, and thus the validity of existing methods to assess diet among people with class III obesity requires further research; 3) in a sample of participants with self-reported overweight and obesity, previous experiences of weight stigma were common, though internalized weight bias, weight bias toward others, and experiences of weight stigma were not predictive of the validity of energy intake reporting. Researchers should consider the potential impact of weight stigma on recruitment, retention, and participant experience when working with participants with obesity.