Considerable evidence proves that self-reported dietary intake using written diaries or recalls are subject to bias resulting in poor accuracy. While dietary intake data are needed to drive many nutritional policies, the obesity epidemic has increased the need to assess diet with absolute accuracy. This book reviews the field of research methods in dietary assessment. Chapters cover laboratory and free-living dietary methods; computer assisted recall methods; dietary energy intake models; dietary and isotopic biomarkers; photographic diet diaries; chewing and swallowing sensors for detection; and novel electronic monitoring devices under investigation.