Many authors of publicly available top-selling nutrition books in Canada are without clinical nutrition credentials, do not cite evidence, and promote their own services or products.

The accuracy of books as public nutrition resources varies substantially; whether authors of publicly available nutrition books possess related experience, cite scientific evidence, or have other financial incentives has not been assessed thoroughly. This study aimed to determine if publicly available top-selling nutrition books are written by authors who (1) have relevant expertise, (2) cite scientific evidence, and (3) benefit financially in other ways. Best-selling nutrition books were gathered from Amazon Canada. Differences in scientific citations and financial incentives were compared between authors with and without credentials. Authors who were Doctor of Medicine (MD), registered dietitians (RD), chiropractors, or naturopathic doctors had more in-text citations (56% versus 25%; p  = 0.014) and cited more scientific articles (83% versus 50%; p  = 0.0045) compared to all other authors. The majority of authors of publicly available top-selling nutrition books in Canada did not have MD/RD credentials. Many of the authors promoted their own services or products, regardless of credentials.