This couple had such success on the Keto Diet they wrote a book about it.

A cancer researcher and kinesiology professor and a health journalist found out about the Keto Diet and after 6 years of success decided to write a book about the science behind it.

Dave Harper and Dale Drewery are not only romantic partners, they’re keto diet partners as well. In 2013, the couple, who live in Vancouver and have been together for 22 years, decided to give the high-fat, low-carb ketogenic diet a try.
Six years and 40 or so pounds later, they’re still going strong on keto. In fact, they recently published a book, BioDiet, that covers the science behind the super trendy plan, why it can improve overall health, plus practical tips on how to stick with it long-term.
Harper, a cancer researcher and kinesiology professor at the University of the Fraser Valley, tells Health that he and Drewery, who works as a health journalist, started the plan while he was researching the impact of diet on long-term health. 

Health.com