The 17 Day Diet is actually a series of four 17-day cycles, the first of which features a low-carbohydrate, calorie-restricted plan. During the second cycle you "calorie zigzag," or vary your calorie intake daily. Cycle three focuses on what one reviewer calls "a balanced low-calorie diet" while shunning processed food, and cycle four is meant to be a lifelong habit of calorie zigzagging.
Experts like the clean-eating message and encouragement to exercise regularly. However, they aren't thrilled with the gimmicky title and the theory behind the diet, which uses the idea of "metabolism confusion," or keeping your metabolism guessing by frequently modifying your caloric intake. One expert says that while there's no harm in calorie cycling, there's also "no scientific evidence to support the efficacy of calorie cycling or its effect on metabolism." Another describes this approach as "very loosely based on science."
But as one user points out, the maintenance phase of this diet is very similar to what your physician might normally recommend. Users and experts are somewhat evenly split between those who say the diet encourages healthy lifestyle change, and those who say it's a gimmicky or entertaining diversion, but doesn't really change your day-to-day habits. You can also purchase a prepackaged meal plan for $26.42 per day or $184.90 per week (shipping included).
While we found no scientific studies addressing the 17 Day diet, there are outlines with expert commentary on WebMD and CalorieCount.com, along with almost 500 Amazon.com user reviews. ABC News also did a video and print feature on the plan, although no negatives are discussed.
A registered dietitian explains the basic elements of the 17 Day diet and includes input from several other dietary experts. Although they seem to like the diet itself, they dislike the gimmicky title and the plan's theory, which one describes as "very loosely based on science."
Review: 17 Day Diet: Diet Review, Kathleen M. Zelman, MPH, RD, LD
Mary Hartley, a registered dietitian, reviews the basic premise behind the 17 Day diet. She warns that there's no scientific proof for the efficacy of calorie cycling, and says the plan may be an interesting psychological diversion for those with only a few pounds to lose, but it doesn't really address day-to-day behavioral issues. (Note: ConsumerSearch is owned by About.com, which also owns CalorieCount.com, but the two don't share an editorial affiliation.)
Review: What Is the 17 Day Diet?, Mary Hartley, RD, MPH, Jan. 18, 2011
More than 500 reviewers give this diet 4.3 stars out of 5. They say the 17 Day diet is suitable for most people and sometimes does create a lifestyle change; others are upset that the diet lasts longer than 17 days and isn't very different (at least in the maintenance stage) from what doctors usually suggest for healthy eating.
Review: The 17 Day Diet: A Doctor's Plan Designed for Rapid Results, Contributors to Amazon.com
4. ABC News
This short video and print feature recaps the main aspects of the 17 Day diet, and links to an excerpt of the book's first chapter. There are a few brief testimonials from dieters, but no discussion of any potential downsides.
Review: 17 Day Diet: Dr. Michael Moreno's Plan for Weight Loss in Four Cycles Goes Viral, Brian O'Keefe, April 7, 2011