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Macmillan Childrens Publishing Group

Clean & Lean

30 Days, 30 Foods, a New You!

Ian K. Smith

St. Martin's Press



I have always professed that understanding nutrition and successful weight loss is a lifelong process. I continue to believe that. This is especially the case when trying to create programs that are doable, effective, scientifically based, and sustainable. Despite the numerous books I’ve written on weight loss and nutrition, I continue to read, research, listen, and learn. Thus, the impetus for Clean & Lean.

One of my faithful followers messaged me about using my most recent program, The Clean 20, with the concept of intermittent fasting. She had been doing it on her own and had found improved results, especially after hitting a plateau. At the same time, one of my best friends, Nazr Mohammed, a former NBA player, decided he wanted to try intermittent fasting in the form of time restricted eating, in which he ate only between the hours of noon and 8 p.m. He had heard of others doing this and they had found success.

I asked both of them questions and listened intently to their methods, challenges, and insights. Two very different people—a woman in her sixties on the verge of retirement and a former professional athlete who had spent the vast majority of his life training and eating for peak performance—trying a similar eating strategy. I learned a significant amount and that led me to plunge into the available research of intermittent fasting, its benefits, strategies, and effects not just on weight, but on other important health biomarkers.

Intermittent fasting, while not heavily researched in humans yet, has shown promise in animal studies and via anecdotal evidence in humans. Clean eating, the basis of my last book, The Clean 20, has also shown particular benefits not just on the scale (average of 10-pound weight loss in twenty days), but in lowering cholesterol levels, glucose levels, and blood pressure. So why not combine the two and see if the benefits would be synergistic? It made complete sense to do this, and from the standpoint of execution it was a strategy I felt most people would be able to follow long enough to get results and return to if they wanted to tune up their bodies at other times.

Regardless of how well created or executed, no one diet plan works for everyone. Our bodies are different in so many ways, from the way we metabolize certain foods to the way we accumulate fat and the way we lose it. But Clean & Lean is a program that I believe the vast majority of people will be able to follow to achieve measurable results. I’m trimming the fat (literally and figuratively) and getting right to the point so that this might be one of the simplest nutrition books you’ll ever follow. Get ready to welcome a new you in thirty days!

Ian K. Smith, M.D.

April 2019

Copyright © 2019 by Ian K. Smith, M.D.