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The Met Flex Diet: Burn Better Fuel, Burn More Fat

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From #1 New York Times bestselling author Dr. Ian K. Smith, a powerful six-week plan to burn fat more efficiently by improving metabolic flexibility.

The human body has the amazing ability to switch which fuels it uses for energy based on what fuel is available at the time—researchers call this metabolic flexibility. Bodies that are able to make this switch can burn sugars, proteins, and other food nutrients when available, and then switch to burning the body’s fat storage or fatty acids when food calories are not available. It turns out that losing weight is not just about burning calories, it’s also about switching between these pathways as efficiently as possible. Yet little has been written about how to achieve metabolic flexibility—until now.

Dr. Ian K. Smith is a renowned medical expert and the author of numerous bestselling health books. In The Met Flex Diet, he offers a one-of-a-kind plan to improve metabolic flexibility through changing the types and quantities of food/beverages consumed, as well as the type of exercise. Timing is also a factor—timing of meals and timing of exercise relative to when the meals are consumed. All of these variables will play an important role in helping the body make the important switch from one fuel source to another.

In just six weeks, readers can experience amazing fat-burning results by following simple guidelines, like:


Eat the first meal of the day three hours after waking.
Complete a fasted cardio workout within the first two hours of waking.
Get at least seven hours of sleep a night.
Finish dinner two hours before going to sleep.
Complete with meal and exercise plans, as well as recipes, The Met Flex Diet gives readers every tool they need to meet their weight loss goals.


272 pages, Hardcover

Published April 4, 2023

156 people are currently reading
2583 people want to read

About the author

Ian K. Smith

48 books369 followers
Ian K. Smith, M.D.,Ian K. Smith, M.D. is the #1 New York Times bestselling author of SUPER SHRED, SHRED, THE 4 DAY DIET, THE FAT SMASH DIET and EXTREME FAT SMASH DIET among 7 other books including, SHRED Diet Cookbook , EAT, Happy , and The Blackbird Papers. His newest book, THE SHRED POWER CLEANSE, is available 12/29/15.

He is a former co-host of Emmy-winning “The Doctors” TV show, and a medical contributor to “The Rachael Ray Show."

He is the former medical correspondent for NBC News network and for NewsChannel 4 where he filed reports for NBC’s “Nightly News” and the “Today” show as well as WNBC’s various news broadcasts. He has appeared extensively on various broadcasts including “The Oprah Show,” “Good Morning America” “CBS This Morning” “The View,” “The Talk,” “Dr. Oz,” ‘Dr. Phil,” “Anderson Cooper 360″ and “Showbiz Tonight.”

He has written for various publications including Time, Newsweek, Men’s Health, and the New York Daily News, and has been featured in several other publications including, Publisher’s Weekly, Red Book, USA Today, Wall Street Journal, People, Essence, Ebony, University of Chicago Medicine on the Midway, Cosmopolitan, Women’s World, and Black Enterprise.

Dr. Smith is the founder of two major national health initiatives—the 50 Million Pound Challenge and the Makeover Mile—that have helped millions of people lose weight and improve their health.

A graduate of Harvard, Columbia, and the University of Chicago Pritzker School of Medicine, Dr. Smith was appointed to the President’s Council on Fitness, Sports, and Nutrition in 2010 and is serving a second term.

http://shredlife.com/about-shred/abou...
http://us.macmillan.com/author/ianksmith

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5 stars
23 (18%)
4 stars
26 (21%)
3 stars
43 (35%)
2 stars
24 (19%)
1 star
6 (4%)
Displaying 1 - 16 of 16 reviews
Profile Image for Ashley.
514 reviews15 followers
August 25, 2025
Buddy, intermittent fasting is not for those of us with hanger issues.
170 reviews3 followers
March 15, 2023
I received this book as part of a Goodreads giveaway.

This was an interesting read and I think a very well thought out and meticulous plan. Unfortunately for me I have some extenuating illnesses that will make it impossible for me to follow this plan. However, I do appreciate how detailed the plan is and that this book gives you a very strict plan to follow for those that need/can do that.
Profile Image for Kathy.
239 reviews3 followers
March 11, 2023
Got this book in the mail today and have already devoured it (no pun intended!). It has really simple explanations about metabolism and how to train your body to optimize metabolism. Best of all, it offers a simple plan with options and recipes to get you started on your weight loss/ healthy living journey. Can’t wait to try out these recipes!
Profile Image for Nikki Penda.
123 reviews3 followers
July 11, 2023
Why do I keep thinking I’m gonna learn anything from these books?… actually biggest reminder is WATER is your best friend ☺️
Profile Image for Online Eccentric Librarian.
3,400 reviews5 followers
February 13, 2023
More reviews at the Online Eccentric Librarian http://surrealtalvi.wordpress.com/

More reviews (and no fluff) on the blog http://surrealtalvi.wordpress.com/

I'm done with these celebrity non practicing doctors and their diet books. Once again, it feels like we have a book written because the author needs to keep his celebrity status going and bring in some extra dollars.

This one was just ridiculous. It's a keto diet redux suggesting that cheeseburgers, fries, chocolate covered almonds and multiple eggs fried in butter are a great way to eat - because hey, as long as you do intermittent fasting and heavy exercise with it, you'll lose weight! Worst, this plan requires that you follow it strictly and it is intricate: different types of fitness, number of carbs, and intermittent fasting routines depending on the day of the week. There are some recipes and brief discussions of some exercises - but e.g., you'll have to do strength, aerobic, and stretch routines depending on what day of the week of the plan (which changes up every few days).

So even if you get the weight off, it is coming right back as soon as you are done because no one can follow a tight routine from a book for the rest of their lives. The only suggestion for how to keep the weight off at the end (if you are still alive and haven't died of a heart attack) is to just do the program again. But at least you are allowed beer and alcohol!

There are a total of 3 scientific citations to support the efficacy and no evidence that the author actually practiced this with real individuals. At the end, the author pretty much says that he saw some studies on varying metabolic rates of the body and that must be the key to weight loss! So hey, we get to be the guinea pigs. I was completely disappointed and honestly kind of disgusted by the whole thing. At the end, this is just another yo-yo diet that doesn't fix the underlying causes of why you became obese in the first place. Reviewed from an advance reader copy provided by the publisher.
Profile Image for Michelle Ogden.
328 reviews8 followers
April 14, 2023
Have diet plans not worked for you in the past? Do you have metabolic syndrome? You may need to jump start or shock your body into action. The Met Flex Diet provides a detailed meal and exercise plan to do just that. If you are fed up with things not working and have the will power to follow this guide you will see some incredible results. Combining Keto, intermittent fasting, HIIT, weight training and low key cardio will have you feeling better than ever. You can sub out meals with the listed replacements too. But following each weekly plan is a must to shake up your metabolism and help it learn to be flexible.
Profile Image for Robban Fleege.
157 reviews3 followers
September 11, 2024
Good stuff on the biological metabolic process... the rest, not so good. Dont think we need more branded very specific plans. Maybe as a coaching models with supervision...but I think people buy these books - then have a hard to follow program week by week which harms results and then blame themselves... on to the next new shiny program.
25 reviews1 follower
July 1, 2023
Thank you to Goodreads and to the publisher for the ARC of this book.

This is a very well written and thought out book that provides a specific guide to those that are looking for a diet plan. It explains the thought process behind the plan as well as easy to follow tips and suggestions.
882 reviews66 followers
April 6, 2023
Interesting discussion about metabolism. Creative recipes.
Profile Image for Cooky Glenn.
3 reviews1 follower
April 11, 2023
healthy and maintainable

Great. Introduced new foods. At time did not feel I was ‘dieting’ just eating better and more filling foods. Yum.
472 reviews
May 31, 2023
detailed six week plan that is easy to follow for those who want to change their lifestyle
Profile Image for Joni Owens.
1,525 reviews10 followers
Want to read
June 13, 2023
I love Dr. Ian’s books. I find them easy to understand and follow. I think Met Flex is a great concept and I look forward to trying.
Profile Image for Tam.
20 reviews1 follower
October 8, 2023
Won this thru Goodreads. Interesting concept and some decent recipes. Wouldn’t be sustainable for me.
Profile Image for AMAO.
1,872 reviews46 followers
July 17, 2023
The Met Flex Diet: Burn Better Fuel, Burn More Fat by Ian K. Smith
Published April 4th 2023


Folks need to invest in an assistant or an ALEXA App to follow the complexity of these eating and exercise routines. It was way too many steps, rules and restrictions. It is not user friendly at all.
#TheMetFlexDiet #NetGalley



The human body has the amazing ability to switch which fuels it uses for energy based on what fuel is available at the time—researchers call this metabolic flexibility. Bodies that are able to make this switch can burn sugars, proteins, and other food nutrients when available, and then switch to burning the body's fat storage or fatty acids when food calories are not available. It turns out that losing weight is not just about burning calories, it's also about switching between these pathways as efficiently as possible. Yet little has been written about how to achieve metabolic flexibility—until now.

Dr. Ian K. Smith is a renowned medical expert and the author of numerous bestselling health books. In The Met Flex Diet, he offers a one-of-a-kind plan to improve metabolic flexibility through changing the types and quantities of food/beverages consumed, as well as the type of exercise. Timing is also a factor—timing of meals and timing of exercise relative to when the meals are consumed. All of these variables will play an important role in helping the body make the important switch from one fuel source to another.

In just six weeks, readers can experience amazing fat-burning results by following simple guidelines, like:

Eat the first meal of the day three hours after waking.
Complete a fasted cardio workout within the first two hours of waking.
Get at least seven hours of sleep a night.
Finish dinner two hours before going to sleep.
Complete with meal and exercise plans, as well as recipes, The Met Flex Diet gives readers every tool they need to meet their weight loss goals.
58 reviews2 followers
June 28, 2023
I really like this book. It's very clear to understand. It lays out 6 weeks of this diet plan from what to eat, drink, and other important details for each week. It also includes recipes and exercises, which is a great addition to have in this book. I look forward to completing these six weeks, and I will update this review once I finish them.

Update: I followed this plan at about 95% and lost 10 pounds. I love this book!
Displaying 1 - 16 of 16 reviews

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