Although metabolism is still not fully understood, its implications for how we gain and lose weight and its impact on our overall health have never been more important in our need to prevent and identify causes for various conditions. In fact:-The National Center for Advancing Translational Sciencesc urrently recognizes more than 500 metabolic disorders.-A 2019 seminal study on metabolic health published by researchers from the University of North Carolina at Chapel Hill found that only 12 percent (one out of eight) of US adults have optimal metabolic health. But where there's a challenge, there's also tremendous opportunity. In response, a science based "Met Flex" (short for Metabolic flexibility) program from #1 New York Times bestselling author and Harvard alum Dr.Ian Smith is publishing on April 4, 2023 from HarperCollins/Harvest. Dr. Ian says, "After very quickly learning the definition and physiologic underpinning of this term, I thought about those carb statements I'd been hearing for years but never fully understood. Metabolic flexibility addresses the body's ability (or inability) to switch from burning carbs to burning fats and vice versa. I had one of those eureka moments as the last twist of the bulb finally turned on the light in my brain. What all of these people (and I'm sure millions of others) have been feeling and describing is a state of metabolic inflexibility....with this six-week program, you become your own mechanic." Dr. Ian shares how what we have largely believed to be indisputable facts about metabolism have been refuted in the Journal of Science ("Daily Energy Expenditure through the Human Life Course";August 2021). The major findings include that the belief that all of our metabolisms start to slow down at 30 is not true. Rather we have FOUR life stages of metabolism that highlight:-people between ages 20-60 generally have stable metabolisms-there aren't really any differences between men/women when you control for size/muscle.