Over the last century, countless doctors and nutritionists have advised people looking to lose weight to “eat less and move more.” Sure, many other popular diet approaches (hello, low-fat, low-carb and keto) have cycled from fad to foe to fad again, but the reigning belief has long been that anyone who is serious about slimming down can, if they simply shrink their portion sizes and hit the gym more often. Yet as straightforward as that solution seems, waistlines have steadily swelled year after year. According to the Centers for Disease Control and Prevention (CDC), an estimated 42% of adults and 20% of children and adolescents in the United States struggle with obesity (as well as health issues, including a heightened risk of type 2 diabetes, heart disease and some cancers that come along with the excess pounds). Inside these pages learn the hard science to weight loss, armed with this knowledge you are sure to reach your goals and more!