There is a disconnect between the USDA dietary recommendations and the dietary habits of Americans. The Dose Makes the Poison proposes that the solution to this disconnect is an approach that involves setting daily calorie and nutrient goals that we follow as if they were a budget. We can spend our budget however we want; eating fruit and vegetables is like spending our budget on rent, while eating chips and ice cream is like spending our budget on a designer handbag.We know that energy balance trumps all when it comes to body weight. Calories in must exceed calories out to gain weight; calories out must exceed calories in to lose weight. What is seldom addressed, however, is that: 1.) we are not always logical, rational beings who can follow seemingly simple nutrition advice; and 2.) our internal bodyweight regulation systems do not always act predictably. For these reasons, successful flexible dieting requires: 1.) external regulation of the diet by tracking dietary intake; and 2.) continuous monitoring and adjustments to ensure that we break through plateaus and that we can exit and re-enter our diets appropriately. The Dose Makes the Poison teaches readers how and why flexible dieting works while specifically addressing how to deal with the reality and the psychological impact of dieting.