First, the food companies themselves are hooked on salt, sugar, and fat. Their relentless drive to achieve the greatest allure for the lowest possible cost has drawn them, inexorably, to these three ingredients time and time again. Sugar not only sweetens, it replaces more costly ingredients -- like tomatoes in ketchup -- to add bulk and texture. For little added expense a variety of fats can be slipped into food formulas to stimulate overeating and improve mouthfeel. And salt, barely more expensive than water, has miraculous powers to boost the appeal of processed food.
P. xxviii - xxix, Salt, Sugar, Fat: How the Food Giants Hooked Us.
I just started this today, and upon seeing these words in the introduction they seemed worth sharing. I've become something of a pure-foods guy in recent years, though I do have a weakness for peanut butter and graham crackers. So far this book is making a decision to abandon processed foods completely look more and more attractive.