It’s based on the theory that monounsaturated fatty acids, or MUFAs, target and destroy belly fat while promoting fullness and preventing overeating, according to the diet's creators, former Prevention magazine editor Liz Vaccariello and registered dietitian Cynthia Sass. These plant-based fats are found in foods like nuts, seeds, chocolate, avocados and olive oil – and the "Flat Belly Diet" (Rodale, 2008) calls for a precisely specified serving at every meal and snack. Unlike saturated fats, which harden and clog the arteries, MUFAs keep blood vessels soft and pliable after digestion. By following the Flat Belly Diet, it’s suggested, a person can drop up to 15 pounds in 32 days and lose several inches of belly fat. In addition to emphasizing these healthy fats, the Flat Belly Diet is modeled after a Mediterranean eating approach. The key ingredients – fruits, veggies, legumes, whole grains, olive oil and fish – are thought to help keep weight off.