This diet theory, consisting of 10% or less of daily calories from fat, is the flip-side to Atkins, Keto, and Paleo. Proponents of the ultra-low-fat approach adhere to a diet rich in plant foods, low in animal products, and high in carbohydrates (80% or more of daily caloric intake). An example of this type of theory is the TLC (Therapeutic Lifestyle Changes) Diet created by the National Heart, Lung, and Blood Association with the purpose of helping people combat heart disease, lower cholesterol levels, and prevent digestive problems.
Popularized by the documentary Forks Over Knives, the Ornish diet is a low-fat, plant-based diet plan based on whole grains, vegetables, fruits, and legumes. It's based on a lacto-ovo style of vegetarianism, allowing only egg whites and nonfat dairy products. It's packed with vitamins, fiber, and lots of filling plants to keep you satiated. Some studies have shown it can reverse heart disease and have beneficial effects on other chronic health conditions. (BTW, there is a difference between a vegan diet and a plant-based diet.)