Depending on the definition of "sustainable," the easiest diet plan to sustain or stick with is Weight Watchers, according to a 2015 article on U.S.News.com. EatingBetter.org describes a sustainable diet as one which has a low environmental impact with healthy, accessible and affordable food.
U.S. News Health rated several diet plans on the basis of user friendliness, whether they were filling and tasty, and types of food required. Weight Watchers ranked number one as being the most flexible, since no foods are forbidden, even occasional treats, so long as dieters stick within allotted food points. Flexible support meetings and realistic goals also contributed to the score. The only cons for Weight Watchers were having to keep track of points and the cost. Prices vary during the year but are around 20 dollars for registration and 20 dollars a month to maintain membership.
EatingBetter.org gives several tips for eating a sustainable diet. These include eating less meat and more fruits and vegetables, wasting less food, eating less processed food and purchasing food that is certified as sustainably grown. Buying locally grown, seasonal and organic food is also recommended as is home gardening.