Keto Ultra Many diets ask you to eat unusual types or quantities of food. These can have a big effect on your budget, the amount of time you need to spend in the kitchen, or your travel time. If a diet wants you to rely heavily on food that's expensive or hard to get, there's a good chance it's not going to work well for you in the long run. Better diets will offer tasty recipes that don't take too long to cook and don't revolve around exotic foods.