A. For lunch, dinner, and snacks, the 21-Day diet permits limitless non-starchy veggies. Only lean meats, eggs, low-sodium veg burgers, berries, lemons, limes, non-starchy veggies (no potatoes or maise), legume-based kinds of pasta, quinoa, and brown rice are allowed. One of the most difficult aspects of this plan is no sodium-containing condiments or spices.