It depends mostly on you and your particular situation, because the Daily Dozen’s guideline of 18 servings across 10 food groups is a recommended daily minimum.
Many people will need to eat more: e.g. if you’re physically active, or have more lean muscle mass, or male, or have a higher metabolic rate, etc. you’ll need more food to maintain or gain weight. On the other hand, if you want to lose weight, the Daily Dozen’s 18 servings of nutrient-dense food could suit you well, providing the variety, nutrition, and feelings of fullness and satiety you need to stick to the program. Be sure to consult with a plant-based dietitian (RD or RDN degree) or clinician (PA, NP, MD) to get proper individualized advice.
With LeafSide you have the option to easily complete the Daily Dozen’s minimum recommended servings, by eating one sweet meal and one savory meal, which provides roughly 1300-1500 calories. For most people that leaves room for a 3rd meal, or healthy snacks like fruits. If you want a lot more calories, you can easily get more by eating nutrient-dense and calorie-dense whole foods like sprouted-grain bread and other whole grains products; hummus or a bean salad; nut or seed butters; fruits; sweet potatoes, and so on.