It takes quite a bit of produce to make enough juice to substitute meals. Not a ridiculous amount, but you do need to prep. The trade-off is that even though there is some clean up, you do not clean pots or pans, or the stove etc. Basically you just clean the juicer and the bowls. But for me I drink about 4 glasses per 'meal', and if I do that I am not hungry.
This morning I juiced 4 apples, 3 oranges and a handful of strawberries. It took about 45 minutes from start to finish, including clean up. That yielded 4 each 10 oz glasses of juice that I drank until about 11.