I cook for one and have 14 robust garlic plants. If I harvest one leaf from each cyclically (i.e. once every two weeks) will this depreciate bulb growth?
I don't think it's going to hurt the bulbs if you don't harvest too vigorously (especially if you take off the scape before it flowers), but you probably won't be able to harvest continually throughout the season without killing the plant or making it go dormant. Garlic only seems to grow so many leaves each year, and pruning doesn't help it grow more. You can pretty much only expect one good harvest of the leaves if you harvest them all at once and let them grow back. I'm not sure about if you harvest one leaf at a time--but the leaves get tougher later in the season (it's best to harvest the leaves while they're reasonably soft and young, whether or not they're full-sized; they get more fibrous somewhere around the time the scape is developing, in my garden).
If you want your garlic to grow a scape and flower, I don't recommend harvesting any leaves. It'll still do it, if you let it, but I don't recommend it.
If you want a lot of garlic-tasting leaves that you ought to be able to harvest more often, I recommend growing garlic chives (Allium tuberosum).