I LoveCountry Cafe   At these restaurants popular with athletes, bodybuilders and others who closely watch their diets, you can get anything from a virtually fatless vegetarian meal to a standard, gravy-over-everything plate it's your call. The service is fast, the items are grilled to order, and there are numerous daily specials. The menu is typically local with lots of stir-fries and other Asian-style preparations. They cater, too.  Kakaako: 451 Piikoi St., 596-8108, 8 a.m.-9 p.m. daily. Pearl Harbor: Pearl Harbor Navy Exchange, 423-6555, 7 a.m.-9 p.m. daily. Kahala: Kahala Mall, 4211 Waialae Ave., 735-6965. 8 a.m.-8:30 p.m. Mondays-Thursdays, 8 a.m.-9 p.m. Fridays-Saturdays, 8 a.m.-8 p.m. Sundays. No reservations. AX, DC, DS, JCB, MC, VS. No checks. $.