I started at the Art Gallery Sandwich Shoppe, 1712 I St. NW. Mona Lisa smirked at me from the menu as I instructed the waitress that I would like my tuna rinsed of oil. Maybe the kitchen did and maybe it didn't go so far, but it did deliver to me a whole -- though small -- can of tuna drained and unadorned, as I asked, by anything but a bed of lettuce and a green pepper ring for a dash of color the cook could not resist. Another day I might have had freshly roasted turkey or cold meat. If I had had the menu's regular tuna platter, it would have come with cottage cheese, tomato, hard boiled egg, celery and roll, and cost $3.75. Unadorned, it cost $2.50. Each of the few bites tasted wonderful, hungry as I was, washed down with club soda (40 cents) and coffee (40 cents). Usually the restaurant has fresh fruit -- apples, oranges, pears -- but that day the supply was gone. So I saved the fruit calories for a snack to buy on the street and left moderately hungry but able to look the poster of Famous Amos and his cookies straight in the eye as I left.

Another tuna lunch turned into no lunch. Rothschild Cafeteria, 1030 15th St. NW, served tuna already mixed with mayonnaise.Pleading for plain tuna brought the response that the mayo-tuna was perfectly acceptable as a weight-watcher's plate. No alternative, I drank iced tea (without sugar) and ate my emergency can of tuna at my desk later.