IN APRIL, fatsos planning to get in shape for summer were cheered by news that the drug industry was developing a diet pill that would, in effect, melt fat. No more counting calories or resisting ravioli--a capsule a day keeps the flab away. Well, here it is July. The pill isn't on the market yet, and all hope of squeezing into the bikini has been abandoned. The more resolute--or naive--among us are already thinking about a renewed effort--after Labor Day, of course--to get in shape for the holidays. Surely it will be easier to turn to tofu and tomato juice later in the year when cold beer and ice cream are not absolutely necessary for survival.

Those who have been waddling through the summer storing up calories for the new diet season were jostled out of complacency a few weeks ago by a series of television commercials advertising "starch blockers." Here is another pill that developers claim will prevent the digestion of starches and keep the weak- willed slim. Never mind that it is advertised in the same manner as vegetable slicers and tarnish removers, or that a dollar's worth of "bean derivative" was selling for $50. The pitch--"Eat bread, corn, even spaghetti without gaining an ounce"--was as irresistible as a double chocolate almond fudge with jimmies. Skeptics were reassured by the knowledge that any drug marketed in the United States has been analyzed, tested and certified safe and effective by the Food and Drug Administration. Right? Not quite. It seems that the pill's producers say the starch stopper isn't really a drug, just a food, so they hadn't even bothered to ask the feds for a seal of approval.

The FDA quickly put a halt to sales and did its best to spoil a few appetites with descriptions of the side effects of the product. While it's true that the pill prevents the digestion of starches, it doesn't seem to know what else to do with them. All that unabsorbed spaghetti just sits around the digestive system causing problems you don't even want to hear about.

Of course, it was too good to be true. Always is. Nutritionists tell us weight loss is hard; doctors tell us this method is neither safe nor effective; and even our own colleague, William Raspberry, points to the portentous moral implications of gluttony without guilt. Still, some of us will continue to dream. Just last week, for example, we heard about a former Ginsu knife salesman who is working on a tablet that will turn whipped cream into lettuce. Stay tuned.