Q: I want to upgrade my potassium intake. I know bananas contain it, but are there any other foods that have a lot of potassium?

A: Indeed there are. Just by eating more fruits and vegetables you will add greatly to your potassium intake. Because some sources are better than others, we'll give you a few numbers to guide you:

A cup of winter squash is high on the list, with nearly 900 milligrams. There are between 700 and 800 mg. in a cup of either black-eyed peas or limas, or a baked potato if eaten with the skin. You would get 400-500 mg. of potassium from a quarter-cup of dried apricots, a banana, a quarter of a small cantaloupe, a cup of orange juice, a cup of chopped asparagus or Brussels sprouts, or a boiled potato.

Among those providing at least 300 mg. of potassium are a cup of grapefruit juice, a whole kiwi, a cup of sliced peaches, 5 large prunes, a cup of chopped broccoli, cooked cabbage, cauliflower or kale.

Q: In a recent column, you mentioned that one reason women do not get enough calcium is because they believe the calcium-rich foods are too high in calories. Can you point me in the direction of foods that contain calcium but are not overloaded with calories?

A: Perhaps the best bet for the calorie-conscious is skim milk. Two cups, containing just 180 calories, provide 80 percent of the day's Recommended Dietary Allowance of 800 milligrams. A reasonably close second is yogurt. One cup has 145 calories and contributes just over half the Recommended Dietary Allowance. The calcium-to-calorie ratio of some hard cheeses is better than others. Among the best are parmesan, romano, gruye`re and swiss. They provide anywhere from 107 to 117 calories and from 36 to 42 percent of the RDA for calcium. Other cheeses, in the caloric neighborhood -- including monterey, provolone, edam, and muenster -- provide about 25 percent of the calcium.

Remember that some vegetables contain appreciable calcium at a cost of very few calories. A large stalk of broccoli or a cup of cooked kale or collards has between 40 and 55 calories and will give you about 20 to 25 percent of the RDA.

Q: In a recent column, you wrote that research indicates that olive oil, rich in mono-unsaturates, seems to lower LDL ("bad" cholesterol) without lowering HDL ("good" cholesterol, the type associated with decreased risk of heart attacks). I was under the impression that much of the fat in meat is mono-unsaturated. Why doesn't it have the same effect?

A: It is true that meat has plenty of monos. Unfortunately, it is also rich in saturated fatty acids, which raise both total cholesterol and LDL cholesterol. Olive oil, on the other hand, contains mostly monos. As you point out, it appears to lower LDL cholesterol without lowering HDL cholesterol. And for that reason, it seems to make good sense to use olive oil, as well as other vegetable oils.

But this presents several practical problems. For one thing, olive oil is generally expensive. Most kinds are imported and supplies are limited. Besides, many people do not like its distinctive flavor. Peanut oil, the next best choice, contains only half as many monos.

One alternative rests in the hands of food manufacturers. It is possible to change the processing of other oils, such as safflower and sunflower, to make them rich in mono-unsaturates. And if research continues to support the benefits of increased monos, we will no doubt see some new oils at competitive prices.

Meantime, we cannot stress too strongly that variety and moderation are still the pillars of dietary efforts to control serum cholesterol. That means cutting down on total fat and saturated fat, and using oils rich in mono- and polyunsaturates in moderation.

1988, Washington Post Writers Group