Q. I read that it's recommended that we consume 25 to 30 grams of fiber a day. How do I estimate what I'm getting without becoming a slave to fiber tables and a calculator?

A. The best way to get enough fiber without resorting to mathematical calculations is to eat plenty of whole-grain breads and cereals, dried beans, vegetables, fruits, and -- if your weight allows it -- nuts. (Nuts are high in fiber, but are also concentrated sources of fat and therefore rich in calories.)

To be specific, four servings of fruits, four of whole-grain cereals and four of vegetables should provide all you need. That probably sounds like a lot, but remember that even though you might not eat four different types of vegetables in a day, the amount you consider a serving is probably larger than the serving size defined in food tables. For example, a 3/4-cup serving of broccoli yields 5 grams of fiber, but your serving could easily be twice that big. Similarly, half a small pear contains two grams of fiber, so if you eat a whole medium pear you'd get as much as 6 grams.

Simply by eating a variety of fiber-rich foods you'll get all you need and more. Bran cereals have 8 grams of fiber per ounce, which is about one-third of the recommended total. A 3/4-cup serving of bran flakes will give you 5 grams, or a shredded-wheat biscuit, 4 grams. Whole-grain breads are rich sources, too. A bran muffin provides 4 grams; two slices of whole-wheat bread or a whole-wheat bagel contains about 3 grams. A serving of brown rice has 3 grams.

With vegetables, just a half cup of cooked dried beans provides 9 grams or more, a half cup of spinach has 6 1/2 grams, and of peas or corn, 5 grams. As to fruit, a small-to-medium serving usually provides 3 to 4 grams, although some fruits have more. Two dried figs will give you over 7 grams of fiber, while a half cup of raspberries contains more than 9 grams. Among the nuts, an ounce of almonds provides 5 grams, compared to only half that much in the same amount of pecans or peanuts.

Clearly, by including a good mix of these foods in your diet, the figures will quickly add up to fill your fiber quota. It definitely makes sense to eat a wide variety of fiber-rich foods, since different types of "fractions" of fiber have different effects in the body.

Q. Since she was a teenager, my daughter has been a lacto-ovo vegetarian. But now she's in her twenties and pregnant. Is it still a good idea for her to avoid all meat?

A. There's no reason why she shouldn't be able to get all the nutrients she needs for a healthy pregnancy on a lacto-ovo vegetarian diet. Indeed, the basic recipe for success is simply to eat larger servings of the foods that have provided her with a nutritionally sound diet for a number of years.

For example, let's take calcium. She should be getting 1,200 milligrams a day, or about 50 percent more than that recommended for a woman her age who isn't expecting a child. Assuming that she normally drinks two cups of milk a day, all she must do is add one cup more, or perhaps a cup of yogurt, to bring her three-quarters of the way to her new goal. Add to that 2 ounces of hard cheese and she more than meets the 1,200-milligram target. Furthermore, she can count on foods like tofu (soybean curd) and green vegetables such as broccoli, collards, kale, mustard and turnip greens to provide some calcium, too. Almonds, sesame seeds and oranges also add to the total.

As you can see, if she's been doing well on her diet all these years she needn't alter it radically during pregnancy. All she has to do is to follow the guiding principle of eating larger servings of fruits, vegetables, whole grains, dried beans and seeds, and she'll meet her increased needs for calcium and for other nutrients as well.

Q. I recently read an article on diet that said it takes calories to digest food. How many does it take?

A. Digestion is just one step in the journey food makes from the mouth to the body's cells. The processes of absorption, transport, metabolism and storage all require energy, as do certain nutrient-related nervous-system functions.

Taken together, the energy needed for all these steps is referred to as the "thermic effect" of food, or TEF. Scientists haven't yet figured out all the factors that can affect TEF. It's estimated to represent about 10 percent of the day's caloric expenditure.