Q: Are vegetables more nutritious when cooked or raw?

A: Some nutrients, like beta-carotene (which forms vitamin A), are not damaged by heat. In fact, a recent study in the Journal of Nutrition noted that heat actually makes it up to six times easier for the body to absorb and utilize beta-carotene. Cooking does not seem to be a problem for most of the health-promoting phytochemicals in vegetables. But cooking does reduce the level of certain nutrients like vitamin C and folate. That’s why it’s better to briefly microwave, steam, or stir-fry vegetables rather than boil them for extended periods. The single most important thing about vegetables, however, is to eat them in abundance. The American Institute for Cancer Research (AICR) estimates that we can lower our risk for cancer by 20 percent if we eat at least five servings of fruits and vegetables each day. Make fruit and vegetables part of every meal.

Q: How can I choose the most healthful cereal?

A: The key is to choose a cereal that best meets your individual needs. Most Americans are getting only about half the recommended amount of dietary fiber, and cereal can be a good source. Choose one with at least three grams of fiber per serving, more if possible. If you’re devoted to a low-fiber favorite, try combining it with a higher fiber bran or whole-grain choice. Some high-fiber cereals are very low in sugar, while others contain a great deal. Remember that experts caution against excess sugar, so consider how much you consume throughout a day when choosing a sweetened cereal. You can choose an unsweetened cereal and add just a bit of table sugar to taste. You may want a cereal fortified with Vitamin B12, folate, and other nutrients. But, considering other foods eaten throughout the day, there’s no reason to choose a cereal just because it has more of every possible vitamin. Finally, if you’re watching your weight, it’s best to avoid cereals that pack a high calorie or fat content. And don’t forget to note the serving size listed in the Nutrition Facts panel.

Q: Is popcorn a good snack for people trying to watch their weight?

A: Popcorn can be a great high-fiber snack if you choose a low-fat type and watch your portion size. Microwave popcorn products come in a wide range of fat content and usually contain hydrogenated vegetable oils. To control overall fat content and minimize trans fatty acids, find the lowest-fat version that tastes good to you. Ideally, that will be one with no more than three grams of fat per serving. If you are salt-sensitive or have high blood pressure, you’ll want to check the sodium content, too. If weight control is your goal, watch your portion size. The calorie and fat content listed on the label is for a three- or four-cup serving. To make sure you’re not eating more than one serving, measure that amount into a bowl. If you won’t be sharing with others and don’t like leftovers, consider the “snack size” packages. Or, consider popping corn with an automatic popper or on the stove, using a bit of vegetable oil, which only takes a few minutes.

Q: What are these “smoothie” drinks I’m hearing about? Are they really healthy?

A: A smoothie is basically a blended drink made of fruit and non-fat milk, soy milk, or yogurt. It is a good source of calcium, vitamins D and B, as well as the vitamins, minerals and phytochemicals in the particular fruit used. People often find that a smoothie satisfies their hunger longer than “junk food” snacks containing far more calories and fewer nutrients. A homemade smoothie made as above, even with a teaspoon of sugar added, totals only 200 to 250 calories, and has virtually no fat. But beware of commercially prepared smoothies, which often contain a great deal of sugar, use higher-fat ingredients, and serve huge portions that often total 600 to 700 calories and 10 to 14 grams of fat.

Q: I know olives are loaded with fat. Just how fattening are they?

A: It’s true about 80 percent of the calories in olives come from fat. But remember this type of fat does not raise blood cholesterol and does not appear to promote cancer development. The only concern about how “fattening” olives are is how it affects the overall calorie level. Whether green or black, olives average around five to six calories each, depending on size. Ten olives in a favorite dish may add great flavor without too many calories, but watch out if you mindlessly snack on half a jar of them. Also, be aware that those 10 olives might have 400 to 450 milligrams (mg) of sodium, which is almost a quarter of the recommended daily limit.