DEAR DR. BLONZ: What is the latest thinking about the maxim that we should not eat fruits and vegetables at the same meal? For a longstanding myth, it certainly has taken its time to be soundly debunked. -- B.T., Tulsa, Oklahoma

DEAR B.T.: There is no one way of eating that works for everyone. We all have our quirks and twists on the physiological “rules” of the day, so what works for one might upset another. If there were to be a generalization in this matter, though, it would be that there is no evidence that fruits and vegetables need to be consumed separately.

The human digestive system is well-designed for mixed meals. Our body, however, does adjust to our eating habits, and radical shifts can lead to upset. This does not necessarily mean such a shift is a bad thing -- as long as it’s a change in a healthful direction -- but the issue may be the speed at which it’s instituted. If you are going to make changes, do so gradually.

DEAR DR. BLONZ: I understand there are beneficial ingredients in chocolate, including antioxidants. Are these substances found in the cocoa powder or in the cocoa fat? If it is in the fat, would that mean that the only way to get the benefits is to eat the full-fat kind of chocolate? -- C.H., Los Angeles

DEAR C.H.: Research on chocolate has indeed identified the presence of beneficial compounds. These compounds, known as flavonoids, have been found in the cocoa powder as well as the whole chocolate confection. Dark chocolate tends to contain more than milk chocolate; white chocolate, which contains cocoa butter (fat), contains little, if any, of the flavonoids. As for whether having cocoa powder is a “better” way of getting the benefits of the chocolate, that is a matter of personal preference. There are plenty of foods with wonderful attributes. Eat chocolate not because it is prescriptive, but because you enjoy it.

DEAR DR. BLONZ: I need your advice concerning a choice between psyllium husk (I take 4 teaspoons daily) and a new fiber supplement made from partially hydrolyzed guar gum. This new product is pleasant to take, nonthickening, has no grit and is flavor-free. But is it equally effective? -- I.K., Anderson, South Carolina

DEAR I.K.: There are many excellent whole-grain foods, fruits, and vegetables that are rich in nutrients and can provide the dietary fiber the body needs. If you have been instructed by your health professional to take a fiber supplement, either of these products will accomplish that goal. Pick whichever one you feel most comfortable with, and be sure to follow the label directions. And be sure to take it slow (see the first question, above), if this is a new component to your diet.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I am shifting to tofu instead of meat, but I want some guidance as to how much it will take to meet my protein requirements. I weigh 105 pounds and am 5 feet tall, and 1,000 calories is about as much as I can consume in a day without gaining weight. I want to have some idea of how much tofu I should have daily. -- R.V., via email

DEAR R.V.: As a general baseline, protein requirements for adults are about 3.6 grams of protein per 10 pounds of body weight -- so, multiply your weight in pounds times 0.36. Those routinely involved with intense physical activity may need twice that amount. The typical American, even if sedentary, tends to consume more than enough protein -- even above the level recommended for active adults.

One serving of meat is approximately 3 ounces, equivalent in size to a pack of playing cards. If trimmed of visible fat, this serving would contain around 25 grams of protein. One cup of extra-firm tofu contains an equivalent amount of protein.

I don’t think it wise for a single food to become the focus of any diet. Consider including vegetarian sources of protein such as nuts, seeds, grains and legumes -- or fish, poultry and dairy, if you are an omnivore. Red meat does not represent a health problem when part of a plant-based, whole-food diet. The issue is not so much its source as its place among the other foods you eat.

Concerning tofu, it is made from soybeans that are soaked, crushed, cooked and filtered. Calcium sulfate is typically added, causing the soy pulp to form a gel. The water is then removed as the soy is pressed into cakes. Tofu has a relatively high content of polyunsaturated fats, a type that can turn rancid when exposed to air -- especially warm air. If fresh, tofu should be kept refrigerated and in water. When you purchase fresh tofu, make sure it has been properly stored. You should take it home in a well-sealed plastic bag that contains water. There are other options, one of which is to buy cakes of tofu in refrigerated, commercially sealed, water-filled packages; another is to buy tofu that is vacuum-sealed in an aseptic carton.

Discard tofu if the storage water becomes cloudy, if a slippery film develops on the surface or if you notice any unusual smells. Also, the tofu should be discarded if it takes on a pinkish tinge -- usually the effect of exposure to air. If the water is changed daily, fresh tofu can last up to two weeks in the refrigerator.

Finally, a bit about your daily calorie comment. Checking the counter at b.link/calcounter reveals that your intake is on the light side for someone of your height and weight. A moderately active adult requires about 15 calories per pound of body weight; if that’s you, it translates to a daily caloric requirement of 1,575 calories. This suggests there might be room on your plate for more food. All these data come from population averages, so keep in mind that the greater your lean body (muscle) mass, the more energy it takes -- even if you are sitting around doing nothing.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I enjoy eating artichokes, but am skeptical of the claim I read that they can help cleanse the arteries. I would appreciate a comment about this. Also, are artichokes best if eaten raw or steamed? Is the expensive canned version just as healthy? How often should artichokes be eaten, and how much at a time? -- T.T., Walnut Creek, California

DEAR T.T.: This is a good time to be discussing artichokes, as spring is their peak season. The artichoke is in the same family as the sunflower and the thistle. The globe-shaped “vegetable” that we eat is actually the immature bud of a beautiful seven-inch purple flower. That helps explain why springtime, when flowers typically emerge, is when we see artichokes at farmers’ markets. (If you were planning to attend, the annual Artichoke Festival in Monterey, California -- where you can sample anything and everything artichoke -- has been postponed until August.) If left to bloom, the artichoke loses its appeal as a food, but the blossom can serve nicely as a table decoration.

Artichokes are not typically consumed raw, but are eaten after being steamed, boiled or baked, at which point they can be enjoyed hot or cold. Those that come canned are also excellent.

The artichoke is high in vitamin C and fiber, and is a good source of folate and magnesium. The artichoke plant contains several beneficial phytochemicals, some of which are antioxidants and others that may be of help to the liver.

One compound, cynarine, encourages the production of liver bile, which is used to emulsify ingested fats (lipids) during digestion. This plays a role in how we handle dietary cholesterol, but it’s not the same as “artery cleansing” -- no facts to back that claim. Another compound, silymarin, is a mixture of substances also found in milk thistle (an artichoke relative, as mentioned). It has been shown to have liver-protective properties, and the liver makes cholesterol when the body needs it. (Interesting side point: Even if we had no cholesterol in our diet, the liver would make all we needed.)

But it is important to understand that while the part of the artichoke that’s eaten may contain some phytochemicals, most tend to be found in the leaves of the plant. If a website mentions “evidence” to support a claim, be sure to check the source to see what part of the plant was used in the research.

How often should you eat artichokes, you ask? Let your palate be your guide. The artichoke does indeed have healthful attributes, but it is one player in what should be a grand cast of whole-food characters.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.