DEAR DR. BLONZ: I have been trying to cut back on my intake of meat and dairy. I have two young boys, and they are less than enthusiastic. I am wondering if my new vegetarian menu will provide them the protein they need. -- S.T., Arizona City, Arizona

DEAR S.T.: A semi-vegetarian menu, or one where there is no animal food whatsoever (vegan), can easily meet your family’s protein needs. It does depend, though, on which foods you include. You cannot simply eat plant foods without a plan and think you have things covered. A little background on protein may be of assistance.

First, there’s no question that proteins are important in the scheme of things; they are used to make hair, skin, nails, muscles, organs, blood cells, bones, brain and nerve tissue, enzymes, hormones, antibodies, chemical messengers and the DNA and RNA used to form the genetic code of life. Quite a lineup.

While there are different types of protein, they are all made up of the same amino acid building blocks. Our bodies can synthesize many amino acids on their own, but there are some we cannot make, and these have to be supplied by our diets. The ones we need are referred to as the “essential amino acids” (EAAs).

Most foods have some amino acids. Animal proteins, such as meat, fish, eggs and dairy products, are called complete proteins because they usually contain all the EAAs. Vegetable proteins, such as grains and legumes, are considered to be incomplete proteins because they’re missing, or are very low in, one or more EAAs. Soy protein is one exception, in that it is a complete vegetable protein. Vegetarianism revolves around the fact that one can easily meet their daily protein requirement by combining plant foods in a way that provides all the EAAs the body needs.

There are three basic types of vegetable protein: whole grains, such as rice, corn, oats and barley; legumes, such as beans and lentils; and nuts and seeds, such as almonds, sunflower seeds and sesame seeds. By planning the meals for the day to include foods from two or more of these groups, you end up creating a complete protein. For example, by eating rice (grains) and beans (legumes), you supply the body with the EAAs it needs to make its protein. Please note that these complementary foods do not have to be eaten at the same meal.

There is an excellent source page on vegetarianism at the National Library of Medicine, and it includes links to address issues for children and other groups. Find it at tinyurl.com/yd6hzh2a.

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 want some perspective on a recipe known as “skinny soup,” which consists of cabbage, celery, onions, garlic, peppers, carrots, canned tomatoes and water. The rumor is that digesting this soup uses more calories than those found in the ingredients. It is also supposed to be anti-inflammatory. There are many different spins on this theme online, with an assortment of recipes out there. Any truth to this? -- C.N., Phoenix

DEAR C.N.: Small amounts of energy are indeed required for digestion, as well as for the conversion of proteins, carbohydrates and fats into different forms and structures. And our bodies’ metabolisms are not 100 percent energy-efficient; energy is lost, perceived by us as heat when our metabolism kicks into a higher gear. (Think about the heat you experience while exercising.) This also occurs during the digestive process after eating, a phenomenon referred to as the thermic effect of food, or TEF.

It is all part of the cost of bodily business. Once the body is in a “fed” state, the green light goes on to build, repair and put the excess away into storage; these are also functions that require energy, but are not 100 percent energy-efficient.

Foods with a low caloric density (few calories per unit weight), such as that soup, might indeed cause the body to burn more calories than they provide. The caloric difference, however, would not be that significant. However, if you get in the habit of substituting a low-calorie soup or salad -- or even a glass of water or a cup of tea -- for a more calorie-dense food, the net effects will certainly add up over time. That’s the real skinny. It’s not a magic soup; it’s just math.

As for the anti-inflammatory aspects, contributions to that element of the balance sheet would hold true for the healthful whole foods in the recipe -- as well as most other fruits, vegetables and whole grains, however they are consumed.

DEAR DR. BLONZ: This is another exceedingly hot summer, and as we all know, summer temperatures tend to soften fruits rather quickly. I have hesitated to refrigerate tomatoes for fear it would result in a loss of flavor. Is this a misconception, or should I go ahead and refrigerate? -- F.M., Hayward, California

DEAR F.M.: Refrigeration can slow the growth of many microorganisms, but it can also affect the quality of some foods. Tomatoes are best kept at room temperature, preferably in an airy location with moderate humidity. They should last about five or six days in these conditions. By placing the tomato in the refrigerator, you may delay it from going moldy, but flavor and texture are likely to be damaged in the process.

This is particularly an issue with flavorful homegrown varieties and those purchased at a farmers market. It may not be as much of an issue with store-bought tomatoes that have already been given a dose of refrigeration, as many markets store their produce in the cooler overnight.

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: Our new home has some olive trees that are bearing fruit. We all know how healthy extra-virgin olive oil is for us, but do we get the same health benefits from eating olives? -- J.T., San Jose, California

DEAR J.T.: As you may have inadvertently discovered if you sampled the fruit, olives are quite bitter coming off the tree. To be eaten, they need to undergo a curing process to remove this bitterness, caused primarily by a phytochemical called oleuropein.

Curing typically involves a solution of salt or lye (sodium hydroxide). Both of these leave the olives quite high in sodium: 15 grams of olives (three to five of them, depending on size) contains about 115 milligrams of sodium -- not surprising given that the olives are stored in salty pickling brine before purchase. In a pimento-stuffed olive, the sodium can be twice that amount.

By contrast, when olives are used for oil, the harvested fruit goes directly to the presses without treatment. The fatty acid profiles are similar between eating olives and extra-virgin olive oil. The phytochemicals are mostly similar, with one exception being the intentional decrease of the bitter oleuropein in the eating olive.

It takes a lot of olives to equal a comparable serving of oil. For example, a tablespoon of olive oil (about 14 grams) would contain 120 calories. It would take about 22 large black-pitted olives to match that amount of oil, but that number of olives would contain 644 milligrams of sodium.

I do enjoy eating olives, and there are countless varieties and flavors, but you have to keep in mind that it’s a high-sodium food. You can give your olives a series of fresh-water rinses before serving to reduce the level of sodium.

If you are interested in this topic, there is excellent information from the University of California at Davis (tinyurl.com/zeqp2lh). This page provides reading on different olive types, the curing process, and information on curing with water, which would certainly make a dent in the level of sodium.

DEAR DR. BLONZ: I’ve been having a strange reaction to all dairy, including lactose-free products. I react as if I’ve had three cups of coffee or other caffeine products. I cannot sleep, and sometimes I get a headache. What am I allergic to? -- T.M., via email

DEAR T.M.: Get this checked out with your health professional at your earliest opportunity. It could be a reaction to the protein or some other substance found in dairy products -- but whatever the issue might be, this is NOT something you should let slide. Until it is all sorted out, it’s best to keep dairy products off the menu. This includes reading the ingredient statements of any processed foods you use. There are many dairy ingredients aside from the obvious; see the hidden dairy “cheat sheet” at tinyurl.com/y9tmbw75.

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.