DEAR DR. BLONZ: I am 5 feet 4 inches tall and weigh 110 pounds on a good day. My concern is that I have found that 1,000 calories is the most I can consume each day without becoming obese. This seems a bit under what I should be able to eat, but the scale has its persuasions, and I dislike letting myself go. I wonder how to determine an ideal body weight and daily calorie count. -- F.S., Scottsdale, Arizona

DEAR F.S.: The "ideal body weight" (IBW) was developed to help estimate how long it takes for drugs to be metabolized, which helps to determine appropriate doses of medications.

According to reference tables, an IBW for an adult of your height is between 97 and 127 pounds for females, and 114 and 143 pounds for males. Overweight is considered to start at 10% above a person's IBW, and obesity begins at least 20% above. At present, you show little risk of being overweight or obese. (For more information on ideal body weight in relation to height and age, see b.link/m6jdjc8.)

The 1,000-calorie daily limit you mention is on the low side for your height and weight. Consider discussing this concern with your health professional to rule out any metabolic issues, medications or other factors that may be at play.

What is a reasonable number of calories to consume every day? Estimates for an inactive adult are 10 calories per pound of body weight. A sedentary adult who is minimally active most of the day would need 13 to 14 calories per pound. An adult with a moderate activity level would need about 15 calories per pound of body weight, and very active adults need about 18 calories per pound.

These numbers are averages. The greater one's muscle mass, the more energy one needs -- even when just sitting around.

DEAR DR. BLONZ: I get nutrients, including protein and dietary fiber, from my daily use of 100% whole wheat bread. I like my bread toasted for breakfast and for sandwiches, and I wonder if there is a loss of nutrients when toasting bread. -- N.C., Raleigh, North Carolina

DEAR N.C.: The heat-sensitive vitamins include vitamins B1 (thiamine), B5 (pantothenic acid), B6 (pyridoxine), B9 (folic acid) and C (ascorbic acid), as well as some amino acids, which are the building blocks of protein. (Minerals are not affected by heat.) Lysine, an essential amino acid in grains, is an example of a nutrient that would be affected by toasting. Heat-sensitive nutrients are in grains but are more abundant in other foods. You might benefit from avoiding the toaster if toasted bread were your primary food, which it shouldn't be. There are plenty of other healthful foods to enjoy.

Take the amino acid lysine, for example, which comes mostly from animal proteins, soy and legumes. Heat has an impact, but the slight decrease of lysine in toasted bread is considered negligible. (For more on vitamins and their primary food sources, see b.link/pbq4rwb. For an explanation of the amino acids and their food sources, see b.link/9tc63kb.)

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 have shifted from animal sources to tofu as my primary source of protein. I am about 5 feet tall and I weigh 104 pounds. Is there anything about how tofu is made that I need to consider, and how much tofu should I have daily to satisfy my protein needs? I use tofu in a shake in the morning and add it to soups and salads. I scramble it, and I'm familiar with many other ways to prepare it. -- S.T., Tulsa, Oklahoma

DEAR S.T.: One serving of meat, poultry or fish is approximately 3 ounces, equivalent in size to a deck of playing cards. When trimmed of all visible fat, one serving would contain approximately 25 grams of protein. A cup of extra-firm tofu contains an equivalent amount of protein.

One way to estimate your recommended daily protein intake in grams per day is to multiply your weight in pounds by 0.36. A 104-pound body weight would require 37 grams of protein per day. (For more on protein recommendations, see b.link/hva5ju7.)

You indicate that tofu is your main protein source. Enjoying tofu is fine, but a single food should not serve as your dietary focus. Be sure to include other sources of protein. For vegetarians, these other sources might include nuts and seeds or a well-balanced diet containing grains and legumes, as these provide all the essential amino acids the body needs to make protein. For others, protein can come from fish, poultry and dairy, and red meat on occasion. The issue is not so much the source of the protein as the complement of other foods in the diet.

Tofu is made from soybeans that have been soaked, crushed, cooked and filtered. (For more on soybeans, see b.link/7y7jtya.) Calcium sulfate is then added, which causes the soy pulp to form a gel. The water is then removed as the soy is pressed into cakes. Tofu has a relatively high level of polyunsaturated fats, which can turn rancid when exposed to air -- especially warm air.

Fresh tofu must be packed in water and kept refrigerated. When purchasing fresh tofu, make sure it has been properly packaged and stored, and 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 package.

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

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: Do dried blueberries have the same antioxidant benefits as fresh ones? -- C.D., Albany, California

DEAR C.D.: Depending on the size and degree of hydration before harvest, a fresh blueberry is about 80% water by weight; a dried one is about 15% water (it may be less, depending on the degree of drying). With a dried berry, you get more nutrients and calories by weight (check the added sugars if they are sweetened). When dried, there will be a just slight loss of nutrients, but the loss of antioxidant substances is negligible -- nowhere near enough to dampen the flavor and nutritional value.

Dried blueberries are an excellent source of dietary fiber, and they contain the bountiful nutrients and beneficial phytochemicals found in fresh berries, so use fresh or dried -- whichever you prefer. I use fresh blueberries, preferably organic, in my morning breakfast, which includes plain whole-milk yogurt and a high-fiber granola.

When out of season, I rely on frozen blueberries. I always have dried fruits in the house, including cranberries, raisins, raspberries, cherries and blueberries, which I enjoy with various nuts (and a few dark chocolate chips) for my homemade trail mix, which also works as an office snack, allowing convenient access to flavorful, real food.

DEAR DR. BLONZ: One of my friends got his elevated cholesterol back in the desired range since he started taking a statin drug more than a year ago. Lately, however, he has become a bit lax in how he eats. Is there any reason, except perhaps for weight issues, why it would be best for him to stay away from foods that are high in cholesterol and fat if those statin pills keep his numbers in the good range? -- K.M.

Dear K.M.: I will offer general advice, as this is best discussed with a professional familiar with his family history and the specifics of his health situation. Medications prescribed to control an elevated blood cholesterol level should not be thought of as a license to eat and live in an unhealthful manner. Taking a statin or any cholesterol-lowering drug provides a means to correct a symptom of imbalance associated with an increased risk of disease.

Whether due to a genetic predisposition, poor diet or lifestyle factors, our blood cholesterol values become elevated for a reason. It makes little sense to think that a pharmaceutically lowered cholesterol level is the only fix needed. Such meds do not relieve us of the responsibility to treat our bodies with care. If you need the medication, by all means, use it. But wouldn't it be a worthy goal to make the appropriate changes to reduce or eliminate the need for the medication? (Read more about cholesterol in the blood at b.link/suaf5qb. See b.link/vq74z82 for an article on the impact of family history on heart disease and stroke.)

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.