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 email@example.com. Due to the volume of mail, personal replies cannot be provided.