Ask Tufts Experts

In your article “Eating for Endurance,” you state that plant proteins are incomplete proteins with the exception of soy protein. I thought quinoa supplied all the essential amino acids. Isn’t quinoa a complete protein grain?

Actually, neither soy nor quinoa—which is technically a seed, but is cooked like a grain—is a “complete protein” in the sense of delivering as much of all essential amino acids as do animal options such as beef, milk or eggs. Quinoa and soy, as well as wheat, are very good protein sources and deliver at least some percentage of all the amino acids your body needs. But plant proteins, including these three, fall short of beef in their share of certain amino acids. Coupled with beans or another complementary protein source, however, quinoa delivers a complete package of protein. Quinoa also contains more iron than most grains, and provides some calcium, phosphorus, folate and B vitamins. No wonder the Incas called quinoa “the mother grain”!

Is there a chart of daily food allowances for people over 80 years old?

We’ve received a number of questions along this line, wondering about dietary data specifically for older adults. If you have access to the Internet and the free Adobe Acrobat Reader software, you can view a complete chart of Dietary Reference Intakes (DRI) established by the Institute of Medicine. This chart breaks out daily dietary needs by gender and age, including categories for males and females ages 70-plus. You can also go to the Web site for the new federal dietary pyramid at MyPyramid.gov, enter your age, gender and typical exercise level, and receive a customized version of the pyramid, including a complete eating plan.

You’re correct in thinking that dietary needs change with age. Although the recommended intakes for many vitamins and nutrients are the same for all adults, the adult DRIs increase with age for vitamins including C, D, K and B6 as well as calcium. Your need for some minerals actually decreases with age—notably iron (for males after 18 and females after 50), chromium, phosphorus (after age 18), sodium and chloride. But don’t worry too much about the numbers—in general, if you eat a balanced, varied diet like that spelled out by MyPyramid, you’l get most of the nutrients you need, whatever your age.