Calculating the Correct Amount of Protein You Need

As a general rule, the National Academy of Sciences says healthy people need to get 10 to 35 percent of their daily calories from protein. More specifically, the Academy has set a Dietary Reference Intake (DRI) of 45 grams protein per day for a healthy woman and 52 grams per day for a healthy man. (Check out Chapter 4 for a complete explanation of the DRI.)

These amounts are easily obtained from two to three 3-ounce servings of lean meat, fish, or poultry (21 grams each). Vegetarians can get their protein from 2 eggs (12–16 grams), 2 slices of prepacked fat-free cheese (10 grams), 4 slices of bread (3 grams each), and one cup of yogurt (10 grams). As you grow older, you synthesize new proteins less efficiently, so your muscle mass (protein tissue) diminishes while your fat content stays the same or rises.

This change is why some folks erroneously believe that muscle “turns to fat” in old age. Of course, you still use protein to build new tissue, including hair, skin, and nails, which continue to grow until you cross over into The Great Beyond. By the way, the idea that nails continue to grow after death — a staple of shock movies and horror comics — arises from the fact that after death, tissue around the nails shrinks, making a corpse’s nails simply look longer. Who else would let you in on these secrets?