Sandra Woodruff, RD Responds:

Sandra Woodruff, RD, a nutrition consultant and author of several cookbooks, responds: Comparing foods to common household items can make visualizing proper portion sizes easier. Here are a few tricks to help out. 

Three ounces of red meat, fish, or poultry—a standard portion—is about the size of a flip-style cell phone.

One cup of vegetables or an average portion of fruit is about the size of a tennis ball.

One ounce of cheese is about the size of four dice.

A medium baked potato is about the size of a computer mouse.

One teaspoon of butter is about the size of a postage stamp.

One ounce of peanut butter is about the size of a roll of film. Take a look at your meals with these visual cues in mind. You might find that there's far more on your plate than you realized.