The best way to develop a sharp eye for accurate serving sizes is to practice measuring foods at home. For one week, diligently use your cup measures, tablespoons, and kitchen scale to precisely portion out single serving sizes as listed on the nutrition label. After a week of consistent measuring, you will have a good feel for true serving sizes, at least in the dishes in your home.
So what do you do for quick reference when eating at a friend's house, or at a restaurant with unfamiliar dishes and gargantuan meals? If you lack precision portion sense and don’t feel like carrying a set of measuring cups and spoons in your purse, there are some common household items to help you gauge portion sizes.
An 8 oz. or 1 cup serving is about the size of a baseball, or a woman’s fist. A cup is a serving of most fruits and vegetables (a brain-sized grapefruit is really two servings even though it is a single piece of fruit). A cup is also a single serving of most beverages including milk and soda. A cup of salad greens would fill the space in two cupped hands.
A ½ cup serving, such as cooked pasta, rice, cereal, mashed potatoes, ice cream, or yogurt is about the size of a rounded handful, a hockey puck, a tennis ball, or a light bulb.
A golf ball or small egg represent the volume of a ¼ cup--the recommended serving of nuts or dried fruit.
Most salad dressings and peanut butters list their serving size as two teaspoons, about the size of half an egg or golf ball.
A single teaspoon, such as a pat of butter or the mayonnaise on a sandwich, should fit underneath a poker chip.
According to the USDA food pyramid, a serving of fat such as oil, butter, or salad dressing is 1 teaspoon, which is about the size of two stacked nickels or the tip of your thumb.
Foods Beyond Measure
A restaurant baked potato is typically twice the size of a small spud, which is one serving. A good comparison is a computer mouse or a light bulb. If you can’t imagine fitting your potato into a light socket, it’s probably more than one serving.
A single serving sized pancake is only as wide as a CD, so a triple stack of plate-filling flapjacks the size of your face is probably about six servings, not three.
A slice of bread should be a little bigger than a cassette tape, and a small bagel (one serving) no bigger than a can of tuna.
Three dice are a good comparison for a 1 ½ oz. serving of hard cheeses like cheddar.
To keep indulgences in check, use dental floss: a box of dental floss is the same size as an ounce of chocolate or a 2-inch square brownie.