What is the difference between a serving size and a portion size? Plenty.
A serving size is a specific measure of a food. A portion is the amount of that food that happens to be on my plate.
Why should we care? Understanding serving sizes can help us manage weight.
For example, one serving of milk is defined by nutrition experts as 8 ounces or one cup. Two cups (16 ounces) would be two servings. More ounces would be more servings.
Most adults need two servings or two cups of a calcium-rich food such as milk, yogurt or fortified soy beverage every day for optimal health. On the other hand, a portion of milk -- what one actually consumes at a meal -- might be a whole other animal.
Case in point: On a recent road trip, we stopped at a popular restaurant for breakfast. I ordered a glass of milk with my meal.
"Do you want the medium or large size?" the waiter asked.
After thinking it somewhat odd that "small" was not even an option, I asked, "How big is the medium?"
"Sixteen ounces," she said. "And the large is 32 ounces."
So a medium portion at this restaurant provides two servings of milk -- my daily quota.
And the belly busting 32 ounces -- a quart -- could easily feed a family of four.
Why does this matter? Large portions add nutrients and they also add calories. One cup (8 ounces) of low-fat milk, for example, contains about 300 milligrams of calcium, 120 calories and as much protein as an egg. A 32-ounce portion weighs in at a day's supply of calcium and close to a daily quota for protein -- and almost 500 calories.
We need to know the difference.
Not that we always have to consume standardized serving sizes. I just need to know that -- if I consume a 16-ounce portion of milk -- I have met my daily goal of two servings of a high-calcium food. I don't need to take in even more calories in an unnecessary quest to get more calcium.
Nutrition guidelines also tell us to consume two or three servings of a protein-rich food each day. And this recommendation comes with the understanding that one serving is equivalent to 3 ounces of cooked meat, fish, tofu, poultry or the like. However, Mr. Bodybuilder might eat a 12-ounce portion of steak which -- in nutrition terms -- equates to four servings. More than even a bodybuilder needs.
What it adds up is this: If we understand serving sizes, we can figure out how the actual portions we eat stack up to recommendations for optimal health (and weight). Here's one good source to help with that: choosemyplate.gov.
Barbara Quinn, a registered dietitian and certified diabetes educator, is the author of Quinn-Essential Nutrition (Westbow Press, 2015).
ActiveStyle on 05/23/2016