Recently my family went out to a restaurant for brunch. I ordered a glass of milk with my meal. The waitress asked if I wanted a medium or large size.  (There was no small option.)  I asked how big the medium and large sizes were; medium was 16 ounces and large was 32 ounces.

When it comes to food, dietitians’ brains are always calculating, and I immediately knew that the medium milk portion offered provided two servings of milk – or 2/3 of my daily dairy quota.  This situation was a perfect example that often a serving size is not a portion size.  A serving size is a specific measure of a food. A portion is the amount of that food that happens to be on your plate.

A serving of milk is defined by health experts as 1 cup, which equals 8 ounces. Adults need two to three servings of a calcium-rich food such as milk, cheese or yogurt every day for optimal health. On the other hand, a portion of milk – what one actually consumes at a meal –  can be a whole other story.

So what’s the big deal?  Why should it matter?  Because understanding serving sizes is a major key to helping manage our nation’s growing waistline.

Nutrition guidelines recommend having two servings of a protein-rich food each day. This advice comes with the understanding that one serving is 3-4 ounces of cooked meat, fish, poultry, tofu or other protein equivalent.  But some athletes might eat a 12-ounce portion of meat, which equates to three servings.

So here’s how it works.   If you understand serving sizes, you can figure out how the actual portions you eat measure up to recommendations for optimal health and weight.  My favorite go-to source is:

And a few more tips:

  1. Learn to order smaller portions.
  2. Ask about half portions, choose from the child’s menu, or order appetizers instead of entrees – often they are serving size.
  3. If you order a full portion, box up half of it before you begin eating.
  4. Split an entrée with someone else

And use this mantra:

  • S = serving and is a specific amount
  • P = portion and is what people give you