QnA #1: What Is The Difference Between A Serving Size And A Portion Of Food?

I find it extremely informative (and sometimes really entertaining) to see what brings non-subscribing people to Fitness Mantra in this vast expanse of interlinked pages we call The Internet. Often it’s the “usual suspect” keywords like “starvation response” or “fiber one bars“. But sometimes it’ll be totally unrelated or distantly related searches like “fat babies” or even “simpson doughnut“!

In most of the cases - particularly where I have written specifically about the keyword that the user searched for - I am pretty certain the user found what he/she was looking for. But sometimes I find that the user stumbles on one of my posts by asking an actual question on a Search Engine which I have not directly answered. Maybe the post had some of the keywords used in the question, but not in the context intended and so the user might be disappointed with the results.

While I don’t think I can answer every single question that users ask on the web and land up on this site, I thought it might be useful to begin a series of Questions and Answers or “QnA” (a new category, now). These will feature questions I see in the site logs and which I believe may not have been adequately answered until now.

So, without further ado, here’s the first QnA …

What Is The Difference Between A Serving Size And A Portion Of Food?

The short answer is that a Serving Size is a convenient quantity of food that the manufacturer has chosen in order to describe the nutritional value of that food, whereas a Portion is the amount of that food that you choose to eat at one sitting. These may or may not be the same depending on what food you are consuming.

The best way to describe this difference is with an illustration using one of the most recognizable foods around: A 20 oz bottle of soda (Nutrition Information obtained from the Pepsi Product Info page):

I chose this product primarily because it’s a perfect example of Unit Bias, the tendency to assume that a reasonably sized package of food is the right amount to eat at a time. Take a look at the the Nutrition Label, and the difference between Serving Size and Portion will become clear.

The FDA regulates what a serving size for a particular food is and in the case of sodas, they have decided that it should be 8 fl oz. Note that your own requirements may vary depending on how old you are or what your specific calorific needs are. So, while the FDA thinks that 2.5 “regular”(2000-calorie-a-day) people can drink from this one bottle, that may or may not be the case for you. The quantity you choose to drink, then, becomes your portion. On a hot summer day, if you’ve been walking about for a long time, you might decide to drink an entire bottle; on the other hand if you are just relaxing at home in front of the television, you might choose to share the bottle with someone.

In other words, while portions may vary from person to person (or even from time to time for the same person!), serving sizes are constant and are simply an FDA-recommended quantity to consume or the manufacturer’s quantity used to display nutrition information.

The good news is that many manufacturers also list the calorific information for the entire package alongside the single-serving information (they are not always required to do this, but sometimes do so when there is the chance that buyers might consume the whole product at one sitting). You can see this in the “Per Container” section of the Nutrition label pictured above.

Always remember that you need to adjust the calories and other nutrition information depending on how much (i.e. how many servings) of the product you decide to consume. In the case of the Pepsi bottle, sticking to 8 fl oz will mean 100 calories and 28g of sugar. Think that’s too much sugar? If you finish the whole bottle, that’s 69g of sugar!

So, to conclude, just read the serving size and watch your portions. You’ll do just fine!

[tags]health, nutrition, serving size, portions[/tags]