Serving Size vs. Portion Size: How to Determine How Much to Eat

Raise your hand if this sounds familiar: you go out to a restaurant, excited to eat a chef-cooked meal and unwind from a difficult week. You order your favorite pasta dish that you make all the time at home. However, when your meal arrives, it’s such an enormous mountain of pasta that you wish you and your dining mates had elected to split it three ways. Instead, you unintentionally overeat and go home feeling sluggish and uncomfortably full. 

In this example, it was nearly impossible to figure out a reasonable serving size thanks to your large portion. But how can you determine how much to eat without breaking out a food scale and measuring cups in the restaurant? 

The Difference Between Serving Size and Portion Size

Ideally, we would all be able to tell how much to eat by the cues our stomach gives us. Eat when you’re hungry, stop when you’re full. Unfortunately, it can be difficult to pay attention to these cues if your body is used to overeating. Eating in a social situation can be an even bigger challenge because you’re focused on enjoying your company and may not realize you’ve eaten too much until it’s too late. 

That’s where serving size and portion size come into play. So, what’s the difference? 

• A portion is how much food you eat at one time. In the case of the overloaded pasta dish, the portion the restaurant served you was so big the portion size you ate also became distorted. 
• A serving size, on the other hand, is the recommended amount of a food to eat, based on the Nutrition Facts label or in consumer education materials. If you’re trying to lose weight or curb your overeating habits, sticking to serving size is one of the best ways to do it. 

Of course, that’s often much easier said than done—especially if you don’t have the right tools to measure out exact servings every time you want something to eat. 

Luckily, with a little practice and education, determining the right serving size can soon become second nature. Plus, as you retrain your body to only want the necessary amount of food, you’ll be able to better understand your stomach cues and eat more intuitively. 

3 Tips for Sticking to Portion Size

1. Visualize It

Comparing serving size to a well-known object can be an easy way to eyeball the proper amount without having to measure. For instance, a serving size of meat (three ounces) is about the size of a deck of cards, a serving size of pasta (one cup) is about the size of a baseball and a serving size of cheese (one and a half ounces) is about the size of four stacked playing dice. 

2. Put It On a Plate

Serving size is harder to designate if you’re eating from a package. Instead, eat your food off of a plate so you can be aware of exactly how much you’re eating at one time. 

3. Avoid Distraction

One of the main reasons so many of us have lost touch with our natural stomach cues is our habit of eating while doing something else—like watching television. Instead, try to eliminate distractions and focus on how your body feels as you eat. That way, you’ll notice when you begin to feel full and avoid overeating. 

For more serving size tips, take the American Heart Association’s serving size quiz.

Download our free guide to healthy eating in just five steps here.