Understanding Portion Sizes

One of the most important decisions we make about food is how much to eat. Many people struggle with portion sizes. Most of the time we eat portions that are too large and this contributes to weight gain. Use this guide for making healthy choices when it comes to portion control.

What’s the difference between a serving size and a portion size?

A serving size is a reference amount of food as defined by Health Canada. The Food Guide lists amounts of foods that are equal to one serving. 

Food manufacturers also decide what makes up one serving for their products, and it’s not always the same as the Food Guide. You will see this amount listed on the Nutrition Facts Table on the package label.

A portion size is the amount of food that you actually put on your plate, that you plan to eat in one sitting.   Depending on the food, your portion size may be one or more servings according to the Food Guide. For instance, if you eat a whole apple as one portion, that equals one serving of vegetables and fruit. However, if you eat a sandwich with two pieces of bread (one portion), you’re eating two servings of grain products since each slice of bread is one serving according to the Food Guide.

How well do you know the difference between a serving size and a portion size? Take this quiz to find out.

Why is portion size important for healthy eating?

Ever heard of portion distortion? This is when over-sized portions of food start to look normal to you.   The result is that people will eat whatever is on their plate without thinking about the number of serving sizes that are actually in front of them. Portion sizes that once would have been considered far too big to eat in one sitting, are now seen as normal. From store-bought muffins, to soft drinks and to pasta entrées at restaurants, portion sizes have increased over the last 20 years. Bigger portions mean more calories, and the result is bigger waistlines. 

Tips to watch your portion sizes:

• Find out how much you need each day using Canada’s Food Guide and try to eat about that amount food on most days.
• Try to get good at “eyeballing” food portions, and knowing how much is in a serving size. To help you practice, use measuring cups and spoons or a food scale.
• Find out if your portion sizes are on track. Try EATracker, from Dietitians of Canada.
• Put food on a plate rather than eating out of the container – we often eat more if we can’t judge the portion size.
• Studies have shown that we will eat more when using bigger serving dishes. Use smaller, salad-size plates (and other smaller serving dishes) rather than large dinner plates. You'll likely eat less! 
• Pay attention to the label on packaged foods. All nutrition information is related to the amount of food listed in the Nutrition Facts table, which may be less than your portion. Always adjust nutrition information to the portion size that you are eating.

Helpful hints for measuring portions:

When you don’t have measuring cups or scales available, use your hands or common items to figure out reasonable portion sizes. See the chart below.

Do you have more questions about portion sizes and weight management? Call EatRight Ontario at 1-877-510-5102 to speak for free with a Registered Dietitian or send an email.