How to Avoid Portion Distortion

You’re all about healthy eating, taking care to prep and cook nutritious meals to fuel your body and support weight loss, and yet the scales simply won’t budge… Have you considered portion control? Portion distortion could be the thing holding you back from success on your weight loss journey!

Portion control is a hot topic in health right now. Even McDonald’s in the US. has done away with supersized meals in response to changing customer demands.

And it’s not just a food industry or weight control trend. Several recent studies examining the relationship between portion size and what you eat have provided helpful insights for anyone trying to downsize – on dinner or body dimensions.

What you see is what you eat

When it comes to portion control, your eyes are the boss. In fact, according to several recent studies, what your eyes see on the plate determines to a significant extent how much you eat.

For example, if there are 20 cashews in a bowl, you might take six or seven (making up 110 calories). However, if there are 50 cashews in a bowl, you’re more likely to take a handful of 15 (equating to 240 calories). In both cases, your eyes will tell your stomach and mind that you’ve had a moderate portion – but the “moderate portion” from the larger bowl contains 130 more calories… A significant difference!

This can make a big difference when it comes to weight control. A study involving university students showed that when the students served themselves snack food from two different-sized serving bowls, those who ate from a 4-litre bowl consumed 42% more food than those who ate from a 2-litre bowl.

When asked to take a “normal” serving size of snack food from two different-sized bowls, participants in a related study took 50% more from the larger bowl.

Portion control tip: Both of these studies reveal that the bigger the serving bowl, the more you tend to eat because you think it’s a “normal” amount. To overcome this portion distortion, try serving your food on smaller plates or weighing your food so you know exactly how much you’re eating. Don’t rely on your stomach to tell you when you’re full!

A good deal?

Large packaging sizes on supermarket shelves are still a major barrier when it comes to portion control.

Studies show that larger package sizes make people eat more. A team of scientists at the University of Illinois conducted over 50 experiments involving everything from spaghetti to popcorn to laundry detergent, and found that larger package sizes can cause people to consume up to 48% more of a product – whether it’s food or not!

So while it might seem like you’re getting a good deal when you buy a large bag of pretzels for only 40 cents more than the regular size costs – you’re costing yourself more in terms of calories. You also don’t save much when it comes to cost. Research shows that you simply use more or waste more when you upsize. From this standpoint, a larger package can often be more costly.

Portion control tip: Aside from the obvious advice to buy smaller packages, try purchasing bulk-size products and then splitting them up into reasonable portion sizes in separate containers as soon as you get home. This way you really do get a good deal, without “spending” unnecessary calories.

Just because you don’t like it doesn’t mean you’ll eat less

If you don’t like something, you won’t eat much of it, right? Think again!

In a study involving popcorn and moviegoers, scientists demonstrated that even those who didn’t like popcorn ate more of it when given a larger portion. Moviegoers in the study who didn’t like popcorn still ate 61% more when they were randomly given a large container of it.

If you find yourself mindlessly reaching for snacks or treats, in social settings or at home, of foods you don’t even particularly like, think about where you could better “spend” those calories.

Portion control tip: Don’t be fooled! Portion size influences the amount you eat no matter how much you like or dislike the food itself. A good rule of thumb if you’re not partial to a particular high-calorie food is not to eat it at all. Save your calories for foods you actually enjoy!

Using portion distortion to your advantage

Usually, serving smaller portions is the goal of portion control, but sometimes you can turn that logic around. If you consider that the bigger the portion, the more you eat, then eating those greens might not be such a challenge after all!

If you struggle to eat a healthy food that you know is good for you, such as broccoli, try putting more of that food on your plate. Fill your bowl to the brim with brown rice or bran cereal. Load your lunchbox with pieces of fruit. Put an entire jug of water on your desk at work – not just a glass. Although you’re unlikely to consume the whole lot, you will eat and drink more than you would if you used smaller portions.

Portion control tip: Increasing the portion size of healthy, low-calorie foods you don’t particularly like can help you eat more of them. Serve yourself lots more than you want to eat, and you’ll probably eat close to a healthy portion size. If you’re going to leave half your carrots behind – make it a big half!


This article was compiled in consultation with Calorie King experts and in reference to the following sources:

Brain Wansink and Matthew M. Cheney, “Super Bowls: Serving Bowl Size and Food Consumption,” JAMA 293:14 (April 13, 2005), 1727-1728

Brian Wansink, J North and J.E. Painter, ‘Why visual cues of portion size may influence intake’, Obesity Research, forthcoming

Brian Wansink and S. Park, ‘At the Movies: How External Cues and Perceived Taste Impact Consumption Volume’, 200, Volume 12:1, 69-74

Brian Wansink, ‘Can Package Size Accelerate Usage Volume?’ Journal of Marketing, Volume 60:3 (July 1995), 1-14

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