A dietitian reveals how to properly measure portion sizes using only your hands

Most of us struggle to measure how much food we’re actually consuming when we’re eating out.
How much of this pizza constitutes a single portion size? How much pasta is actually in this bowl of spaghetti?
But now, a dietitian from the University of Sydney posted a YouTube video explaining the key to properly measuring portion sizes when we’re on the go. The trick? Just use your hands.

“If you’re trying to watch your weight and you’re out to dinner, and you’re presented with a bowl of food, there’s no really good way to actually estimate how much you’re eating, unless you’re going to whip some scales out of our bag,” dietitian Alice Gibson said in the video.

Gibson and a team of researchers sought to find a more objective way for people to measure how much they’re eating when they’re out and about.

The researchers got people to measure the width of their food using their fingers. They then used the geometric volume formula that most of us learned in maths class when we were younger: volume = 1/2 (width times length times height).

To demonstrate, Gibson brought out a piece of lasagna (which, for measurement purposes, is shaped like a box), a glass of wine (which they say is shaped like a cylinder) and a piece of watermelon (obviously, a wedge).

Gibson found that the lasagna was seven fingers by five fingers by four fingers, or V=1/2(7x5x4).

The researchers believe that the method should be incorporated into smartphone applications sometime in the future, where people can put in their finger width measurements, as well as their height and weight, and then let hte phone handle the calculations.

“And then you’ve got a more accurate way to estimate the portion size,” Gibson said in the video.

NOW WATCH: Look what a world champion pastry chef can do with dessert

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.