A Device That Counts Calories for You

GE researchers are developing a system that calculates the exact calories in food using microwaves

GE Calorie Counter
A mock-up of what GE's calorie-counting device might look like. General Electric

If you ask any doctor how to lose weight, he or she will feed you exactly the line you’d expect: “Diet and exercise.” Absent a personal trainer and a nutritionist, most of us fend for ourselves when it comes to setting a plan—and sticking to it.

Thankfully, when it comes to exercise, the recent crop of fitness and activity monitors have stepped in to keep tabs on just how much we move—some even go as far as customizing workout routines based on our current state. But, as the good doctor would agree, that’s only half the picture.

While the apps that work with those fitness trackers—not to mention the separate glut of dieting apps—let users keep a tally of their daily food intake, that process is far more cumbersome than tracking steps. Users must enter each snack, drink, entrée and side dish by hand. It’s imprecise, inaccurate and just plain annoying. (Although anything’s better than setting things on fire, right?)

Researchers have long been trying to develop tools that will do all the calorie counting for you, and a team at GE Global Research has now come closer than any other before them. Their system uses microwaves to accurately estimate the calories on a dinner plate.

According to Matt Webster, senior scientist specializing in imaging and biomedical technologies at GE’s lab, the primary issue with existing calorie-counting apps is that the amount of calories in a piece of food—say a tuna sandwich or a salad—can vary greatly from plate to plate and from preparation to preparation.

“How well does that burger you ate match with the burger you selected using an app? Are the serving sizes the same? Do any of the app database entries accurately reflect what you cook at home?” he wrote in a blog post about the project, which he led.

So Webster’s challenge was to develop a system of sensors that could accurately estimate the caloric content of the food in front of it. Lucky for him, he discovered early on in the project that you can figure out the amount of calories in a piece of food if you know its weight, fat content and water content.

Sugars, carbohydrates and proteins also play a part, so the algorithm Webster developed accounts for those variables in its calculations—the “secret sauce,” as he calls it.

The system itself, which still exists only as a crude prototype, gets the information it needs by bouncing microwaves through the food. “Water and fat interact with microwaves very differently,” Webster told GE Reports. The microwave signature that the sensors detect helps determine just how much water and fat are present.

Together with researchers at the Baylor University Department of Electrical and Computer Engineering, Webster and his team are testing their system on simple solutions of water, oil and sugar. In a video demonstration (above), the system correctly tabulated the caloric content of one such mix, and researchers say it’s always accurate within 5 to 10 percent of the actual value.

Compared to other food-scanning devices, GE’s system rings feasible. Earlier this year, for example, a device called TellSpec got a lot of attention (and a ton of crowd-funding cash), purporting itself to be a handheld tool that calorie counts using a radio spectrometer, a technique typically used for studying cosmic radio emissions. Since its Indiegogo campaign, however, physicists have severely questioned the validity of the technology, and TellSpec has scaled back many of its claims. And just last month, Vessly, a California startup, began showing off a cup that tabulates the calories present in any beverage inside it—the means by which it does this are as yet undisclosed.

Webster's dream product is a sort of bonnet that users can rest on their dinner plates. At the press of a button, microwaves would scan the food, sensors would detect the fat and water content, and the resulting calorie count would sync with a smartphone.

Eventually, the system could also pair with an activity tracker and digital scale, creating a complete diet-and-exercise ecosystem.