This is the fourth story in a nine-part series on the emerging wave of new-generation technology that monitors our health and wellness.
Are you planning to eat that? New wearable and smartphone technology is coming that can tell you whether it's a good idea.
Some of the technology is already here. Looking for a sensor-filled cup that can tell the difference between Coke and Pepsi? A jar that sends nutrition information up to the computer cloud and down to your wrist?
Speculation is that the new Apple Watch, to be shipped in April, will make it easier to monitor food and health data. Some experts also say that the day is not far off when you'll be able to wear a device that analyzes the nutrients in your bloodstream and will tell you, for example, whether you ought to eat a banana, and where the nearest fruit stand is located.
"I want that!" says Kris Gross, a Canadian pro-mountain bike racer and instructor who now lives in Southern California. "Potassium levels are a big concern for cyclists. It would be great if there was something that could alert you when it's getting low."
Tech developers warn, though, that there are limitations to wearable tech that connects to your food. The devices on the market now, or just about to arrive, are not quite at the banana-detecting level yet.
Also, other prospective customers appear to be wary.
"I don't use any of this stuff but I probably should," says Vaune Davis, a TV news producer from Toronto who won the 2014 endurance cycling World Cup. "When I'm riding, I'm concentrating on other metrics, so I don't have the brain space for another gadget."
Nutrition experts caution that no matter how advanced the technology telling you about your food becomes, it's no substitute for actually eating and drinking properly.
"Wearable sensors hold a lot of promise for getting objective information about people's eating behaviours," says Andrew Brown, a professor at the University of Alabama at Birmingham and scientist with the school's Nutrition and Obesity Research Center and the Office of Energetics.
"However, we need to be careful with how far we collectively extrapolate the data. I like to consider what the device is designed to tell the user. I think of it in four broad classes: eating behaviours, what types of foods people are eating, what amounts and nutrient contents people are consuming and an individual's nutrient status."
There are wearable and portable devices that gather and provide some of this data, but not all. For example, there is wearable tech such as the OMsignal shirt, which monitors workouts and sends data to smartphone apps on workout intensity, heart and breathing rates and how many calories are burned.
It's not cheap – $250 (U.S.) for a shirt, data module and USB cable. It goes only so far; it is water resistant but not something you swim in, and it tracks the wearer's output but not the composition of the food ingested.
Food and liquid input can be tracked with new devices such as the Neo SmartJar, being developed by Toronto-based SKE Labs Inc. and launched as a prototype last January. The company is hoping to bring its product, which looks like a water bottle for yoga class, to market in October.
"It's a jar that has sensors built into the base," says Madhuri Eunni, the company's founder and chief executive officer.
"You put what you want to eat into the jar and enter the ingredients online one time, through our app. The data goes to our cloud server database," she explains.
"Based on your own consumption, the app can tell you the calories, protein, fat and other ingredients you're consuming. Instead of glancing at the ingredients on the back of a package, the app can give you context. You can track data such as your weekly consumption of sodium, for example."
Eunni concedes that a jar, although almost an appendage for many, is not quite wearable. Also, users can't exactly put a steak or a grilled cheese sandwich into a SmartJar for analysis.
Another product called Vessyl, from California, is a cup that is paired with an app. The app will provide readouts showing whether what you're drinking will either help or hurt your hydration (some liquids such as coffee make you more thirsty). The cup itself will give you information on caffeine and sugar levels – which are different in different types of coffee and soft drinks.
"It's really hard to figure out who the target market is going to be for that level of detail," says Olivia Affuso, a professor in the University of Alabama at Birmingham's department of epidemiology.
"I'm actually a fan of wearable technology. But the information has to be accurate," she says.
Affuso also worries whether people are overdoing it when it comes to accessing data; she worries whether people are spending so much time on mobile devices that it interrupts their sleep patterns. "That can lead to obesity," she says.