These are gadgets that analyses the gases in people’s breath in an effort to reveal how they should improve their diet.
Lumen and FoodMarble are both pocket-sized devices that users blow into.
They each pair with a smartphone app that tells people how they are digesting food or burning calories.
But one expert said such technology is yet to be properly validated by scientists.
Lumen has designed an inhaler-shaped product that measures carbon dioxide levels in the users breath.
The firm says this provides a way of monitoring a persons metabolism – the chemical processes that, among other things, convert food into energy.
“You dont need to guess how much sugar was in that kung pao chicken or how many calories you did on that run,” explained founder Dror Cedar.
Instead, he told the BBC, the app simply explains whether the user is burning carbs or fat. It then suggests recipes that help burn fat and, over time, Lumen learns what diet is most appropriate for each user.
Lumen has been trialled by “hundreds” of users in the US, according to Mr Cedar.
However, studies measuring the effectiveness of the product have not yet been peer-reviewed.
It will go on sale for N109,200 ($299) this summer, though people who pre-order will pay N91,250 ($250).
The app might charge a subscription fee in the near future, but it will be free for everyone during its first year.
Conversely, FoodMarble measures hydrogen levels in an attempt to make deductions about a persons digestive health It was released in December. Nearly one million pre-ordered devices have already been shipped, the firm has said.
Founder Lisa Ruttledge told the BBC that hydrogen in the breath can be a sign that someone is having trouble digesting a recent meal.
“That’s happening because there’s fermentation happening in your gut and some hydrogen created in that process is exhaled.”
The idea is to help people who experience bloating, abdominal pain and other gastrointestinal symptoms. Through revealing foods that result in hydrogen production, FoodMarble could help them tailor healthier diets.
However, although such tests are sometimes used by doctors and dieticians, some question whether they are accurate.