One of the ways people try to keep in shape is to keep track of what they eat.
However, not everyone wants to sit down and journal every food, topping and drink they throw back.
Two new devices introduced at this year's CES tech show in Las Vegas use your breath to determine what is lacking in your diet.
FoodMarble and Lumen have come up with devices that users blow into and information is transmitted to a smartphone app that will let you know how many calories you're burning and how your body is digesting food.
Lumen's founder Dror Cedar says the app tells you what your body is burning and suggests different recipes geared to each user's information.
"You don't need to guess how much sugar was in that Kung Pao chicken or how many calories you did on that run."
FoodMarble's founder Lisa Ruttledge says their device uses hydrogen levels to determine the effectiveness of digestion.
"That's happening because there's fermentation happening in your gut and some hydrogen created in that process is exhaled."