Carb is short for carbohydrate
, a component of food that is used mainly for energy in the body. Carb also means a gram of carbohydrate, so people will say "this apple has 17 carbs in it", or even more commonly will speak of foods having "lots of carbs" or "not many carbs".
Often, people on low-carb diets will use the term carb to mean the same as "effective carb" or "net carb" (generally total carb count minus the fiber). This is mainly because fiber, though a carbohydrate, is not used by the body for energy and does not raise blood sugar. See for more information, see:
Effective Carbohydrate Count
What is a Net Carb?
Understanding Carb Counts
Also Known As: carbs, carbohydrates, carbos
Sugary and starchy foods have lots of carbs, while a cup of lettuce has less than a carb (that is, less than one gram of carbohydrate).