The syrup, distilled from the Peruvian tuber yacon -- contains up to 50 percent fructooligosacharides, or FOS. FOS, classified as a prebiotic, is a non-caloric sweetener and also a fiber source. Inulin is an FOS and it is often added to processed foods to increase its fiber levels.
(And yes, it can be quite “combustible” to some people, so take it easy at first. The reason is that the FOS passes through the digestive system unmetabolized.) (in other words, go easy on the amount, use it sparingly, at first in your tea or cereal to sweeten or a dressing for a salad, because in large amounts it can make you poop)
Conversely, yacon leaf was once thought to be helpful in diabetes but in studies produced kidney damage in lab rats, so it should be avoided in teas and capsules form. Use only the Syrup form and sparingly, untill you get used to it, it has a slightly molassis flavour and consistency, so its great in baking.
It has a smoky, molasses-like flavor and you can use it like you would molasses, honey or maple syrup. You can drizzle it on oatmeal, use a spoonful in tea, add it to baked goods and any other opportunity where you need a touch of sweetness.
“FOS resist breakdown by enzymes in the human digestive system and reach the colon without being digested,” says Dr. Oz. “This means that yacon syrup is very low in calories (about 20 calories per tablespoon). FOS also acts as a soluble fiber, which increases stool bulk to help prevent and control constipation.”
Yacon syrup tastes sweet and has a consistency similar to molasses, and can be taken pure or as a sugar substitute.
