Why is genetically modified food used?
Lots of reasons - mainly to feed us all.
Genetically modified food goes under the branch of GMOs - genetically modified organisms.
There are many benefits, yet potential dangers from consuming GMOs - these reasons are why we use them. I will go over the main ones.
If you go into your supermarket and purchase food from the fresh fruits section, 90%+ of the food has been genetically modified. This is because human population is growing and we need more food to feed all of us.
Thus, a method to modify the DNA of the food allows for larger fruit, fast reproduction and more nutritional benefits. An example would include corn:
As for downfalls, because we are altering the DNA to be what we want, during reproduction, there is little diversity. As a result, if a disease were to erupt and invade the (mono)crop economy, all the foods will be susceptible to such dangers.
In addition, pesticides can be found in the foods. Scientists are also not sure if eating so much GMOs will cause any negative impacts.
However, these positives far outweigh the negatives (opinion). Personally, when I go shopping, if a food product says "No GMOs", I don't buy it.
Hope this helps :)