In the United States, the amount of GMO foods that are eaten is not known, but it is reasonable to assume that it is a very high percentage. For example:
The vast majority of GMOs are developed to be resistant to herbicides or to produce a substance in the plant itself that kills insects when eaten. GMO foods, as far as is known, last no longer than non GMO foods.
Some GMO crops are genetically engineered to produce a substance that kills insects when they is eaten by them. It is for that reason that some GMO crops are classified as pesticides by the EPA.
GMO corn and soy are no more productive than non-GMO corn and soy.
The effects of GMO food is not yet known. Though some say there are no harmful effects, others question that and claim there is anecdotal evidence that GMO foods are harmful to health.
The percentage of GMO foods on a table depends on what types of foods that are bought. If a lot of processd foods are used, it is likely that almost all have GMO ingredients. If a lot of fruits and vegetables, 100% organic, and foods with the "Non GMO Project" label are used, very few or no GMOs are being eaten.
Most people who don't want GMO food are not convinced it is totally safe for human consumption.
GMO ingredients are any foods or food ingredients that have been genetically modified in a lab.
At this point in time, it appears they do, although they of course don't advertise that they do.
GMO foods last about the same amount of time as non-GMo foods.
Yes, 70% or more of the processed foods sold in the United States contain GMO ingredients.
The number of people who do not want GMO food is not known. What is known is that a large percentage of people want GMO foods in the United States to be labeled like they are in England. They want to be able to make an informed choice about the food they eat, and many do not want to eat GMO foods at all, but labeling GMO foods has come against opposition from biotech and food companies.
The cost of GMO foods purchased in grocery stores is not known because what foods are GMO are which are not are not labeled. There are also many factors that affect food prices, so it is difficult to know how GMO ingredients in foods affects price.