How are genetically modified foods produced?
Genetically modified foods are all produced from genetically modified organisms (GMOs) by definition.
Pretty much ANY food eaten in the 21st century is genetically modified from whatever form it had centuries before.
The slow process uses cross-breeding of plants and animals in an attempt to enhance or combine desirable traits (size, disease/pest resistance, water needs) or reduce undesirable traits (poor yields, easily damaged, disease-prone).
The fast process uses manipulation of genetic material directly to add/subtract such traits from the defining genomes of the plant or animal.
In all cases there are possibilities of undesirable traits becoming too dominant or ecosphere disruption by hardier versions. However, those potential negative outcomes have no bearing on the individual food value of a crop. “GMO”s have no direct negative impact on individual health or nutrition. Not getting enough to eat or indulging in an excessive amount of eating for long periods of time will be detrimental to your health in either case.