Since this also keeps coming up...
In 2122, despite the reversal of many previously harmful environmental practices that had reversed global warming's effects, the climates of Earth experienced a minor shift similar to the mini-ice-age previously seen in Elizabethan times. The resultant slight clmate shift had the predictable effects of making the northern reaches of the United States colder, the southern states a bit drier, and subtley shifted the weather patterns of the globe. While this did not have the catastrophic effects it might have otherwise had if the polar ice caps had in fact melted, the climate shift was enough to throw the ecology of many food producing regions out of alignment.
New disesases and blights on crops flourished, as did diseases in livestock. The resultant effect on the bee and butterfly population eradicated many of the pollinating insects needed for fruit and vegetable growth. The result was a major decline in the globe's ability to produce food for its burgeoning population.
Cloning laws which previously outlawed all types of whole-body cloning were adjusted to allow for the cloning of the surviving livestock herds leading to the development of Gen-cattle, gen-chickens, gen-pigs, etc. Fundamentally the same as their natural counter-parts - and often healthier - the debate still rages as to whether gen-animals taste any different. Gen-herds are typically raised from a core herd of animals and are routinely checked for genetic anomalies and health problems.
Plants become a more controversial matter as even most people consider gen-animals to be equal or superior to natural animals. Plants, however, tended to alter taste via cloning due to the required growth suppliments added in. Many people insist that gen-vegetables and gen-fruit are by no means equal to their previous natural counterparts despite being nutritionally equal. However, since cloned plants are significantly hardier and survive colonial transport much better, there are many humans that have never tasted natural fruit or vegetables.
Potato blights were so extensive that for the next two hundred years, actual potatos were considered to be extinct until a small, unblemished crop was discovered growing wild in the woods of Idaho. Today, real potatos are so expensive as to be considered a luxury food item akin to caviar.
Tomatos still exist in natural form more frequently but are rare enough that most people buy the gen-versions.
Oranges and citrus seem to be very difficult to clone. While successful, these crops are the most noticably different from their natural counterparts.
The Ghost oubliettes make a good portion of their income by selling left-over crops and livestock. The calivada oubliette in particular has quite the stock of real vegetable gardens and real fruit orchards, as well as maintaining their own gen-livestock, subsisting off the growth of their labors, but using extra crops to raise income for the items the oubliette cannot grow itself. The calivada oubliette has not been successful in growing citrus plants.
Continuning in fine military tradition, the GAF uses a number of synthetically and clone created substitutes for food. Proten bars, calcium shakes, and vitamin paste are all standard fare for many of the outlieing ships and colonies. Whle some of the further out colonies also utilize these synthetic food substitutes as a matter of necessity, nearly everyone agrees that the taste of these products is undeniably wretched.