This prophecy has several different situations in which the events of it will play out.  The first of these speaks of a time that, due to lots of scares caused by tons and tons of food recalls, disease or poisoning of the food, nobody will know what's safe to eat and what's not, and thus they will starve because they will be too afraid to eat the food that's available to them because they're afraid to be poisoned or infected.  So it won't be an actual shortage of food, as there will be plenty of it out there to be had.  It's just that nobody will want to buy it for fear of it being poisoned.

The second scenario, that may happen side by side with the first, or possibly back to back, is a situation where artificial food shortages occur that are not actual shortages, but rather issues like kinks in the supply line, shutdowns of plants, withholding of food, etc.  IE, there's still plenty of food out there, but it's being prevented from reaching people, thus creating artificial shortages, and false famines in the midst of plenty.  Eventually there will be a real famine where there actually won't be enough food to be had.  However, this particular prophecy speaks of the famines that will be entirely fake, artificial, and manufactured.