It is said that "and army runs on its stomach". This is true of slaves as well. Feed somebody and they will be indebted to you. You have covered one of their basic needs and with the time they don't spend pursuing food, you can guilt them into doing labor for or at least supporting you. (This happens in a microcosm at work.)
So much labor is involved in growing, harvesting, cooking, and bringing food to a table, that it is a core sources of systemic functionality (Thereason people work so well together.) that defines a reason humans made it to the top of the chain. What many people who both profess the wonders of global capitalism and then complain about the influx of illegal immigrants into this country don't seem to grasp is the connection between the two in Central and South America. As the US has dumped cheap food on these communities in those areas, a few thing happened. First, the food is high caloric food that expands the physical and psychological "need" for more and more. As the documentary "Food Wars" put it, We are predisposed for gorging ourselves with calories when they are available in preparation for "the winter" but we live in a world where "winter never comes". That feeling is never turned off. However, when once a village or even a family needed a large percentage of their population dedicated to just doing one of the tasks associated with feeding, now a small crew can feed thousands (or billion and billions served) of people. Add to that a reality that the food comes from far far away where much of it is not done by the community, and you have essentially eliminated the functional need for more than 3/4ths the community/ family/ country. (This is the passive aggressive nature of capitalism.)
So what do you do when so many people no longer have lost their function their historic role in society? Send them to work in your dangerous factories fro low wages. Break up their families by making it so both mother and father have to work to make ends meet. A place where the kids will not see their parents hard work and only see the meager fruits of their labor. Expose them to the dangers of the influence of the violent drug cartels. Drive the very value of the producers down and then call them lazy, worthless, and beggars when they can not establish a respectful living and lifestyle.
A long time ago, when I had more "conservative" leanings, thinking it to be funny, I used to say, "if you want to take over a country, don't send troops, send McDonald's and Walmarts. In no time they will depend on your hand to feed them." I still "say" it, I just don't think it is funny anymore.