Are you free to buy a yacht? I would hazard the vast majority of people would say no, of course not. They can't afford it. Technically, anyone in this country is free to buy a yacht, but is obviously constrained by economics and geography from doing so. So while you're technically "free" to do it, the ability is severely constrained. But that's not a big deal. A yacht might be nice, but no one would argue that every person should have one. We don't have charity yacht banks, or holiday yacht drives to help those who can't buy a yacht get a yacht.
Are you free to control the food you eat? I would hazard the vast majority of people would say yes, of course. And I say you'd be wrong. I believe you are every bit as constrained from controlling the food you eat as you are from being able to own and maintain a high-priced luxury item like a yacht. Because when I say control, I mean every meal of every day to ensure you are eating what is really food and not just consuming calories thinking you are eating food. You are constrained economically and geographically from being in control of what you eat. And very much unlike a yacht, everyone would argue that everyone (including—even especially—Keira Knightly) needs food.
If you have ever tried to truly control what you eat, you will know what I mean by economic and geographic constraints. Eating real food is frighteningly expensive in both time and money. It takes an enormous amount of time to research, fact check, and investigate what is in food and how it's produced and then a significant amount of money to actually purchase food that isn't full of preservatives, chemicals, ridiculous amounts of sodium, antibiotics, hormones. Then there's figuring out what is fed to the food. That's even before you add other societal factors into your food decisions including cruelty-free, environmentally sustainable, locally grown, or anything involving human rights in the production process. That's a whole other chunk of time in research and a whole other surcharge on actually controlling your food.
By the way, this is just to attain the same food standards as your grandparents ate as a matter of course.
The only way to truly control what you eat is to either 1) make it yourself after having done all the aforementioned research or 2) have the money to hire someone to make it according to your dictates. For the first, you have to have the time to actually prepare the food (including some of the base ingredients like mayonnaise or sour cream or salad dressing). And having that kind of time means having the kind of money that you don't have to be working as much to earn it. For the second, your choices are an independent restaurant where you know what ingredients the chef uses and where the restaurant sources its food (and that's going to be a very high end restaurant so you better have the money), a personal cook that follows your directions on sourcing and preparation, or a company that produces foods according to your directions. Good luck with that last one for your every day meals. And of course, all the money to afford the higher prices those services cost.
So only if you have the time and the money to do all of that are you truly able to control the food you eat.
Depending on where you live, you may very well be geographically constrained in having any control over what you eat. Oh you may have the choice between one pre-packaged edible food-like substance and another edible food-like substance, but that's not controlling your food choices. Or you might have a choice between vegetables, but without spending the time and money to travel to where you have real choices, your choice is most likely between the pesticides used. I don't know about you, but choosing between poisons is not what I consider control over my food.
Which brings me to the latest kerfluffle and the outrage over the guidelines proposed in New York City about the amount of sodium in packages and certain restaurant foods. OMG the HORROR!! They're going to be restricting my table salt (no) or top chefs from practicing their craft (not).
There is probably no place in the first or second world where economics and geography more constrain food choices than in New York City. Where you have to have more time and money to eat real food rather than edible food-like substances. OMG the HORROR that you will actually be able to determine—when you have to eat an edible food-like substance rather than real food because you're not a member of the leisurely wealthy—at least what the upper limits of one ingredient are. Founding Fathers who never had to worry about corporations poisoning them every time they took a bite of food are surely turning over in their graves.
The majority of the world and a majority of America is as free to control their food as they are to buy a yacht. Technically free, but completely unable.