Fat people used to suffer the same fate as these animals. They were told and then ordered to follow certain diets. Animals in zoos don't have much choice as to what they eat, with the possible exception of animals in particular areas in a few zoos. Animals don't have much of a choice as to where they can go. Often neither do fat people, who are mocked when they try to walk or exercise. Luckily fat people do have the option to persevere in their efforts. Animals mostly don't.
Caged animals have very few choices of mates. It is a bit easier for fat people, but sometimes not much. They are often banned from dating sites and clubs.
Caged animals are often artificially inseminated; breeding is highly managed. Fat people are often told that pregnancy will be very difficult for them or that they shouldn't think of having children (or even sex). Luckily there are a lot of people who disagree with the supposed experts. Fat people find happiness in relationships often when they relinquish the dating sites. And the opinions of supposed experts.
Like caged animals, fat people are happiest when left to choose their own habitats. Sometimes they even find places in which they are relaxed and fulfilled.
Now if that would only happen more often...