I watch it. I agree with most of what you said until the second to last sentence. They DO have to think and make choices. The mind is the most important thing when it comes to losing weight and exercising. It’s 90% mental. If they don’t work to their fullest potential, the won’t lose the weight. If they don’t eat right, it will work against them. They need to make the choice every morning to get up and work at least 6 hours per day. To some extent they are told what to do and how to get there, but THEY are the ones that have to do it. It’s all about choices.

It is also my understanding that they have to cook their own food.

I only watch the very end to see how they did after the show. It gives me modivation to get rid of my weight when I see what they accomplished after they went home

…and personal trainers lead them through a strenuous exercise routine with them daily.
That part of your scentence just doesn’t sound right to me. (If you are writing an article.)
the “lead them through” and “with them daily” just don’t seem to go together in your scentence.
I know you didn’t ask for a writing critique, but I couldn’t help myself.

No. It holds no interest for me.

Yes, their only task is to lose weight and they are secluded on a ranch. But you seem to be saying that they are like puppets, and that trainers and cooks pull all the strings. They aren’t just lead through a work out – they are trained to use the equipment and are taught about body composition. I don’t know who does all the cooking – I’m sure they have some sort of staff – but you do see them doing at least some of their own cooking on the show. They learn about food choices and calorie counts. They have challenges every week, and many of them are based on what they’ve learned about food. While they all want to stay at the ranch as long as possible, they know they’ll all be going home at some point, so they’re preparing for it. The show doesn’t end at the ranch. They have to go home and prove that they can do it on their own.