Free Weight is the idea that an person has full control over how much they weigh. I will use the following definition and follow it with a refutation.
Free Weight: “The ability to have, of ones own accord, chosen to weigh otherwise than they did.
How to disprove ANY free weight argument in 2 easy steps
1. Ask the free weight believer to give an example of weight they consider to be freely gained.
2. Ask the free weight believer to say whether or not that weight gain was caused.
Congratulations; you’ve won!
If the free weight believer says the weight gain was caused, the causal regression makes free weight impossible.
If the free weight believer says the weight gain was uncaused, that would mean the weight gain was random. Random weight gain is not what we mean when we say a person chose to gain weight.
You can easily apply this two-step refutation to any, and all, free weight arguments.