It got downvoted because it's an anecdote and an anecdote isn't a substitute for a study that covers eighteen million people. We know the odd person can do it, 1 in 1667 per year if you're very overweight. That doesn't mean that 1 is representative of the set. In fact we know it's not representative. Because we have data.

It's like interviewing Michael Phelps and he's like "just swim! I did it! Anyone can win a gold medal by swimming." No, they can't.

And the reality is average weight gain over the 5 years following weight loss is 80%. Everyone who participated in the Biggest Loser weighs almost as much as when they started and has a metabolism an average of 17% slower than would be expected for someone of their new body composition. [1]

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4989512/

I'll push back and say anecdotes need more downvotes because they're actively harmful to the discourse, and are a large part of how we got to this point of just abject unhelpful information being passed off as useful.

This is how we get all sorts of medical misinformation like "I ate some almond seeds and my cancer went away." We don't accept these kinds of anecdotes in direct opposition to medical evidence for any other disease, we shouldn't accept them here either.

It's survivorship bias -- where are the anecdotes from the people who did exactly what parent said and didn't lose weight? They're in the study. Will OP update if they regain weight?

You can look up any of OPs rules, they've all been studied, and they don't work for most people.

You know what works? GLP-1s.

What matters for your health isn't that you tried real hard, what matters is that you lost weight. Nothing wrong with losing weight via GLP-1s then going to the gym and trying real hard to get jacked.