Bodybuilders are at their weakest after they loose all that fat for competition. And they dehydrate themselves as a bonus. They sometimes even faint due to that.
It is not healthy what they do around competition. It is not workable advice for general population either, because acting like that all the time is pretty much definition of eating disorder.
Yes they take it to the extreme, the unhealthy extreme. Competition day is not a maintainable look and is your body at its weakest, it’s a one day event only. No normal person needs to or aspire to be a competition day bodybuilder unless they want to win a bodybuilding competition, guessing most don’t and most people couldn’t.
It’s definitely not healthy to go to that extreme but I do think there is a lot in following the process and general diet to loose fat then maintain it at a reasonable level.
If you take the competition extreme side out of it the bodybuilding diet is pretty good. Complex carbs, lean meats, lots of greens, nuts and seeds for fats. Fitness model might be a better example as they don’t push it to the extremes are lean but can maintain the shape quiet healthily.
It is not healthy what they do around competition. It is not workable advice for general population either, because acting like that all the time is pretty much definition of eating disorder.