Giant mealworms?

I just read online to avoid these as they are treated with a growth hormone to prevent them from pupating resulting in sterile beetles. Is this true? And if so does it harm the geckos?

It's best to avoid using giant mealworms yes, they are indeed treated with hormones to stop their pupating. If you need something larger than mealworms, go with superworms, or more healthy feeders like dubia roaches.

JESUS! I've been feeding my babies this crap!

It is debatable that dubia roaches are more healthy than supers for leos as no one has really established exactly what the specific nutritional needs are for leos regarding levels of protein fats and fiber required for optimum health. Everyone has an opinion on what feeder is best for leos but what is really best is an assortment of feeders, rather than just one type of feeder.

Very true, variety is key. I can totally agree with that.

Now comparing dubia roaches to superworms specifically, the striking thing about superworms is their high fat content & low protein values. Their Ca/P ratio is also pretty bad, amongst the worst actually. Although supplements & variety feeders can take care of those issues no problem.

Dubia roaches on the other hand, are low in fat, but can be too high in protein depending on how you gutload them. While too much protein can be bad, too much fat can be worse.

I think about the only thing most people can agree on is that low fat diets are better for geckos. But giving your geckos a good variety plus good controlled supplements are probably the best anybody can do for their leopard geckos.