My dog ​​is very strong. My dog ​​eats nutritious food

While training may be a solution, there are ways to try to curb the behavior yourself.

If your dog is bored, try to find more time in your day to spend with them, and include fun, interactive toys
Always remove any dangerous objects from reach, in case they don't respond to training
Do not give your dog attention if they're behaving badly as it can reinforce the behavior
You can try spraying the items your dog typically tries to eat with a dog repellent spray, you'll need to be sure that it's non-toxic and intended for this purpose
If the cause for constant chewing or eating non-foods is due to stress or anxiety, your vet may recommend drug therapy if nothing else will work
If the behavior happens on walks, you may want to use a muzzle to restrict them from eating whatever they come across