6 months after I started weight lifting, I met Nico. I saw him before at the gym, he was muscular & strong, imitated his workouts. Then one day I asked him if I could workout with him, he said, "sure join me know, I'm doing legs". So I joined. First leg press, then squats. Never had done squats before (it was in the smith machine back then btw), went up to 60kg or so, adductors ached, cold sweat, etc. Puked afterwards in the shower (I only told him that 2 years later

) Came back the next day to workout again, but my legs hurt for 4 days.
I was a student back then, and I ate shitty food. That day I ate french fries with that junk meat they serve, typical belgian junk food (tasty but unhealthy)
I throw it all out. Never did I eat that again before working out, teached me a lesson.
Now there are some freaks who indeed eat McDonalds and can workout with problems. Good for them. I know Dave Tate (power lifte), ate nothing but junk food all day, and still squatting 800lbs. So if it works continue.
However, I believe strength training is more than just lifting weight. Strength training is improving your health too.
"A healthy mind in a healthy body" juvenal. Junk food is unhealthy, if you care about your health you need to eat veggies/fruits/etc. Clean food will prevent many other problems in the long run (cancer, allergies, liver health, etc)