Is it true that eating baby food is helpful for bodybuilding?

No: There are no hidden secrets for success in bodybuilding. It takes hard work and consistent effort supported by an appropriate diet and adequate rest. An appropriate diet includes enough calories and protein to support new muscle development with the correct nutrients. This is best achieved with whole foods. Sorry. No shortcut there.

Bodybuilding babies?: Most "baby food" is just puréed adult food. Like babies and other adults, body builders need to eat a healthy balanced diet. Body builders should probably eat a higher proportion of lean meats. There is no need or benefit to eating this puréed unless that is your personal preference.