Hawzah News Agency – Imam al-Sadiq peace be upon him says:

لَيْسَ شَيْ‏ءٌ أضَرَّ على قلب المُؤْمِنِ مِنْ كَثْرَةِ الأكْلِ، وَهِيَ مُورِثَةٌ لِشَيْئَيْنِ: قَسْوَةِ القَلْبِ، وَهَيَجَانِ الشَّهْوَةِ.

'Nothing is more harmful to the heart of a believer than excess food. It leaves him with two traits: hard-heartedness and burning lust.'

Source: Misbah al-Shariah, p. 239