Hazrat Faqeehul Ummah Mufti Mahmoodul Hasan Gangohi (May Allah shower his mercy on him) said:

There is a difference between اسراف and تبذير. Where it is permissible to spend, it is اسراف to spend more that needed. Allah says:

وَكُلُوا وَاشْرَبُوا وَلَا تُسْرِفُوا

Eat and drink: But do not be extravagant. {Al-A’raaf:31}

Eating and drinking is part of ones need. It is permissible to spend on it. (However) to spend too much is called اسراف.

Where it is not permissible to spend money in the first place, to spend there is تبذير. Allah says:

إِنَّ الْمُبَذِّرِينَ كَانُوا إِخْوَانَ الشَّيَاطِينِ

Verily the squanderers are ever the brothers of the Satans. {Al-Isra:27}

By spending on impermissible things one becomes an assistant of Satan.

Fatawa Mahmoodiyah Vol.30 Pg.406