Muhammad Ibn Abdullah (SAW), the Messenger of Allah (SWT) said:
"He who has taken food and says at the end:
الحمد لله الذى أطعمنى هذا ورزقنيه من غير حول مني ولا قوة
Al-hamdu lillahi-lladhi at 'amani hadha, wa razaqanihi min ghairi haulin minni wa la quwwatin
All praise is due to Allah Who has given me food to eat and provided it without any endeavour on my part or any power
all his past sins will be forgiven." [At-Tirmidhi]
This Hadith tells us that if we praise Allah with these words after taking a meal, all our minor sins committed in the past will be forgiven by Him.