All the festival food probably is gone on the 13th lunar day of the year. Most people just eat something simple on this day. Some people eat vegetarian foods to cleanse their digestive system.
This day is also the death anniversary of General Kuan Yu. Some Chinese will visit the temple of General Kuan to pray for safety and money luck.
Kuan Yu was a general in Three Kingdom period, (2211-263 AD), after late Han Dynasty. He killed a bad guy and disguised himself with a red face when young. He helped his friend and tried to recover Han Dynasty. People remembered his brave and skillful in fighting, righteousness, loyalty to friends, faith and act of justice. But he ended with a beheaded general. After his death, his spirit wouldn't die and his divine image appeared on the sky several times. People worship General Kuan Yu to repel evil spirit away.
Also, some Chinese treat General Kuan as a God of Wealth. This is because General Kuan won hundreds of battles and business people want to won the battle on the business deals.