Fighting Their Fraud Act of 2023 This bill increases the criminal penalty for fraudulent activity related to child nutrition programs (e.g., the National School Lunch Program and the Summer Food Service Program). Specifically, the bill increases the maximum fine from $25,000 to $50,000 for embezzling, willfully misapplying, stealing, or obtaining by fraud any child nutrition program grant or assistance funds, assets, or property (that is valued at $100 or more); or knowingly receiving, concealing, or retaining such funds, assets, or property for personal use or gain.