No — and this is a common worry that stops people from coming forward. Saved food and packaging are helpful, especially for identifying a specific product and lot, but a food poisoning claim does not depend on them. Most people do not think to keep the food, and that alone does not end a claim.
Plenty of other evidence establishes the source. Your medical records and any lab confirmation identify the illness and the pathogen. Receipts or records show where you ate or shopped. The timing of your symptoms points to the likely meal. And any related outbreak investigation or product recall can tie your illness to a source directly.
So if you were seriously ill from food but kept nothing, it is still worth a review. We can look at the medical evidence, the timing, and any public-health or recall information to see what the source proof supports. Acting sooner helps preserve the freshest evidence, but it is rarely too late to ask.