[AngusH]

We could look at historical laws that did exactly this.

Set standard sizes and only allow sales in those size on penalty of prosecution.

For an example from the uk, until a few years ago bread could only be sold in 400g or multiples thereof.

You couldn't sell most kinds of bread except in standard sizes, so shrinkflation couldn't occur.

There were some exceptions obviously and you could have bigger multiples (like the mythical 1600g loaf)

https://www.fob.uk.com/about-the-bread-industry/how-bread-is...

The standard approaches on how do this date back centuries.

Milk gets sold in standard pints (err... 568ml), beer in pints, flour in 1kg bags, etc.

I actually think these restrictions are a good thing, with permitted exceptions possible for some specific things