It is clear that too many people have weight problems and that supermarkets are resposible for some of this problem. There are problems with the food they sell, and with the packaging, and with their attempts to encourage their customers to buy more.
One of the causes of weight gain is eating too much. One of the causes of eating too much is buying too much. So it seems highly reasonable to say to supermarkets that  they must encourage their customers to buy in the type of quantities they would have bought before supermarkets existed. The revolutionary government will ban all offers on food that offer a lower price for buying more, and all mulipacks. Butter and substitutes, will be sold in 250g packs, all butter substitutes will be subject to VAT. Cheese will be sold at a counter, and cut to the customers request. Bacon similarly by the slice. All vegetables and fruits will be sold loose, so that the customer can buy exactly the amount the wish. Crisps will be sold in 25g packets only, and of course the price per pack is the price, whether you buy one or 10. The same will apply to pringles or doritos. Dried fruit will be sold loose or in small packs. Soft drinks of all kinds will be sold in bottles of no more than 1 litre, and carry a returnable deposit.
Alcohilic drinks will be sold at a separate counter, like cigarettes are, and must be paid for by cash or debit card, seperately from other items.