Back in July 2018, Dr Annette Bosworth MD, posted a video on YouTube, which is based on advice which she gives to her patients, when they start a ketogenic diet.
Dr Boz suggests making use of frozen pre-prepared vegetables at first plus fresh veg. Going through your herbs and spices, to throw away the out of date stuff (good time to throw out any seasonings or spice mixes with added sugar).She says that lemon juice and lime juice are a good way to add flavour (if buying bottled, make sure there’s no sugar or sweeteners) . She gives a list of things which she regards as essential.
Dr Bosworth advises her patients to buy nuts eg pili nuts, macadamias and almonds. Olives perk up salads and dill pickles without sugar are good with cold meats. ( If you are in the UK, Morrisons sells Kuchnia Pickled Cucumbers which have no added sugar or additives, 1.35 for a 700g bag) )https://groceries.store.morrisons.com/products/105242997/details
Sour cream, heavy (double) cream, cream cheese and mayonnaise are suggested. (If you can’t find a mayo without added sugat, why not make your own ? Really easy with a stick blender).
Eggs are another essential. In Britain, it’s not necessary to keep eggs in the fridge, since they are reared more hygienically than in the USA.
Dr Bosworth advocates eating sardines, salmon and mackerel (all of these can be found in cans). She also talks about liverwurst and liver pate.
The saturated fats needed are lard, butter and coconut oil. Other healthy oils are avocado oil and olive oil.