Flamin hi, welcome. I agree with belinda above, the plan itself is largely self limiting if you avoid the main foods (so no bread, potato pasta, rice, (I also avoid grains, cereals etc) plus sugar, and I only really eat berries and have cut out all other fruit). Ideally you’d avoid anything with sugar as an ingredient, and hugely limit anything with sugars occurring naturally. Some low carbers say 50g or less as a benchmark; others will count ‘net carbs’ so will deduct grams of fibre from the carb total. But really, there is no harm in having some days low and some days a bit more... I tend to hit around 30-60g (and I don’t stick to 800 calories every day either and still do that).
Re; shakes- I make mine with
250ml almond milk -33 cals
50g raspberries/blueberries- 16 cals
10g maca powder- 29 cals
20g peanut butter or 50g avocado or 80g full fat yoghurt - around 120 cals
Handful spinach - 5 cals
so it comes to 200 cals approx. But again it’s not a meal replacement as such, but it is high fat/high protein/ sugar free. It keeps me going all morning. I’ve not found one that I can afford online that isn’t artificially sweetened, or chocolate/vanilla flavours added to them.
Aldi do a great range of powders such as maca, spirulina, wheatgrass etc in their ‘foodie market’ range if that’s your thing to add to shakes.