I can't see how you are spending that! Half the food listed is what I call ' party food' ie fish fingers/ choc moose etc
We are family of 4 also ( although younger children). We buy all our meat in a London organic butcher ( so not that cheap), and the rest from Waitrose, and organic where possible. We spend about £100 a week.
I can't see how you still spend £100 a week when no meat and in lidl.
One thing here is no one snacks, do you spend a large amount on snack food?
Typical meals here:
Breakfast : porridge with fruits and nuts, or poached eggs/ tomatoes/ mushrooms
Lunch : homemade soup and roll, large salads with chicken/ avocado/ goats cheese, baked potatoes, or bread/ cheeses/ pates/ salads
Dinner : typically a meat or fish with veg ie steak with creamed leeks, broccoli, and green beans. Or something like lasagne/ risotto/ curry etc
Children have Greek yogurt and fruit if they want a desert
It's about £35 in butchers and £65 in Waitrose/ ocado