It entirely depends on their diet.
2 adults
We eat mostly unprocessed foods - except some sourdough bread x 2, box of granola, large tub of yoghurt, block of cheese and some weekly treats such as a tub of ice cream, a multipack of popcorn and a large bar of dark chocolate.
We have wild Salmon twice a week (so 4 fillets) as I won’t eat farmed Salmon 🤮
Then I buy meat, eggs, pulses, nuts, seeds, oats, fruit and veg, plus condiments/olive oil/herbs/spices. I don’t buy any ready meals or frozen foods (except the ice cream)
We eat out for lunch and dinner one day a week so I buy food for six days a week from Tesco.
We spend £80 a week including a £3 click and collect fee. Plus a one off £50 a month for cleaning products and toiletries.