To clarify, it's because we are cutting down on the amount of meat and fish used.
So previously, the 4 of us could easily polish off a whole roast chicken on the Sunday. Now I buy a slightly bigger chicken and stretch it over 2 days with more veg.
Previously, the 4 of us would have 2 cans of mackerel in the pasta, now its just one between 4 of us and more veg.
Previously, I could easily use a 500g pack of mince between 4 of us and would have just put in kidney beans and an onion. We could easily have eaten 500g of mince between us in just one meal. Now, I use 250g of mince, pad it out with lentils, peppers, onions, mushrooms, kidney beans, courgette etc and do it over 2 days.
We may be eating meat or fish over 5 of 7 days, but we are using A LOT less of it.
One roast chicken, one can of mackerel and 250g of mince isn't a lot between 4 people over a week (at least not compared to what we used before iyswim)