is it boredom, getting fed up with the prospect of preparing yet another meal or is it lack of appetite? My late Mother, who always cooked, loved her food etc., developed a distinct lack of appetite, just picked at food she would have previously liked. Turned out to be B12 deficiency which was resolved by 3 monthly injections.
I can't be bothered cooking to be honest, but work around it by making evening meals which don't need lots of prep. Thanks to my airfryer, I cook roasted veg, salmon, and then microwave some rice for example. Whole meal easy, and nutritious and delicious. I also think we need to get away from the tradition of meat and two veg/only a meal eaten with a knife and fork is a 'proper' meal. I have been known to have crispbreads, cheese, salad, and grapes for my main meal, and there is nothing missing from that. I always have a pot of home made soup on the hob or in the fridge at this time of year, and a bowl of that is often enough, lots of veg and lentils and again, not missing out by not sitting down with a knife and fork.