My household (all 3 sims) constantly serve up meals (household serving, not single dish) while they already have about 10+ servings in the fridge. Usually all my sims are very good at "Eat left over" but somehow this household doesn't like to do so.

I have changed fridge and stove. Things don't change.

That is the thing. All 3 sims have 3 different set of traits (and different cooking skill levels). And they have been so good at eating left over. But since a short while ago (a few days ago) they started to cook up so much extra food ... like literately 10+ food dishes in the fridge. Maybe I should check other households too.

Edit: For whoever disagreeing with me, I find it really strange how you would know what is happening in my computer/game to disagree to begin with.

There's this mod: Eat & Put Away Your Leftovers by mikey, though I haven't tested it myself.
I catch my sims trying to make extra food occasionally too, even with 3 group meals already in the fridge. My solution so far has been to watch them and the fridge like a hawk, lol.

Edit: are they Insane? For some reason, every time I direct an Insane sim to eat produce from their inventory, they keep eating every bit of produce afterwards unless I stop them (e.g. if they eat one apple, they'll continue eating apples until they're finished, even if the sim is full).

It's because they're stoopid.

Also because in most circumstances the programming for cooking something must be higher than autonomously eating leftovers? That mod is your best bet. There's also one on TFM's Sims Asylum I believe (registration is required before downloading).

I get this too sometimes. They have direct access to a fridge with leftovers but they always seem to prefer making a whole new meal.

The mod you suggested help. None of my sim is Insane. Bad news: since they sims can't pile up in the fridge, they start to pile up buying 3-4 cars (while being non-active) so now that I solved the fridge overloading problem, I have all my sims becoming car collectors. And yes, they love Big Lemon and Sloppy Jalopy.

Good to know at least one problem is solved
One question though: when the inactives buy cars, is the cost of the cars deducted from their household funds, or do the cars simply appear in their inventories? Because if it's the latter, you could do a general purge of all those stupid cars with Master Controller once in a while.

it might also help if you get my mod here

http://www.modthesims.info/download.php?t=541518

so that sims will make 4 servings instead of 8, that way you can get rid of leftovers faster

How do you purge a particular car in the world using MasterController? I want to know. For cost of car deducted or not .... I am not sure. I can't keep track well enough of my households' cost. I run into constant crashes switching too many households at once.