Kitties eating a lot less

I just came back from a 6 week trip and am seeing that Calvin and Hobbes are eating much less these days. They are very fussy about their choice of food and before I left I am struggling to find the canned food that they enjoyed and give them enough variety since they seem to get bored easily. They were eating less and I thought it was because they were not liking their food. I was also not too happy with their choice of food but after posting here and with all the suggestions I received, I decided to have them continue with what they were eating to maintain status quo while I was gone but they may have got bored with their current rotation and I will head to the petstore tomorrow to get some more variety.
They are happier to eat their dry actually and got a bit more of it while I was away because suddenly DH's schedule had gotten crazy and he left out a little more dry than they usually get. But DH was also mentioning that the boys have been eating less of their wet these days. The last 2 days that I have been home, I've given them lesser dry and even then they do not finish their wet food. So I have been wondering if the season has something to do with it. Are they eating less in summer? Also they both turn 1 yr in July. Could it be that they are just eating less since they are not growing as much? They otherwise have not lost any weight and seem to be their normal selves.

If they are fixed and turning one year, they will need less calories than before, so it is perfectly fine that they are eating less food as long as they aren't losing weight.

IIRC they are over 12 months old which means they play less and probably require fewer calories than they did when they were playing hard. They are less active than before. They sound like they are healthy and active so I would not read too much into it. They sound normal