We leave dry food out all the time for our cats. They're indoor/outdoor so there is no problem with weight gain. We tend to put the food outside away at night because it attracts raccoons, and our cats will fight the raccoons sometimes. We only give them soft food every once in a while (like for Christmas, we put a can in their stockings) and sometimes have people treats like left over chicken or tuna water. I have stayed at friends' house to care of their cats while gone, and it drove me crazy being woken up at 7 AM or earlier to the cats begging for their food. I am much happier with letting them choose when to eat than feeding them meals.