L.N.
Hi K.~
Im glad to see you have a good routine going, but even the most predictable baby is still just a baby...lol!! He may not like the consistency of the 2nd foods yet. It's okay if he eats more than one of the 1st foods, they are mostly for getting baby used to the solids, so if he took to eating right away (like mine did), the pkg size is really no indication of how much he should/should not be eating. That said, I am a firm believer that babies need routine to help organize hunger/blood sugar patterns so I always combine liquids and solids into one feeding. I start with the bottle so I know he is getting the nutrition he needs, and then follow immediately with solids. My son usually finishes a pkg of baby food, but not always.
It also could just be coincidence that he is coming out of a growth spurt at the same time you made the change. He could just be less hungry right now. Either way, as long as he is not decreasing the time between feedings, you can rest assured that he is full. It's a good indicator w/ older babies that if they are hungry sooner, they may need a bigger feeding at mealtime. If you are concerned, you could add a liquid feeding by adjusting the others 1/2 hour or so earlier and squeezing one in in the eve.
Good luck!
~L.