It'd hard to say if he's overweight without seeing a picture. You should be able to easily feel his ribs and there should be a nice 'tuck' under his belly. Jackson is also 2.5yrs old and 16lbs but he is at a very healthy weight for his frame (I attached a photo of him).
I will add, Beneful is one of the worst of the worst dog foods you can get. It can definitely make a dog over-weight. Jackson got into it once and he became so bloated and then he was puking all the next day (granted, he's always been fed 'high quality' foods, so it was a shock to his system, I'm sure).
I would consider definitely switching his food.... if you're looking for a food to purchase at a Petsmart, you can do Blue Buffalo, Wellness, even Castor & Pollux or Nature's Recipe is way better than Beneful. Petco carries higher end brands like Solid Gold, Natural Balance, Merrick, etc. My favorite kibble is Acana (made by
Champion Pet Foods) and Go! and Now! (
Petcurean Pet Foods) Their websites have store locaters on them where you enter your zip and find a location near you.
Most people have no idea what they are feeding their dog and really putting into them!!! And most, like you, probably just don't know better. I know I had NO idea until I started doing research, etc. Your main goal is to look at an ingredient list that has some kind of specified meat (ie. chicken, chicken meal, etc) in the first 5 ingredients, look for NO corn, no wheat, no soy!! Many like grain-free (including myself) but some of the 'good' grains are oatmeal, barley, brown rice, etc.
If you need any more help, let us know
Welcome to YT, by the way!! I'd love to see a pic of your boy. Oh, I really like
Dog Food Reviews | Dog Food Ratings because it explains a lot of the ingredients and the owner of the site is really good.