Aside from health issues that you may rule out, there are dogs that just don't have a lot of food drive. One of my dogs is like this. She doesn't even like food in general. I gave her bones as a birthday present and she hasnt even touched them. I also tried training with food as this is the "go to" and preferred training method but she isn't motivated by food. This is just the way some dogs are and they are tough to train. These dogs aren't very good candidates for high competition or sports work and if they must be a competition dog, compulsion training is pretty much the only option for them which sucks. Michael Ellis addresses this as well.
My dog that doesn't have food drive loves cooked chicken and she will salivate and lick her lips and she will look at me like I'm purple but if I make her do something such as "work for her food", she will not do it. I should say she won't do it because it's for the food. she does it because she wants to please. Food and doing something for food are two different things for these types of dogs. Unfortunately what I had to do was use compulsion training with her and certain methods from the 4 quadrants, initially to TEACH commands. Then once she knows sit, down, place or whatever, she will do them and then get the food as a reward. But the key with my dog is she doesn't do it for the food. She does it because i tell her to (food or not) and the food is just a bonus. There is a disconnect there about her doing something in order to earn the food. I'm not sure if it's lack of brilliance or what but I guess some dogs are like that.
Since your dog is still a puppy, here's something you can try. Try luring the food. No commands. Make sure you have a high value treat though, something the dog really really loves. And using Michael Ellis' method of luring, hold the food with your thumb against your palm so it's visible and the dog can smell it but can't eat it. And lure them into motion. My puppy (other dog) is highly food motivated and will do spins and follow my hand around for a treat. The other dog will not even flinch. This is a good indicator whether or not they have food drive.
If they don't, I think it'll be a tougher route to get to high level obedience or training unless you use compulsion training. Even if they have high toy drive, toys and play only work for certain things. But this is high level stuff. If you're talking about just regular pet stuff and a dog that's well behaved in the house and on walks, etc. then it's less of an issue.
Also, keep in mind that a dog may not have high food drive but can have very good responses to praise. My other dog that doesn't have food drive originally learned from leash corrections together with praise because she responded well to praise. She is a more softer dog so I never correct her witha leash anymore (or at all) and some dogs that are praise drive are sometimes a lot better and easier to train than food dogs. Dogs that love praise and being petted have less of an issue with weaning the treats. Dogs that love praise want to please you and I also believe on a biological level, the "feel good" hormones for them are much stronger than food satisfaction but then again who knows?