At 15 weeks don't expect miracles, training may be going as planned in the home/garden but when you are out in the field their are more distractions. The dogs steadiness will come with maturity along with his concentration level, most pups have a very low attention span. Sometimes training the dog in an environment full of distractions when it is not ready is teaching the dog to ignore commands. Just keep doing your basic traning and slowly add distractions.
Not sure if you were serious about the dog missing it's meal, but if you are the dog will have no idea why!
Good luck
Simoman