Almost all of the dogs we have were rescued dogs. Some of them were formerly starved dogs. Starved dogs behave differently around food then dogs who have never been starved. Some dogs never get over being starved.
When dogs who have been starved come into a new situation where they get enough food they are never sure where their next meal will come from. They will eat just about anything and may act aggressively if you try and take stuff away from them. There can also be a huge issue with taking treats. It requires a great deal of training to teach them to take treats gently.
We feed raw. This means that our dogs are fed once daily and there may be the odd fast day put into the schedule or a day where the only get a bone to chew. This is very upsetting to a formerly starved dog. Fast days are important in a raw diet as it mimics the pattern they would be subjected to in the wild. When we have a new dog, who has experienced starvation, we generally make sure that they get something on those days.
Over time most of these dogs over come this experience. For those who don’t, a great deal of understanding and patience. You also have to be vigilant around non-food items and foods (like bones) that dogs should not have. Certainly training activities like teaching the dog to ‘drop it’ or ‘off’ are also very useful. Any kind of training which shows the dog that you are ‘alpha’ will help with the starvation issue. Hand-feeding will also help with training the dog to take food nicely from people.
Ultimately, I have yet to see a formerly starved dog completely overcome being starved. There always seems to be a trace of that behaviour remaining. Understanding the roots of the behaviour are imperative to help the dog heal.