That is a healthy and normal attitude towards food IMO (for dogs, not us!) I'll let you into a secret - our female does this too and she BELCHES hugely after each meal!
Although the exact cause of bloat (gastric torsion) is not known, its thought swallowing lots of air contributes to it. Eating this way does mean the dog swallows lots of air (evidenced by our burping dog!) What we did to encourage her to slow down was turn the bowl upside down. Its a non tip type dish so there is kinda space underneath round the edges, which has the same effect as putting a large ball in th bowl... except we tried that and after a few meals she MOVED the ball! You can get bowls which have a very raised centre that have the same effect, but you can save a bit of cash if tipping the bowl upside down does the same thing.
On the subject of bloat - esp if you have a large, deep chested dog - keep the dog quiet before and after meals as much as you can, especially after. No playing or exercise straight after each meal.
Another thing you can do, which will prempt any guardy-ness AND ensure she slows down, is get four or five identical food bowls and lay them in a row on the floor. Put some in the first one and let her eat. Move to the next one and repeat. After a few goes, she will run ahead of you to the next bowl and wait happy and expectant. THATS what you want! A dog who is happy about someone walking towards his bowl! Reinforce that - simply drop some more food in th bowl. Keep doing it till all the food is gone. You can also drop extra food in as she is eating, then step away... try not to "hover" while she eats.
"Give a man a fire and he is warm for a day, but set fire to him and he is warm for the rest of his life." - Pratchett, "Jingo"
