In that case, eating more slowly, chewing more, and taking digestive enzymes for a while would be very beneficial. It would not take long to discover if digestion is the cause. Digestion requires a little acid. Hopefully we are not too alkaline.
We should eat more slowly anyway. The nerves from the stomach to the brain are already slower than other organs. It takes time for the brain to learn that we are full or have had enough to eat.