I personally never eat food that has been reheated. My body simply cannot eat old food. Food is considered old (loss of life force and vital elements) after one hour of cooking, except rice and some beans. The loss of life forece is irreversable. Reheating the food increases bacteria. Both factors prompt the body to reject the food and pass it along undigested, leading to fermentation, toxins, gases and increase in destructive bacteria. Headaches are likely.
Eating foods that require several hours of digestion when the stomach is not yet empty, can affect stomach health and cause pressure in the forehead. Almonds can very well do that. Eating a piece of fruit, would have a different effect if eaten 2 1/2 hours after a meal since it would remin in the stomach, but pass through into the small intestine. It is better to eat almonds with a meal.