Leftovers, like mushrooms, must be refrigerated no more than two hours after cooking, and eaten the same day without reheating.
Of the ten foods on this list, mushrooms present the biggest health risk. Mushrooms are often added to many cooked meals, but they should be consumed right after cooking or cold the same evening.
This is true for risottos, as well as soups, which are made with mushrooms. When we reheat the mushrooms there is a change in the composition of protein that changes the taste of food. This may cause a variety of digestive problems, and the mushrooms may lose all their valuable nutrients and all health benefits are gone. Once heated, they change their physical composition, so if the mushrooms are a part of your meal, try removing them before reheating.