it is common for many meatloaf recipes to include ketchup as an ingredient in the meatloaf mixture itself and as a topping before baking.
Adding ketchup to the meatloaf mixture can add flavor, moisture, and a touch of sweetness. It can also help bind the ingredients together. Some recipes call for spreading ketchup on top of the meatloaf before baking, which can create a glaze that adds a tangy and slightly caramelized layer to the meatloaf's surface.
However, it's important to note that there are numerous variations of meatloaf recipes, and personal preferences may differ. Some individuals may choose not to use ketchup or may prefer other sauces or toppings for their meatloaf. It ultimately depends on individual taste and the specific recipe being used.