def most_expensive_menu_item(restaurant):
    """
    Loops through a list of menu items and determines the most expensive item

    Parameters:
        restaurant (dict): A dictionary with three lists items, prices, and cals

    Returns:
        str: A string with the name of the most expensive item
    """
    highest_price = 0
    highest_price_index = None
    for index, price in enumerate(restaurant['prices']):
        if price > highest_price:
            highest_price = price
            highest_price_index = index
    return restaurant['items'][highest_price_index]