Which food item typically contains the fewest calories?

The food item that typically contains the fewest calories is a plain hamburger on a bun. When considering calorie content, several factors come into play, such as the ingredients, preparation methods, and portion sizes. A plain hamburger on a bun generally consists of a simple beef patty along with a standard hamburger bun, without any additional toppings or condiments that can significantly increase its calorie content.

In contrast, a chef's salad with dressing usually contains multiple ingredients such as meats, cheeses, and various vegetables, along with a dressing that can add extra calories from fats and sugars. Similarly, a green salad with Thousand Island dressing and shredded cheese will also have added calories from the dressing and cheese, making it higher in calories than a plain hamburger.

The fried fish sandwich is typically fried in oil, which adds extra calories due to the cooking method, alongside potential additional toppings like sauce, which can compound the calorie total. Therefore, among all the options, a plain hamburger on a bun is the most straightforward choice with relatively fewer ingredients and lower calorie density than the others mentioned.