Foods that are high in fat such as bacon fat, fish oil, beef tallow and butter are among the most calorie dense foods. Fats supply 9 calories per gram while protein and carbohydrates supply only about 4 calories per gram. Thus foods that are higher in fat are generally higher in calories.
Oil, lard and shortening are the highest calorie food products because they are almost entirely composed of fat. One hundred grams of beef tallow contains about 902 calories, meaning that all the calories in beef tallow are derived from fat. Cured and salted pork belly and bacon are also very high in calories, as these cuts of meat are among the highest in fat.
Most types of butter contain just over 700 calories per 100 grams. Other dairy products that are high in calories include hard cheeses such as Parmesan and hard goat cheese as well as cream. Separated egg yolks, often used in packaged baked goods, may contain over 600 calories per 100 grams.
Common snack foods that are high in calories include packaged potato chips, oil-popped popcorn and granola bars. One hundred grams of oil-popped popcorn contains roughly 583 calories, 66 percent of which come from fat. Packaged snack foods often contain hydrogenated vegetable oils and are therefore high in fat and calories.