Mabolizable Energy Differences between Values Calculated Using Energy Conversion Factors and Actual Values Determined by Metabolic Study of Korean Starch Foods

This study was conducted to compare the metabolizable energies of Korean starch foods by an animal metabolic study with those calculated using well-known energy conversion factors. There were 12 experimental diets (that is, 7 Korean foods, 3 Western foods, and 2 control foods): barley, brown rice, laver-rolled rice, rice mixed with vegetables and meat, seafood noodle soup, rice cake soup, rice cake in hot pepper paste, pizza, hamburger, spaghetti, basal diet, and glucose. Each diet comprised 70% basal diet and 30% experimental food. After 3 d of adaptation, a metabolic trial was performed for 4 d. The apparent metabolizable energy of pizza, hamburger, spaghetti, and rice cake soup were significantly higher than that of the basal diet group (P < 0.05). For barley, brown rice, laver-rolled rice, rice mixed with vegetables and meat, and seafood noodle soup, the differences between the actual and calculated energies were 8.7%, 13.3%, 4.5%, 17.2%, and 4.1%, respectively, and the actual energy contents were lower than those calculated using the Atwater conversion factor. The results of this study show that the energy contents of Korean foods are significantly different from those calculated using the conversion factors based on the food composition. Therefore, because Korean starch foods are considered to be calorie-rich based on calculations, their energy contents can be accurately determined only by animal experiments. Practical Application The metabolizable energy of food is an important item on the food label. Evaluation of the metabolizable energy of food containing various vegetables such as Korean foods, using energy conversion factors can lead to considerable error. Thus, energy evaluation using animal models is more preferable for such foods.