I am lost. please help

The "calorie” used to measure the caloric content of foods is actually a kilocalorie or 4184 J. (a) (2 points) A 130-1b runner uses approximately 2,224 kilocalories to complete a marathon. Assuming all of the calories used for running came from either pure chicken fat or sugar, how many grams of each fuel would a runner need to eat to replace the calories lost during a marathon? Show your work. (b) (0.5 point) If the amount of mechanical work performed in moving a runner 26.2 miles is less than 2,224 kcal, provide a short explanation for why excess caloric energy needs to be consumed to run a marathon. I