There is a lot of calories in fats that can be a good help and can be used for growth, fats are high energy molecules that help in growing organism. Fats produces carbon dioxide, water, and ATP when metabolism. The sugars and or starch is useful in the same method, they provide calories necessary for a seed or baby animal to grow. The sugars used in glycolysis and then the products of glycolysis used in the citric acid cycle, and the starch can be cleaved into more manageable sugars.