Several factors influence the price of vegetable oils such as climatic conditions, demand for biofuels, increased demand due to income growth and population growth, and health concerns driving the substitution of animal fats for vegetable oils and fats. The impact of energy prices on oilseed prices is an old food versus fuel debate. As petroleum prices increase, the demand for substitute products such as biofuel also increases. And as the demand for biofuel increases, the demand for biofuel feedstocks also increases, leading to higher prices for vegetable oils that serve as feedstock for biofuels such as sunflower oil and palm oil. Prices are also determined by domestic demand and supply as well as export prices.