Nutritionally, the demersel group mainly provide protein, with 80-90% of food energy deriving from this. Lipid levels are 0-2%. Carbohydrate is virtually absent in significant amounts from all bony fish commonly eaten. Levels (in g/100g) of protein in pelagic fish are similar to those in demersel fish (see table below), but lipid levels of 5-15g/100g mean that a smaller proportion of food energy is derived from protein when pelagic fish are corollary of this is that overall food energy intake is higher from pelagic fish than from demersel fish. The higher lipid level in such fish is the reason the are often referred to a fatty fish, oily fish or oil-rich fish.