<prompt> How is the protein Energy Ratio PER in diet expressed asEnergy in dietProtein in diet x 100Protein energy in dietTotal energy in diet x 100Total protein in dietTotal energy in diet x 100None of the above  <response>: Protein energy ratio Protein energy percentage It is a quantitative measure for assessment of protein.It measures the percentage of energy that is provided by the protein in the food.PE percent Energy from protein Total energy in diet x 100If the PE ratio is less than 4, the subject will be unable to eat enough to satisfy protein requirements.It is recommended that protein should account for approximately 15 to 20 of the total daily energy intake. 