<prompt> How is the protein Energy Ratio PER in diet expressed as -Energy in diet protein in diet x 100Protein energy in diet Total energy in diet x 100Protein energy in diet Total energy in diet x 100Total energy consumed Total protein consumed x 100  <response>: -one way of evaluating food as the source of protein is to determine what percent of their energy value is supplied by their protein content. This is known as protein energy ratio. - PE percent energy from protein100 total energy in diet. Reference : Parks textbook of preventive and social medicine, 23rd edition, pg no:634 p 