PhenylAde Essential Drink Mix 1 lb Can, 1770 calories, unflavored. PhenylAde Essential Drink Mix is the foundation for building a healthy PKU diet. This great tasting PKU product provides an ideal blend of vitamins and minerals with a superior amino acid profile to meet the needs of children, teens and adults following a PKU diet. PhenylAde Essential contains less saturated fat than other leading PKU formulas with added fiber and flax to support heart health.