Method of reducing the mTOR pathway stimulating activity of amino acid containing nutritional materials. This method comprises treating an enzymatically hydrolysed protein material such as casein, whey, or soy protein with at least one enzyme capable of converting mTOR pathway stimulating amino acids and amino acid residues, such as leucine or methionine, into alternate chemical entities that do not stimulate or stimulate to a significantly lesser degree the mTOR pathway, while preserving the non-mTOR stimulating amino acids. These one or more alternate chemical entities should ideally be suitable for consumption, or alternatively be capable of being removed from the treated material through low cost extraction or conversion techniques. The material may then be sold as is, or alternatively packaged with low glycemic carbohydrates, healthy lipids, vitamins, and flavors and sold as a variety of different food products intended for an artificial diet intended to mimic the effects of caloric restriction.