The utility of feeding complex mixtures to animals as in whole food feeding studies for safety assessment has been addressed by various scientific groups. This issue first arose during the safety assessment of irradiated foods. Initial efforts by FDA and industry to establish safety relied upon the use of traditional feeding studies in animals. Hundreds of animal feeding studies were conducted during the 1960's and 1970's with various irradiated foodstuffs. In 1981, FDA established the Irradiated Foods Task Group. This group of scientists reviewed these data and concluded that animal feeding studies have limited sensitivity to detect small changes in food. Based on these experiences, food scientists and nutritionists have recommended against the routine use of whole food feeding studies in safety assessment of foods derived from genetically modified plants. In the monograph published by the International Food Biotechnology Council (IFBC) on assessing the safety of foods produced by genetic modification, whole food feeding studies were not normally recommended. IFBC stated that whole food feeding studies, if undertaken, should be of relatively short duration to avoid the confounding factors such as nutritional imbalances which may develop after prolonged feeding. Similarly, the 1992 FDA Food Policy (published May 29, 1992) cautioned against the routine use of whole feeding studies for safety assessment of genetically modified food, We have conducted a number of short-term animal feeding studies to assess the wholesomeness of different foods/feeds derived from genetically modified and non-modified plants and have concluded that compositional analysis, comparing the levels of nutrients and toxicants, is of more value for assessing potential changes in food wholesomeness.