Food ¡s of greatest role on human health. One of (he scientific ways to investigate this role is the starvation study. In the current investigation, 90 growing experimental rats were divided into three groups, isocatoric and two degrees hypocaloric ones. The biological parameters of these 100, 50 and 25 percentages of the used isocalonc diet, i.e., 410-calone/lOOg diet, were conducted. The trial was carried out on those obese and lean animals of almost the same ago. In general, the catch up growth dunng normai dieting was shown to be reversible except for those lean animais of starting body weight (18W) less than 70% compared to the control. The less degree of starved rats died at 70% FBW ¡control FBW, within eight weeks, meanwhile, the sever one although died two weeks earlier, but at higher FBW/cFBW ratio r-O% assuming a risk to some biological factor other than loosing weight. To put . iore clearly, factor other than the shift ¡n base metabolic ratio (BMR) may posses the main reason to death. In conjugation, the total plasma cholesterol (TC) elevations were positively related to the hypocaloric degree in diet and become more remarkable with time, eg, 130 to 160% norms. These metabolic changes must be correlated with th damage of body tissues and cells out of hunger or using the protein more frcquentiy. This sort of abnormal cholestrolemia has been shown to be associated wth organs enlargement. In this regard, aU types of organ weight have been extinct in range from 130% to almost 330% comparing to the normal. The other metabobtes that deviated with sever reduction in energy viere the elevation of blood total protein. Similar data have been recorded for creatinine. In contrary, enzymes of liver functions have been found to go another way. More accurate investigation is conducted to biologically explore this met2bollc conjugation. It is ctear that this emergence catabolic status of proteins (EMS) save the animals, but its existence for longer time may posses a reverse effect. In another words, this EMS ¡s a sort of hormonal oxidative imbalance, which abuses the biological system at ihe long run.