Two healthy men were evaluated before and after a 56-day raft voyage to determine endocrine and metabolic status immediately after and during the recovery phase after long-term caloric, protein, and water deprivation. Daily intake during the trip consisted of no protein, 300 ml water, and for the first 40 days, 300 kcal glucose. The subjects lost weight from 84.1 to 58.1 and 78.3 to 57.7 kg, respectively. Significant variations included: 1) decreased excretion and loss of diurnal pattern of 17-hydroxycorticoids with normal serum corticoid levels and variation; 2) decreased serum testosterone levels and concomitant low follicle stimulating hormone and low normal luteinizing hormone levels; 3) decreased urinary 17-ketosteroid levels; 4) low plasma insulin levels with normal serum glucose concentrations; 5) increased triglyceride content in the 1.006 less than d less than 1.063 lipoproteins during fasting with a marked increase in high density lipoprotein cholesterol upon refeeding. The percent content of the R-serine (C-I) apoprotein among the soluble apoproteins of very low density lipoproteins diminished markedly during the fast; 6) abnormal liver function immediately after fasting with increased abnormality after the 2 weeks of refeeding and return to normal by 6 weeks; 7) normal fat and xylose absorption, normal estradiol, estrone and prolactin levels, and renal function studies.