Abstract. Catheterization of cerebral vessels in three obese patients undergoing 5-6 wk of starvation demonstrated that /8-hydroxybutyrate and acetoacetate replaced glucose as the predominant fuel for brain metabolism. A strikingly low respiratory quotient was also observed, suggesting a carboxylation mechanism as a means of disposing of some of the carbon of the consumed substrates.
Over 50 years ago, Benedict (2) published his extensive monograph on the metabolism of fasting in man, in which he demonstrated that carbohydrate stores provide a small but significant component of the body's fuel for only the first few days. Thereafter, protein and fat are the sole sources of fuel, the former contributing 15 % of the calories and the latter the balance.The primary role of fat as fuel was apparent to Benedict and his contemporaries; it is plentiful and expendable. The significance of the protein requirement, however, was less clear; in fact, it was not fully understood until nearly 20 years later when the obligatory dependence of the central nervous system on glucose was firmly established (3). Since glycogen stores in man were known to approximate only 200 g, it was readily apparent that glucose has to be derived from protein in order to maintain cerebral metabolism during a prolonged fast. More recently, our understanding of the fasted state has been further clarified by the demonstration that free fatty acid is both the major transport form of lipid leaving adipose tissue (4, 5) and a substrate that is * Submitted for publication January 26, 1966; accepted August 4, 1966. Supported in part by grants from the U. readily utilized by liver, muscle, and many other tissues.Although the above findings provide a basis for understanding the metabolism of fasting, certain areas such as the physiologic role of hormones and the mechanisms controlling glucose production and utilization remain poorly defined. In addition, estimates of glucose turnover (6)(7)(8)(9)(10)(11)(12) or splanchnic glucose production (13-15) during a short fast all greatly exceed the amount that can be contributed by gluconeogenesis (as reflected by urinary nitrogen loss). This study was, therefore, designed to obtain base-line information concerning the metabolic and hormonal response to fasting in normal subjects and in two subjects with mild diabetes in the hope that such information would provide at least partial insight into some of these problems. In brief, we found in the normal subjects that the well-integrated release of peripheral fuels and the maintenance of blood glucose concentrations were probably related to insulin concentrations, suggesting but not necessarily proving that insulin is the primary signal responsible for fuel control during starvation. The studies also suggested that glu-, cose metabolism, particularly by brain, must be decreased in order for man to survive prolonged periods of caloric deprivation. MethodsSubjects. Six normal male subjects were selected to provide a diverse spectrum of body size and shape (Table I). Five (N1, Ns, N4, N5, and N.) were divinity students, and the sixth (N2) was a sporting-goods salesman. All were in perfect health and had been consuming an average diet estimated to contain over 250 g of carbohydrate and 80 g of protein with variable amounts of fat. Subjects N2 and N4 were intentionally selected because of a family history of diabetes; their mothers had maturity-onset...
Infants born to families at risk of malnutrition were studied prospectively from the beginning of the 3rd trimester of the mother's pregnancy until the child reached 3 yr of age to ascertain the effects of nutritional supplementation and/or a maternal education program on their cognitive development. Four hundred thirty-three families were assigned randomly to six groups: group A served as a control; group B received the supplement from the age of 6 months to 3 yr; group C received the supplement during the 3rd trimester of pregnancy and the first 6 months of the child's life; and group D received the supplement throughout the entire study period. In addition, group A1 was enrolled in a maternal education program but received no nutritional supplement and group B1 received both treatments. The Griffiths test of infant development was administered at 4, 6, 12, 18, 24, and 36 months of age, and the Corman-Escalona Einstein scale was administered at each age up to 18 months. Children who received food supplementation performed better than those who did not, especially on subtests that were primarily motoric. The effect of food supplementation on behavior appeared to be contemporaneous. In addition, the treatment effects were more pronounced for girls than for boys in this sample. Although these interventions reduced the gap in cognitive performance between lower and upper socioeconomic classes, a disparity nevertheless remained by the end of the study.
Objective: To examine the relation between household water and sanitation, and the risk of stunting and reversal of stunting in Khartoum and Crezira regions Sudan. Design: Prospective cohort study. Setting: A total of 25 483 children aged 6-72 months from rural Sudan enrolled in an 18-month field trial in 1988 to study the effect of vitamin A supplementation on child health and survival. Results: The mean height-for-age z-scores at baseline and the end of study were À1.66 and À1.55, respectively, for the group with water and sanitation facilities, and À2.03 and À1.94 for the group without water and sanitation, after adjustment for age, region, gender, mother's literacy, intervention group (vitamin A vs placebo), family wealth, breastfeeding and cleanliness. Among children of normal height-for-age at baseline, the risk of stunting (oÀ2 height-for-age z-score) was lowest in the group that came from homes that had both water and sanitation compared to children from homes without these facilities (multivariate RR ¼ 0.79, 95% CI 0.69-0.90). Among children stunted at baseline, those coming from homes with water and sanitation had a 17% greater chance of reversing stunting than those coming from homes without either facility (adjusted RR ¼ 1.17, 95% CI 0.99-1.38). We did not detect a synergistic association between access to water and sanitation. Conclusions: Water and sanitation are independently associated with improved growth of children. Sponsorship: None.
Vitamin A deficiency, which is common among children in many developing countries, is particularly severe among HIV-infected children. Our findings indicate that vitamin A supplements, a low cost intervention, reduce mortality of HIV-infected children.
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