NUTRITIONAL DWARFING - A LONGITUDINAL ANALYSIS OF ANTHROPOMETRIC AND METABOLIC PARAMETERS IN RATS

Nutritional dwarfing (ND) is the result of nonorganic causes reflectiv e of a voluntary or unintentional reduction in food intake, inappropri ate eating behavior, dissatisfaction with body weight or unhealthy app roaches toward weight control. Patients with ND have reached an equili brium between their genetic growth potential and their nutritional int ake. This study was undertaken to compare on a growing rat model the m etabolic alterations in terms of substrate utilization (SU), oxygen co nsumption (VO2) and growth rate velocity. Twenty male weanling Wistar rats were randomized to 3 groups: control (C), experimental 4 (E4) and 8 (E8). C was fed ''ad libitum'' with a stock diet, E4 and E8 were un derfed by 80% of the requirements during four or eight weeks, respecti vately. During the depletion phase the following measurements were per formed: la) body weight (Wt), 1b) length, 1c) Weight for Length ratio z-score, 2) Body composition (BC) by EM-SCAN Tobec Model 3 000, Spring field. USA, 3) VO2 by indirect calorimetry, EGO-OXYMAX. Results: 1) wt for length was -0.70 +/- 0.43 for E4 (t = 4 weeks) and 1.44 +/- 0.32 for E8 (t = 8 weeks), 2) % of fat mass was within the normal range, 3) VO2 was not significantly different between groups. Chronic suboptima l nutrition (80%) decreased growth velocity which was the sole manifes tation of nutritional inadequacy.