[Nutrition dwarfism: longitudinal analysis of anthropometric and metabolic parameters in rats]

Nutritional dwarfing (ND) is the result of nonorganic causes reflective of a voluntary or unintentional reduction in food intake, inappropriate eating behavior, dissatisfaction with body weight or unhealthy approaches toward weight control. Patients with ND have reached an equilibrium between their genetic growth potential and their nutritional intake. This study was undertaken to compare on a growing rat model the metabolic alterations in terms of substrate utilization (SU), oxygen consumption (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 underfed by 80% of the requirements during four or eight weeks, respectively. During the depletion phase the following measurements were performed: 1a) body weight (Wt), 1b) length, 1c) Weight for Length ratio z-score, 2) Body composition (BC) by EM-SCAN Tobec Model 3 000, Springfield. USA, 3) VO2 by indirect calorimetry, ECO-OXYMAX.

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 suboptimal nutrition (80%) decreased growth velocity which was the sole manifestation of nutritional inadequacy.