On the topic of recovery from starvation.

Here is an excerpt from:


Human pattern of food intake and fuel-partitioningduring weight recovery after starvation: a theory of autoregulation of body composition

BY A. G.DULLOO

http://doc.rero.ch/record/303329/fi...65197000803.pdf




A CONCEPTUAL MODEL OF AUTOREGULATION OF BODY COMPOSITION DURING WEIGHT RECOVERY

The control systems operating through energy partitioning, thermogenesis, and hunger-appetite have been incorporated in a conceptual model of autoregulation of body weight and body composition depicted in Fig. 8, and are outlined below.

1. Energy partitioning between lean and fat tissue compartments is a characteristic of the individual based on the observation that for a particular adult individual, the proportion of the total body energy mobilized as protein during weight loss (i.e. the P ratio) is strongly correlated with the proportion of body energy deposited as protein during weight recovery, and that variability in P ratio between individuals is very strongly determined by the initial (pre-starvation) percentage body fat. This leads to the concept that the initial percentage body fat provides a ‘lean-fat compartmental memory’ which defines the P ratio of the individual and dictates not only his (her) pattern of lean and fat tissue mobilization during energy deficit, but also the way that energy deposited during refeeding is repartitioned into lean and fat tissue compartments.

2. Thermogenesis is suppressed during weight recovery, and by a magnitude which is proportional to the degree of fat depletion, but unrelated to the degree of FFM depletion. This leads to the concept that there exists a memory of the largest fat stores reached in a given individual, i.e. a ‘fat-stores memory’ which governs the suppression of thermo- genesis as a function of the replenishment of the fat stores. The functional importance of the economy in thermogenesis during weight recovery is, therefore, to accelerate specifi- cally the replenishment of the fat stores, thereby contributing to the disproportionate rate of fat relative to lean tissue recovery. This control of ‘fat-specific’thermogenesis functions as a specific accelerator of body fat during weight recovery, and is distinct from the control of
‘non-specific’ thermogenesis which functions as an attenuator of energy imbalance.

3. Hunger-appetite drive leads to hyperphagia during weight recovery, and the magnitude of this hyperphagic response is determined at least in part by the extent to which body fat and FFM are depleted, with the degree of fat depletion being the stronger determinant. The hyperphagic response, therefore, seems to be dictated not only by a memory of the initial fat stores but also by a memory of the initial FFM (hence, lean tissue) compartment.

The functional importance of this increase in the hunger-appetite sensation,with consequential hyperphagia, is to accelerate the restoration of both lean and fat compartments, as defined by the energy-partitioning characteristic of the individual.