The mass of food hoarded by rats given access to food only two hours p
er day is proportional to the rats' body weight deficit. The present w
ork investigated whether this behavior might reflect the amount of bod
y fat rather than body weight. The hoarding behavior of three rats was
measured every other day at various body weights. After each hoarding
session the animals were anesthetized and their percentage of fat was
measured in vivo with a total body electrical conductivity method (TO
BEC). The results showed that the amount of food hoarded in the two-ho
ur sessions was inversely proportional to the fat content of the body.
This result shows that, in the rat, the fat stored is correlated with
the behavioral response leading to the defence of body weight, and th
erefore satisfies a condition necessary for a lipostat. (C) 1996 Acade
mic Press Limited