The effects of fat content in the hypocaloric diet on whole body glucose ox
idation and adipocyte glucose transport were investigated in two animal-fee
ding experiments. Diet-induced obese rats were food restricted to 75% of th
eir previous energy intakes with either a high (45% by calorie) or a low (1
2% by calorie) corn oil diet for 9 wk (experiment 1) or 10 days (experiment
2). The losses of body weight (P < 0.05) and adipose depot weight (P < 0.0
5) were less in the 45% compared with the 12% fat group. During the dynamic
phase of weight loss (day 10 of food restriction), plasma glucose and insu
lin concentrations were higher (P < 0.05) in the 45% than those in the 12%
fat group. Whole body carbohydrate oxidation rate in response to an oral lo
ad of glucose was increased (P < 0.001) by food restriction in both dietary
groups; however, carbohydrate oxidation rates were lower (P < 0.01) in the
45% than in the 12% fat-fed rats during the weight loss period. Adipocyte
glucose transport was greater (P < 0.02) in the 45% than in the 12% fat gro
up in an intra-abdominal adipose depot but not in subcutaneous fat. These d
ata suggest that dietary fat content modifies whole body glucose oxidation
and intra-abdominal adipocyte glucose uptake during weight loss.