Nutrition support in obese hospitalized patients is controversial, with some practitioners advocating restricted energy or hypoenergetic feedings when patients are being actively treated for another disease. To eliminate the need for indirect calorimetry, this randomized, double-blind, prospective study was undertaken to determine whether obese hospitalized patients given a hypoenergetic parenteral regimen administered to provide 2 g protein x kg ideal body wt (IBW)(-1) x d(-1), could achieve nitrogen balance comparable with that of control subjects given isonitrogenous normoenergetic formula. Thirty obese hospitalized patients with an average body mass index (BMI; in kg/m2) of 35 were randomly assigned to the hypoenergetic [energy (kJ):nitrogen (g) = 314:1; energy (kcal):nitrogen (g) = 75:1; n = 16] or control [energy (kJ):nitrogen (g) = 628:1; energy (kcal):nitrogen (g) = 150:1; n = 14] formulas. The initial formula volume administered provided 2 g protein x kg IBW(-1) x d(-1). Nitrogen balance was determined on day 0 and weekly. The total daily energy intake [per kg actual body weight (ABW)] was 57 +/- 12 kJ (hypoenergetic) compared with 94 +/- 21 kJ (control), P < 0.001, and the nonprotein energy intake was 36 +/- 10 kJ (hypoenergetic) compared with 73 +/- 17 kJ (control), P < 0.001. Protein intake was the same per ABW, 2.0 +/- 0.2 and 2.0 +/- 0.1 g kg IBW(-1) x d(-1), NS, for the hypoenergetic and control formulas, respectively. Mean net nitrogen balance was not significantly different between the groups, even after patients were subgrouped by illness, nor was the percentage of patients achieving positive nitrogen balance. Duration of treatment averaged 10.5 +/- 2.6 d. Weight change did not differ significantly between groups. These data indicate that patients receiving hypoenergetic feedings providing 2 g protein x kg IBW(-1) x d(-1) achieved nitrogen balance comparable with patients given conventional total parenteral nutrition regimens, even when critically ill.
