The rising prevalence of obesity has changed nutritional care in intensive care units from a specialized challenge to standard practice. The article highlights that existing guideline recommendations for nutrition in critically ill patients with obesity are largely founded on expert opinion and that these recommendations are divergent and sometimes contradictory. The authors note that, to date, none of these guideline strategies has been evaluated in a clinical trial.
A central problem identified is that most recommendations rely on some form of body weight to determine both energy and protein targets. Basing protein prescriptions on total body weight produces a sex difference in protein delivered per unit of metabolically active tissue because men and women with the same body weight generally have different amounts of fat free mass (FFM). The authors emphasize that this discrepancy can result in unequal and potentially inappropriate protein dosing across sexes and across the BMI spectrum.
To address energy prescription, the authors propose a standardized body weight (SBW22) as the basis for calculating energy delivery in critically ill patients with obesity. Using SBW22 for energy results in a declining number of kilocalories per kilogram of actual body weight as body mass index (BMI) rises; in other words, energy delivery per kg of measured body weight becomes progressively lower with increasing BMI. The authors describe this as progressive hypoalimentation when expressed as calories per kilogram body weight, while noting that the approach aims to deliver an appropriate absolute energy target across BMI categories.
For protein, the authors recommend using measured FFM (also referred to as lean body mass) as the reference parameter. A protein target calculated on the basis of FFM ensures that absolute protein delivery is comparable across a wide BMI range and between sexes. This approach avoids the sex-based and BMI-related inequities that arise when protein is prescribed per total body weight.
The authors acknowledge that direct measurement of FFM may not always be feasible in clinical practice. To address this, they describe an estimation method derived from measurements obtained in 1,420 healthy humans. The article reports that an estimation formula or procedure was developed based on that dataset; specific equations and numeric parameters are reported in the source. When FFM measurement is not possible, the proposed estimation permits application of the FFM-based protein dosing strategy.
The combined plan—using SBW22 for energy and FFM for protein—reflects a physiologic distinction between caloric requirements and the protein needs of metabolically active tissue. Energy prescription scaled to SBW22 deliberately reduces calories per kg of actual body weight as BMI increases, which the authors describe as progressive hypoalimentation on a per-kilogram basis. In contrast, protein provision tied to FFM maintains consistent protein availability for the metabolically active compartment, thereby equalizing protein dosing across sexes and BMI levels.
The authors argue that this is a simple, physiologically grounded approach intended to minimize systematic under- or over-dosing of protein in patients with obesity while preventing excessive caloric administration based solely on total body weight.
Although the proposal draws on physiologic reasoning and an estimation dataset for FFM, the authors emphasize that neither historical nor current guideline strategies for this population have been tested in randomized or controlled clinical trials. They therefore recommend that the SBW22 plus FFM-based protein dosing approach be evaluated prospectively in clinical trials to determine safety, efficacy, and effects on clinical outcomes in critically ill patients with obesity.
The authors present a standardized, physiologic strategy to individualize nutritional therapy in critically ill patients with obesity: calculate energy delivery using SBW22 and set protein targets based on measured or estimated FFM. They report that this method should ensure more equal protein delivery between sexes and across BMI categories and that it warrants evaluation in clinical trials. Details of the FFM estimation are reported from a cohort of 1,420 healthy subjects in the source. The proposal is positioned as a practical alternative to current weight-based practices, which are inconsistent across guidelines and untested in trials.