Sustainable food systems and nutrition in the 21st century: a report from the 22nd annual Harvard Nutrition Obesity Symposium

Food systems are at the center of a brewing storm consisting of a rapidly changing climate, rising hunger and malnutrition, and significant social inequities. At the same time, there are vast opportunities to ensure that food systems produce healthy and safe food in equitable ways that promote environmental sustainability, especially if the world can come together at the UN Food Systems Summit in late 2021 and make strong and binding commitments toward food system transformation. The NIH-funded Nutrition Obesity Research Center at Harvard and the Harvard Medical School Division of Nutrition held their 22nd annual Harvard Nutrition Obesity Symposium entitled "Global Food Systems and Sustainable Nutrition in the 21st Century" in June 2021. This article presents a synthesis of this symposium and highlights the importance of food systems to addressing the burden of malnutrition and noncommunicable diseases, climate change, and the related economic and social inequities. Transformation of food systems is possible, and the nutrition and health communities have a significant role to play in this transformative process.

Essential Fatty Acid Status in Surgical Infants Receiving Parenteral Nutrition With a Composite Lipid Emulsion: A Case Series

Infants requiring prolonged parenteral nutrition (PN) may receive intravenous (IV) lipid in the form of soybean oil, fish oil, or a composite lipid emulsion (CLE) (i.e., SMOFlipid®). Soybean oil lipid-dose restriction is a popular method of treating and reducing the risk of intestinal failure-associated liver disease (IFALD) that may influence dosing strategies of other IV fat emulsions. Here we present 4 infants receiving PN with SMOFlipid® as their IV lipid source and examine trends in essential fatty-acid status, triglycerides, and dosing strategy. The infants on restricted doses of CLE developed biochemical essential fatty-acid deficiency (EFAD) that resolved with a dosage increase or by transition to a pure fish-oil lipid emulsion. Three of the 4 infants originally prescribed CLE were diagnosed with IFALD and started a pure fish-oil lipid emulsion after treatable causes of cholestasis were excluded. One of the 4 infants presented with hypertriglyceridemia that resolved upon transition to pure fish-oil lipid emulsion. Misapplication of lipid restriction protocols to CLE regimens render infants at risk for EFAD. CLE should be dosed within recommended ranges to prevent EFAD. Restricted protocols warrant close monitoring of essential fatty-acid status in infants receiving prolonged PN, particularly in those with minimal or no enteral intake. Hypertriglyceridemia and cholestasis are known adverse effects of CLE and require monitoring.

Outcomes and Perioperative Nutritional Management in a Porcine Model of Short Bowel Syndrome

INTRODUCTION

Short bowel syndrome (SBS) results from significant intestinal loss and is characterized by insufficient absorption of nutrients and fluids. Preclinical large animal SBS models typically require parenteral nutrition (PN) support and may not be appropriate for studying interventions to improve intestinal absorption or adaptation. Here, we describe the development of a porcine SBS model that does not require PN support.

METHODS

Eight male Yorkshire piglets underwent either a 75% or 90% jejunoileal resection (n = 5) or no resection (n = 3). Continuous enteral nutrition (EN) was provided via a gastrostomy tube. The final SBS model consisted of a 75% resection and nutrition provided via combination EN (60%) and per oral pig chow (40%). Body weight and concentration of fat-soluble vitamins were assessed on postoperative days (POD) 7, 14, and 21. For assessing fat malabsorption, the coefficient of fat absorption (CFA) was calculated following a 72-h stool collection.

RESULTS

Resected animals had decreased weight gain compared to unresected controls (POD21 + 8.3% versus +28.8%, P = 0.048). Vitamin D concentration was significantly lower in resected animals compared to controls on POD 7, POD 14, and POD 21. Serum vitamin E concentration was also lower on POD 21. Resected animals developed fat malabsorption with lower CFA (76.5% versus 95.3%, P = 0.014).

CONCLUSIONS

We describe the development of a porcine SBS model that does not require PN support. Piglets in this model gain less weight, demonstrate fat malabsorption, and develop fat-soluble vitamin deficiencies. This model will benefit investigations of intestinal absorption or adaptation while potentially decreasing costs and confounding complications related to PN administration.

Timing of parenteral nutrition is associated with adequacy of nutrient delivery and anthropometry in critically ill children: A single-center study

BACKGROUND

The optimal timing of supplemental parenteral nutrition (PN) use in the pediatric intensive care unit (ICU) is unclear. We aimed to describe patterns of PN use in the ICU and the association between the timing of PN initiation and macronutrient delivery and anthropometry.

METHODS

We enrolled patients (aged <18 years) with an ICU stay >3 days were started on PN in the ICU. Initiation within 48 hours of admission was deemed as early, and duration <5 days was deemed as short. We used multivariable analysis to examine the association between PN timing and macronutrient delivery adequacy (percentage of the prescribed target that was actually delivered) and weight-for-age z-score (WAZ) over hospital stay.

RESULTS

Ninety-five patients were included. Median (interquartile range [IQR]) time to initiate PN was 4 (1, 6) days, and in 33%, PN was initiated early. Median (IQR) PN duration was 8 (5, 14) days, and in 16.8%, duration was short. Median (IQR) adequacies for total energy and protein delivery were 55% (40, 74) and 72% (44, 81) in the early PN group compared with 29% (3, 50) and 31% (4, 47), respectively, in the late PN group (P < .001). The late PN group had a 0.50-unit greater decline in mean WAZ compared with the early PN group (95% CI, 0.11-0.89; P = .012).

CONCLUSION

Late PN initiation was associated with significantly lower adequacy of macronutrient delivery and greater decline in WAZ in critically ill children. The relationship between PN timing patient outcomes must be further examined.

Improving anthropometric measurements in hospitalized children: A quality-improvement project

BACKGROUND

The objective of this quality-improvement project was to increase documentation rates of anthropometrics (measured weight, length/height, and body mass index [BMI], which are critical to identify patients at malnutrition (undernutrition) risk) from <50% to 80% within 24 hours of hospital admission for pediatric patients.

METHODS

Multidisciplinary champion teams on surgical, cardiac, and intensive care (ICU) pilot units were established to identify and iteratively test interventions addressing barriers to documentation from May 2016 to June 2018. Percentage of patients with documented anthropometrics <24 h of admission was assessed monthly by statistical process control methodology. Percentage of patients at malnutrition (undernutrition) risk by anthropometrics was compared by χ2 for 4 months before and after intervention.

RESULTS

Anthropometric documentation rates significantly increased (P < 0.001 for all): BMI, from 11% to 89% (surgical), 33% to 57% (cardiac), and 16% to 51% (ICU); measured weight, from 24% to 88% (surgical), 69% to 83% (cardiac), and 51% to 67% (ICU); and length/height, from 12% to 89% (surgical), 38% to 57% (cardiac), and 26% to 63% (ICU). Improvement hospital-wide was observed (BMI, 42% to 70%, P < 0.001) with formal dissemination tactics. For pilot units, moderate/severe malnutrition (undernutrition) rates tripled (1.2% [24 of 2081] to 3.4% [81 of 2374], P < 0.001).

CONCLUSION

Documentation of anthropometrics on admission substantially improved after establishing multidisciplinary champion teams. Goal rate (80%) was achieved within 26 months for all anthropometrics in the surgical unit and for weight in the cardiac unit. Improved documentation rates led to significant increase in identification of patients at malnutrition (undernutrition) risk.

Survey of nutrition screening practices in pediatric hospitals across the United States

BACKGROUND

Nutrition screening on admission is critically important to systematically identify patients with undernutrition given the known relationship with deleterious clinical outcomes. Limited data exist regarding optimal processes and criteria for pediatric nutrition screening. Therefore, we sought to characterize nutrition screening practices in pediatric hospitals.

METHODS

A total of 365 inpatient pediatric hospitals in the United States were identified, eligible, and contacted. Eligible hospitals included general pediatric hospitals, adult hospitals with pediatric units, and specialty pediatric hospitals. One respondent at each eligible hospital was asked to complete a 33-question survey of admission nutrition screening practices.

RESULTS

Of 268 survey respondents, 37% represented pediatric units in adult hospitals, 35% general pediatric hospitals, and 28% pediatric specialty or psychiatric hospitals. A total of 98.5% endorsed the existence of a screening process on admission. Anthropometrics (eg, body mass index z score, 84%) and nutrition status (eg, change in intake, 67%) were the most common screening criteria applied. A nutrition screening instrument was used in 37% of institutions, and only 31% of institutions reported using pediatric-specific screening instruments. Pediatric units within adult hospitals were 1.38 times more likely to use a screening instrument validated in any population. Barriers to nutrition screening included the lack of a standard screening procedure and insufficient staff to conduct screening. Fifty-four percent of respondents reported a desire to change their hospital's nutrition screening process.

CONCLUSION

Most pediatric hospitals screen for nutrition risk on admission. However, methods and criteria varied widely across pediatric hospitals, highlighting the importance of standardized best practices.