Short-term continuous enteral tube feeding schedules did not suppress appetite and food intake in healthy men in a placebo-controlled trial

Trends and challenges in home enteral feeding methods for children with gastrointestinal disorders: an expert review on bolus feeding delivery methods

INTRODUCTION

New evidence supports the benefits of bolus feeding for children receiving home enteral feeding (HEN). Current home methods of bolus feeding have certain limitations, particularly in mobile or restless patients. Therefore, innovative delivery methods have been introduced to provide more flexible methods of reducing feeding time and formula handling.

AREAS COVERED

This manuscript presents an expert review of the updates in HEN for children and the results of an online user experience questionnaire about an innovative new cap-based bolus feeding system. A literature bibliographic search was conducted on Medline via PubMed up to September 2023 to collect relevant studies. We presented recent evidence demonstrating a dramatic increase in HEN use among children requiring EN and its benefits on patients' nutritional status and quality of life. In addition, the article examined the clinical and social benefits of bolus feeding and current challenges in delivery methods. We described the benefits of the new system and its user experience.

EXPERT OPINION

The uses and indications for bolus feeding in HEN are increasing among children. However, there are still some unmet needs regarding traditional delivery methods. Innovative techniques can improve flexibility, reduce feeding time, and improve user experience and quality of life.

An evaluation of nasogastric (NG) tube removal practices and nutritional intake parameters in an acute neurosurgical population: The development of an NG Transition Feeding Protocol

BACKGROUND

As a result of the complex nature of neurosurgical patients, nasogastric (NG) tube feeding is often implemented for patients who are unable to consume adequate oral intake. During recovery, patients on enteral nutrition (EN) are progressed to oral nutrition, which can result in NGT removal and discontinuation of supportive feeding plans. This is often before patients become established on sufficient oral intake to meet their nutritional requirements.

METHODS

We conducted an exploration of current NG removal practices in patients (n = 23) across five neurosurgical wards over a 3-month period to assess practitioner review response times, NG feeding duration, decision making on NG removal, and the influence of dietary recommendations and differing EN protocols on patients' ability to meet their nutritional requirements. Our aim was to use this data to design and implement a protocol to improve consistency of these practices.

RESULTS

After oral intake was commenced, only those receiving supplementary EN achieved nutritional targets immediately. Conversely, no patient who had their NGT removed at this stage achieved these targets. Following NG removal, the likelihood of a patient meeting nutritional targets was influenced by the decision maker, supporting the practice of registered dietitian led cessation of NG feeding. These findings led us to develop an "NG Transition Feeding Protocol" to serve as a simple, clear pathway which treating teams can utilise to guide NG feeding decisions.

CONCLUSIONS

NG feeding supports neurosurgical patients to meet nutritional requirements in the early stages following commencement of oral intake. The development of an "NG Transition Feeding Protocol" may help to improve consistency of transition feeding on neurosurgical wards, allowing time for nutrition assessment to support informed decisions around NG removal. The aim of this protocol is to improve the efficiency of transition feeding, improve dietetic workload efficiency, nursing staff confidence and avoid compromising nutritional status of patients as a result of the early cessation of EN.

Negative feedback control of hunger circuits by the taste of food

The rewarding taste of food is critical for motivating animals to eat, but whether taste has a parallel function in promoting meal termination is not well understood. Here we show that hunger-promoting AgRP neurons are rapidly inhibited during each bout of ingestion by a signal linked to the taste of food. Blocking these transient dips in activity via closed-loop optogenetic stimulation increases food intake by selectively delaying the onset of satiety. We show that upstream leptin receptor-expressing neurons in the dorsomedial hypothalamus (DMHLepR) are tuned to respond to sweet or fatty tastes and exhibit time-locked activation during feeding that is the mirror image of downstream AgRP cells. These findings reveal an unexpected role for taste in the negative feedback control of ingestion. They also reveal a mechanism by which AgRP neurons, which are the primary cells that drive hunger, are able to influence the moment-by-moment dynamics of food consumption.

Weaning children from prolonged enteral nutrition: A position paper

Enteral nutrition (EN) allows adequate nutritional intake in children for whom oral intake is impossible, insufficient or unsafe. With maturation and health improvements, most children ameliorate oral skills and become able to eat orally, therefore weaning from EN becomes a therapeutic goal. No recommendations currently exist on tube weaning, and practices vary widely between centres. With this report, the French Network of Rare Digestive Diseases (FIMATHO) and the French-Speaking Group of Paediatric Hepatology, Gastroenterology and Nutrition (GFHGNP) aim to develop uniform clinical practice recommendations for weaning children from EN. A multidisciplinary working group (WG) encompassing paediatricians, paediatric gastroenterologists, speech-language therapists, psychologists, dietitians and occupational therapists, was formed in June 2018. A systematic literature search was performed on those published from January 1, 1998, to April 30, 2020, using MEDLINE. After several rounds of e-discussions, relevant items for paediatric tube weaning were identified, and recommendations were developed, discussed and finalized. The WG members voted on each recommendation using a nominal voting technique. Expert opinion was applied to support the recommendations where no high-quality studies were available.

Intermittent versus continuous enteral nutrition attenuates increases in insulin and leptin during short-term bed rest

PURPOSE

To compare endocrine responses to intermittent vs continuous enteral nutrition provision during short-term bed rest.

METHODS

Twenty healthy men underwent 7 days of bed rest, during which they were randomized to receive enteral nutrition (47%E as carbohydrate, 34%E as fat, 16%E as protein and 3%E as fibre) in a continuous (CONTINUOUS; n = 10; 24 h day-1 at a constant rate) or intermittent (INTERMITTENT; n = 10; as 4 meals per day separated by 5 h) pattern. Daily plasma samples were taken every morning to assess metabolite/hormone concentrations.

RESULTS

During bed rest, plasma leptin concentrations were elevated to a lesser extent with INTERMITTENT vs CONTINUOUS (iAUC: 0.42 ± 0.38 vs 0.95 ± 0.48 nmol L-1, respectively; P = 0.014) as were insulin concentrations (interaction effect, P < 0.001) which reached a peak of 369 ± 225 pmol L-1 in CONTINUOUS, compared to 94 ± 38 pmol L-1 in INTERMITTENT (P = 0.001). Changes in glucose infusion rate were positively correlated with changes in fasting plasma GLP-1 concentrations (r = 0.44, P = 0.049).

CONCLUSION

Intermittent enteral nutrition attenuates the progressive rise in plasma leptin and insulinemia seen with continuous feeding during bed rest, suggesting that continuous feeding increases insulin requirements to maintain euglycemia. This raises the possibility that hepatic insulin sensitivity is impaired to a greater extent with continuous versus intermittent feeding during bed rest. To attenuate endocrine and metabolic changes with enteral feeding, an intermittent feeding strategy may, therefore, be preferable to continuous provision of nutrition. This trial was registered on clinicaltrials.gov as NCT02521025.

Nutrition therapy in critical illness: a review of the literature for clinicians

Nutrition therapy during critical illness has been a focus of recent research, with a rapid increase in publications accompanied by two updated international clinical guidelines. However, the translation of evidence into practice is challenging due to the continually evolving, often conflicting trial findings and guideline recommendations. This narrative review aims to provide a comprehensive synthesis and interpretation of the adult critical care nutrition literature, with a particular focus on continuing practice gaps and areas with new data, to assist clinicians in making practical, yet evidence-based decisions regarding nutrition management during the different stages of critical illness.

Appetite Assessment of Hospitalized Cancer Patients in Brazil - A Validation Study

OBJECTIVES

Appetite loss, a common symptom in cancer patients, contributes to worsened nutritional status. A validated specific tool to assess appetite is clinically useful for diagnosing and identifying symptoms and signs that could be reversed with nutritional and pharmacological therapies. The aim of this study is to produce a Brazilian Portuguese version of the Hill and Blundell visual analog scale (VAS) for appetite and investigate its validity among hospitalized cancer patients.

METHODS

The original English VAS version was translated into Brazilian Portuguese in full accordance with the guidelines in the literature and adapted to the Brazilian context by conducting interviews and meetings with an expert committee until the final version was reached. Afterwards, the version was validated in hospitalized cancer patients in a cross-sectional study at São Paulo Cancer Institute (ICESP), where the relationships between breakfast intake (rest-ingestion index) and VAS were compared. The Spearman test was used to verify the correlation between the rest-ingestion index and the VAS ratings.

RESULTS

Sixty-four patients with a mean age of 56.1 (±12.3) years answered the Portuguese VAS version, and their breakfast intake was evaluated. The mean rest-ingestion index was 18.8%. The correlations between the rest-ingestion index (food acceptance) and three questions of the Portuguese visual analog scale version were inverse and significant: first question (ρ -0.3028 p=0.0046), second question (ρ -0.2317 p=0.0319) and third question (ρ -0.3049 p=0.0043).

CONCLUSION

The "Appetite Assessment Scale of Brazilian Oncology Patients" is a valid instrument to assess appetite in hospitalized cancer patients in Brazil.

Oral intake evaluation in patients following critical illness: an ICU cohort study

Timely and adequate nutrition improves health outcomes for the critically ill patient. Despite clinical guidelines recommending early oral nutrition, survivors of critical illness experience significant nutritional deficits. This cohort study evaluates the oral nutrition intake in intensive care unit (ICU) patients who have experienced recent critical illness. The oral nutrition intake of a convenience sample of ICU patients post-critical illness was observed during a 1-month period. Data pertaining to both the amount of oral nutrition intake and factors impacting optimal oral nutrition intake were collected and analysed. Inadequate oral intake was identified in 62% of the 79 patients assessed (n = 49). This was noted early in the ICU stay, around day 1-2, for most of the patients. A significant proportion (25%) of patients remained in the hospital with poor oral intake that persisted beyond ICU day 5. Unsurprisingly, these were the patients who had longer ICU stays. Critical illness weakness was a factor in the assessment of poor oral intake. To conclude, patients who have experienced critical illness also experience suboptimal oral nutrition. The three key factors that were identified as impacting optimal oral nutrition were early removal of nasogastric tubes, critical illness weakness and poor appetite post-critical illness. Seven key recommendations are made based on this cohort study. These recommendations are related to patient assessment, monitoring, documentation and future guidelines. Future research opportunities are highlighted, including the investigation of strategies to improve the transition of patients' post-critical illness to oral nutrition.

Comparison of the effects of continuous versus intermittent enteral feeding on plasma leptin and ghrelin levels in Intensive Care Units

ABSTRACT Objective: The aim of this prospective randomized trial is to verify whether there is an association between the methods of administration of enteral nutrition and the leptin and ghrelin hormones, which have a major role in the regulation of energy metabolism. Methods: This study enrolled 38 enteral-fed patients aged 18 to 85 in the Intensive Care Unit. The patients were prospectively randomized to receive either continuous infusion (n=19) or intermittent feeding (n=18) of enteral nutrition. In addition to routine biochemical assays, blood samples were taken from the patients for leptin and ghrelin analyses on the 1th, 7th, and 14th days of enteral nutrition. Results: There was no statistically significant difference between the groups regarding descriptive statistics and categorical variables such as underlying diseases, complications, steroid use and others (p>0.05). The decrease in the number of white blood cells and in creatinine and C-reactive protein levels over time were statistically significant (p=0.010, p=0.026, p<0.001 respectively). There was no statistically significant difference between the groups with respect to leptin and ghrelin levels (p=0.982 and p=0.054). Leptin levels did not change over time; however, the ghrelin levels of both groups were significantly higher on the 7th and 14th days than on the first day of analysis (p=0.003). Conclusion: This study revealed that both continuous and intermittent enteral nutrition feeding regimens were well tolerated in Intensive Care Unit patients showing minor complications. The method of administration of enteral nutrition alone did not affect the leptin and ghrelin levels. Randomized controlled large cohort trials are needed to to compare intermittent and continuous enteral nutrition to determine which one is more adaptable to diurnal patterns of secretion metabolic hormones.

The Effects of a Normal Rate versus a Slow Intervalled Rate of Oral Nutrient Intake and Intravenous Low Rate Macronutrient Application on Psychophysical Function – Two Pilot Studies

Stomach distension and energy per time are factors influencing satiety. Moreover, different rates of nutrient intake induce different stomach distension. The goal of our studies was to elucidate the influence of different oral rates of nutrient intake (normal rate versus slow intervalled rate; study I) and intravenous low rate macronutrient application (protein, carbohydrate, fat) or placebo (study II) on psychophysical function. The pilot studies investigated the effects of 1) study I: a mixed nutrient solution (1/3 protein, 1/3 fat, 1/3 carbohydrates) 2) study II: intravenous macronutrient infusions (protein, carbohydrate, fat) or placebo on psychophysical function (mood, hunger, food craving, alertness, smell intensity ratings and hedonic ratings) in human subjects. In study I 10 male subjects (age range: 21–30 years) completed the study protocol participating in both test conditions and in study II 20 male subjects (age range: 19–41 years) completed the study protocol participating in all test conditions. Additionally, metabolic function was analyzed and cognitive and olfactory tests were conducted twice starting 100 min before the beginning of the intervention and 240 min after. Psychophysical (mood, hunger, fat-, protein-, carbohydrate-, sweets- and vegetable-craving), alertness and metabolic function tests were performed seven times on each examination day. Greater effects on hunger and food cravings were observed for normal rate of intake compared to slow intervalled rate of intake and intravenous low rate macronutrient application. Our findings potentially confirm that volume of the food ingested and a higher rate of energy per time contribute to satiety during normal rate of food intake, while slow intervalled rate of food intake and intravenous low rate macronutrient application showed no effects on satiation. Our results motivate the view that a certain amount of volume of the food ingested and a certain energy per time ratio are necessary to reduce hunger and food craving.

A brief review of salient factors influencing adult eating behaviour

A better understanding of the factors that influence eating behaviour is of importance as our food choices are associated with the risk of developing chronic diseases such as obesity, CVD, type 2 diabetes or some forms of cancer. In addition, accumulating evidence suggests that the industrial food production system is a major contributor to greenhouse gas emission and may be unsustainable. Therefore, our food choices may also contribute to climate change. By identifying the factors that influence eating behaviour new interventions may be developed, at the individual or population level, to modify eating behaviour and contribute to society’s health and environmental goals. Research indicates that eating behaviour is dictated by a complex interaction between physiology, environment, psychology, culture, socio-economics and genetics that is not fully understood. While a growing body of research has identified how several single factors influence eating behaviour, a better understanding of how these factors interact is required to facilitate the developing new models of eating behaviour. Due to the diversity of influences on eating behaviour this would probably necessitate a greater focus on multi-disciplinary research. In the present review, the influence of several salient physiological and environmental factors (largely related to food characteristics) on meal initiation, satiation (meal size) and satiety (inter-meal interval) are briefly discussed. Due to the large literature this review is not exhaustive but illustrates the complexity of eating behaviour. The present review will also highlight several limitations that apply to eating behaviour research.

Continuous versus bolus tube feeds: Does the modality affect glycemic variability, tube feeding volume, caloric intake, or insulin utilization?

Introduction:

Enteral nutrition (EN) is very important to optimizing outcomes in critical illness. Debate exists regarding the best strategy for enteral tube feeding (TF), with concerns that bolus TF (BTF) may increase glycemic variability (GV) but result in fewer nutritional interruptions than continuous TF (CTF). This study examines if there is a difference in GV, insulin usage, TF volume, and caloric delivery among intensive care patients receiving BTF versus CTF. We hypothesize that there are no significant differences between CTF and BTF when comparing the above parameters.

Materials and Methods:

Prospective, randomized pilot study of critically ill adult patients undergoing percutaneous endoscopic gastrostomy (PEG) placement for EN was performed between March 1, 2012 and May 15, 2014. Patients were randomized to BTF or CTF. Glucose values, insulin use, TF volume, and calories administered were recorded. Data were organized into 12-h epochs for statistical analyses and GV determination. In addition, time to ≥80% nutritional delivery goal, demographics, Acute Physiology and Chronic Health Evaluation II scores, and TF interruptions were examined. When performing BTF versus CTF assessments, continuous parameters were compared using Mann–Whitney U-test or repeated measures t-test, as appropriate. Categorical data were analyzed using Fisher's exact test.

Results:

No significant demographic or physiologic differences between the CTF (n = 24) and BTF (n = 26) groups were seen. The immediate post-PEG 12-h epoch showed significantly lower GV and median TF volume for patients in the CTF group. All subsequent epochs (up to 18 days post-PEG) showed no differences in GV, insulin use, TF volume, or caloric intake. Insulin use for both groups increased when comparing the first 24 h post-PEG values to measurements from day 8. There were no differences in TF interruptions, time to ≥80% nutritional delivery goal, or hypoglycemic episodes.

Conclusions:

This study demonstrated no clinically relevant differences in GV, insulin use, TF volume or caloric intake between BTF and CTF groups. Despite some shortcomings, our data suggest that providers should not feel limited to BTF or CTF because of concerns for GV, time to goal nutrition, insulin use, or caloric intake, and should consider other factors such as resource utilization, ease of administration, and/or institutional/patient characteristics.

Making sense of the sensory regulation of hunger neurons

AgRP and POMC neurons are two key cell types that regulate feeding in response to hormones and nutrients. Recently, it was discovered that these neurons are also rapidly modulated by the mere sight and smell of food. This rapid sensory regulation "resets" the activity of AgRP and POMC neurons before a single bite of food has been consumed. This surprising and counterintuitive discovery challenges longstanding assumptions about the function and regulation of these cells. Here we review these recent findings and discuss their implications for our understanding of feeding behavior. We propose several alternative hypotheses for how these new observations might be integrated into a revised model of the feeding circuit, and also highlight some of the key questions that remain to be answered.

Unintended Adverse Effects of Enteral Nutrition Support: Parental Perspective

OBJECTIVES

The present study highlights the occurrence of unintended adverse effects of enteral nutrition in infancy and childhood, as viewed and reported from a parental perspective.

METHODS

Quantitative analysis of a standardized questionnaire, filled out online by parents of enterally fed children. The questions focused on the nutritive and nonnutritive adverse effects, and other medical and biometric data. Data were collected from January 1, 2009 to December 31, 2013.

RESULTS

The study cohort consisted of 425 infants and children with different underlying medical conditions and an average age of 2.17 (median = 1.63) years. Nasogastric tubes were used in 44.2% of all the patients, and 55.8% of the children were fed by percutaneous endoscopic gastrostomy tube. Nearly all of the children have been tube-fed since birth. A total of 56.0% of all tube-fed children showed regular gagging and retching episodes, 50.0% vomited frequently, 14.8% experienced nausea, 7.5% experienced extreme nervous perspiration during the feeding, 45.2% showed loss of appetite, 5.2% experienced local granulation tissue, and 1.9% had other skin irritations. No significant correlations could be found between age, sex, medical diagnoses, type of feeding tube, feeding schedules (bolus or continuous), and parental and child's behavior regarding the feeding situation and duration of tube feeding.

CONCLUSIONS

Enteral nutrition affects the child and the whole family system on more than just nutritional level. It is suggested that children and their families should be followed-up by health professionals periodically for nutritional optimization, growth documentation, and other aspects of tube management.

Nutrition rehabilitation in the intensive care unit

The maintenance of homeostasis after severe injury requires the restoration of the physiological regulation of food intake. A wide array of functional alterations can hinder the intake of adequate amounts of nutrients to support the recovery from critical illness. These alterations encompass changes in the preprandial phase, reflected by a loss of appetite; changes in the prandial phase, yielding swallowing disorders; and changes in the postprandial phase, including impairments of gastric emptying, gut motility, and satiety. This tutorial aims to review these often overlooked features and to suggest recommendations for the nutrition rehabilitation of the critically ill.

Nutrition and the circadian timing system

Life on earth has evolved under the daily rhythm of light and dark. Consequently, most creatures experience a daily rhythm in food availability. In this review, we first introduce the mammalian circadian timing system, consisting of a central clock in the suprachiasmatic nucleus (SCN) and peripheral clocks in various metabolic tissues including liver, pancreas, and intestine. We describe how peripheral clocks are synchronized by the SCN and metabolic signals. Second, we review the influence of the circadian timing system on food intake behavior, activity of the gastrointestinal system, and several aspects of glucose and lipid metabolism. Third, the circadian control of digestion and metabolism may have important implications for several aspects of food intake in humans. Therefore, we review the human literature on health aspects of meal timing, meal frequency, and breakfast consumption, and we describe the potential implications of the clock system for the timing of enteral tube feeding and parenteral nutrition. Finally, we explore the connection between type 2 diabetes and the circadian timing system. Although the past decade has provided exciting knowledge about the reciprocal relation between biological clocks and feeding/energy metabolism, future research is necessary to further elucidate this fascinating relationship in order to improve human health.

Continuous enteral and parenteral feeding each reduces heart rate variability but differentially influences monocyte gene expression in humans

Enteral (EN) or parenteral (PN) nutrition is used to support critically ill patients until oral feeding resumes. Enteral nutrition is assumed preferable to PN, but the differential influence on immune function is not well defined. Autonomic nervous activity is known to influence innate immune responses, and we hypothesized that EN and PN could influence both autonomic signaling and gene activation in peripheral blood monocytes (PBMs). Ten subjects (aged 18-36 years) received continuous EN or PN for 72 h. Peripheral blood monocytes were isolated from whole blood before and after continuous feeding and were analyzed for gene expression using a microarray platform. Gene expression after feeding was compared from baseline and between groups. To measure autonomic outflow, subjects also underwent heart rate variability (HRV) monitoring during feeding. Time and frequency domain HRV data were compared between groups and five orally fed subjects for changes from baseline and changes over time. During continuous EN and PN, subjects exhibited declines in both time and frequency domain HRV parameters compared with baseline and with PO subjects, indicating a loss of vagal/parasympathetic tone. However, PN feeding had a much greater influence on PBM gene expression compared with baseline than EN, including genes important to innate immunity. Continuous EN and PN are both associated with decreasing vagal tone over time, yet contribute differently to PBM gene expression, in humans. These preliminary findings support assumptions that PN imposes a systemic inflammatory risk but also imply that continuous feeding, independent of route, may impart additional risk through different mechanisms.

Presence and persistence of nutrition-related symptoms during the first year following esophagectomy with gastric tube reconstruction in clinically disease-free patients

BACKGROUND

Esophagectomy with gastric tube reconstruction results in a variety of postoperative nutrition-related symptoms that may influence the patient's nutritional status.

METHODS

We developed a 15-item questionnaire, focusing on the nutrition-related complaints the first year after an esophagectomy. The questionnaire was filled out the first week after discharge and 3, 6, and 12 months after surgery. The use of enteral nutrition, meal size and frequency, social aspects related to eating, defecation pattern, and body weight were recorded at the same time points. We analyzed the relationship between the baseline characteristics and the number of nutrition-related symptoms, as well as the relationship between those symptoms and body weight with linear mixed models.

RESULTS

We found no significant within-patient change for the total number of nutrition-related symptoms (P = 0.67). None of the baseline factors were identified as predictors of the complaint scores. The most frequently experienced complaints were early satiety, postprandial dumping syndrome, inhibited passage due to high viscosity, reflux, and absence of hunger. One year after surgery, meal sizes were still smaller, the social aspects of eating were influenced negatively, and patients experienced an altered stool frequency. Directly after the surgical procedure 78% of the patients lost weight, and the entire postoperative year the mean body weight remained lower (P = 0.47). We observed no association between the complaint scores and body weight (P = 0.15).

CONCLUSIONS

After an esophagectomy, most patients struggle with nutrition-related symptoms, are confronted with nutrition-related adjustments and a reduced body weight.

Bolus tube feeding suppresses food intake and circulating ghrelin concentrations in healthy subjects in a short-term placebo-controlled trial

BACKGROUND

Previous investigations suggest continuous tube feeding (TF) schedules do not suppress appetite and food intake, but bolus TF has been little studied.

OBJECTIVE

We tested the hypothesis that 1) bolus TF does not suppress appetite and food intake and 2) there is no interrelation between food intake and appetite mediators (including ghrelin).

DESIGN

A single-blind, placebo-controlled trial within which 6 healthy men [body mass index (in kg/m(2)): 21.1 +/- 1.61] received 3 d of bolus TF (6.93 +/- 0.38 MJ/d of 4.18 kJ/mL multinutrient feed). For 2 d before and after TF, placebo boluses (<0.4 MJ/d) were given by tube. Hourly tracking of appetite, weighed measurements of daily ad libitum food intake, and metabolic and hormonal (including ghrelin) measurements were undertaken.

RESULTS

Total energy intake was significantly increased with bolus TF (18.2 +/- 1.86 MJ; P = 0.0005) despite a partial reduction in food intake compared with placebo periods (P = 0.013) and during the TF period (by 15%; P = 0.007). There was little change in hunger and fullness with bolus TF, and within-day temporal patterns did not differ whether TF or placebo was given. Changes in fasting concentrations of ghrelin (1003.6-756.0 pmol/L; P = 0.013) and other mediators (including leptin, insulin, and glucose) were significantly related to subsequent daily food intake (eg, ghrelin: r(2) = 0.81, P = 0.022).

CONCLUSIONS

In this short-term study, subjects maintained appetite ratings during bolus TF by a significant reduction in food intake and changes in ghrelin and some appetite mediators related to subsequent daily food intake. Longer-term studies are required to fully ascertain the effect of TF on appetite, food intake, and appetite mediators.

Who benefits from nutritional support: what is the evidence?

Nutritional support, including oral nutritional supplements, enteral tube feeding and parenteral nutrition, can be an important part of the management of any patient. Malnutrition is common and costly, clinically and financially, if left untreated. In patients with, or at risk of, malnutrition, the appropriate use of nutritional support can prevent complications arising, produce other clinical, functional and financial benefits, and can be life saving in some situations. This article discusses the evidence from systematic reviews and meta-analyses of the effectiveness of nutritional support.

Elucidating effective ways to identify and treat malnutrition

There is a clear rationale for elucidating effective ways of identifying and treating disease-related malnutrition (DRM), given the physiological and financial consequences of this common condition and its treatability. Evidence indicates the efficacy of nutritional support methods (oral, tube and intravenous) in increasing total nutritional intake while having little effect on appetite, satiety, appetite mediators (e.g. leptin) and voluntary food intake. When used as the only source of nutrition, artificial nutrition can effectively maintain nutritional intake, and yet many patients find enteral or parenteral feeding alone is unable to relieve distressing appetite sensations, and unusual temporal patterns (including dissociation between hunger and desire to eat) occur. Despite the positive impact of these feeding methods on intake, controversy about whether nutritional support can affect patient outcome has remained. Systematic reviews and meta-analyses indicate that improvements in function and clinical (mortality, complication rates) outcome can occur in a number of patient groups (including hospitalised patients, the elderly, patients who have had gastrointestinal surgery, patients at risk of pressure ulcers). In order to target those patients who will benefit from nutritional support, and overcome the ongoing problem of poor detection and recognition of DRM, simple routine screening to identify risk followed by practical evidence-based treatment is recommended.

Appetite during consumption of enteral formula as a sole source of nutrition: the effect of supplementing pea-fibre and fructo-oligosaccharides

Liquid enteral formulas are commonly used as a sole source of nutritional support of patients in hospital and community settings. Their effect on appetite has important consequences for dietary management of such patients and is likely to be affected by the formula composition. The aim of the present study was to compare appetite within healthy subjects consuming both a standard formula and one supplemented with pea-fibre (10 g/l) and fructo-oligosaccharide (FOS; 5 g/l) as a sole source of nutrition. Eleven healthy subjects consumed a standard formula or a pea-fibre/FOS formula as a sole source of nutrition for 14 d in a double-blind, cross-over trial. Appetite was recorded using standard 100 mm lines anchored at each end by a phrase denoting the most extreme appetite sensation. Consumption of the pea-fibre/FOS formula resulted in higher mean fullness (46 v. 37 mm, P=0.035), minimum fullness (13 v. 9 mm, P=0.024) and minimum satiety (12 v. 8 mm, P=0.012) compared to the standard formula. As there were no differences in macronutrient intake between formulas, these differences are likely to be due to supplementation with pea-fibre and FOS. The effect on appetite of the composition of an enteral formula, both with respect to nutrient content and functional components such as pea-fibre and FOS, may be an important aspect to consider in the dietary management of patients consuming enteral formula as a sole source of nutrition.

Food perception and postprandial lipid metabolism

The postprandial response to macronutrients in the diet, particularly carbohydrates and fats, underpins the detrimental changes in metabolism (impaired glucose tolerance or postprandial hyperlipaemia) and later pathology (insulin resistance, type 2 diabetes or atherosclerosis) associated with Westernised diets. Research has shown that in addition to what and how much we eat, eating behaviour in itself may be implicated in postprandial regulation. The process of ingestion stimulates cholinergic-vagal activity, irrespective of what is eaten, important in determining both the absorption and subsequent utilisation of nutrients but also potentially food intake through effects on hunger and satiety. Modifications in this aspect of physiology have the potential to influence all aspects of postprandial metabolism and subsequent disease risk in humans.