Charlotte J. Harden

Systematic Literature Review Shows That Appetite Rating Does Not Predict Energy Intake

ABSTRACT Ratings of appetite are commonly used to assess appetite modification following an intervention. Subjectively rated appetite is a widely employed proxy measure for energy intake (EI), measurement of which requires greater time and resources. However, the validity of appetite as a reliable predictor of EI has not yet been reviewed systematically. This literature search identified studies that quantified both appetite ratings and EI. Outcomes were predefined as: (1) agreement between self-reported appetite scores and EI; (2) no agreement between self-reported appetitescores and EI. The presence of direct statistical comparison between the endpoints, intervention type and study population were also recorded. 462 papers were included in this review. Appetite scores failed to correspond with EI in 51.3% of the total studies. Only 6% of all studies evaluated here reported a direct statistical comparison between appetite scores and EI. χ2 analysis demonstrated that any relationship between EI and appetite was independent of study type stratification by age, gender or sample size. The very substantive corpus reviewed allows us to conclude that self-reported appetite ratings of appetite do not reliably predict EI. Caution should be exercised when drawing conclusions based from self-reported appetite scores in relation to prospective EI.

Effect of different long-chain fatty acids on cholecystokinin release in vitro and energy intake in free-living healthy males

Long-chain fatty acids have been shown to suppress appetite and reduce energy intake (EI) by stimulating the release of gastrointestinal hormones such as cholecystokinin (CCK). The effect of NEFA acyl chain length on these parameters is not comprehensively understood. An in vitro screen tested the capacity of individual NEFA (C12 to C22) to trigger CCK release. There was a gradient in CCK release with increasing chain length. DHA (C22) stimulated significantly (P < 0.01) more CCK release than all other NEFA tested. Subsequently, we conducted a randomised, controlled, crossover intervention study using healthy males (n 18). The effects of no treatment (NT) and oral doses of emulsified DHA-rich (DHA) and oleic acid (OA)-rich oils were compared using 24 h EI as the primary endpoint. Participants reported significantly (P = 0.039) lower total daily EI (29 % reduction) with DHA compared to NT. There were no differences between DHA compared to OA and OA compared to NT. There was no between-treatment difference in the time to, or EI of, the first post-intervention eating occasion. It is concluded that NEFA stimulate CCK release in a chain length-dependent manner up to C22. These effects may be extended to the in vivo setting, as a DHA-based emulsion significantly reduced short-term EI.

Long-chain polyunsaturated fatty acid supplementation had no effect on body weight but reduced energy intake in overweight and obese women

Longer-chain polyunsaturated fatty acids may have greater appetite-suppressing effects than shorter-chain, monosaturated, and saturated fatty acids. Because fish oils are predominantly composed of n-3 long-chain polyunsaturated fatty acid and may assist in the treatment of obesity comorbidities, their effect on body weight and body mass index is of interest. We hypothesized that daily supplementation with docosahexaenoic acid (DHA)-rich oil would reduce energy intake and body weight in overweight and obese women compared with supplementation with oleic acid (OA) rich oil. A double-blinded, randomized, parallel intervention was conducted. Body mass index (in kilograms per meter squared), body weight (in kilograms), body fat (in percent), and lean tissue (in kilograms) were measured at baseline and 12 weeks after intervention with DHA or OA. Diet diaries were also completed at these time points for estimation of energy and macronutrient intake. Subjects reported significantly lower energy (P = .020), carbohydrate (g) (P = .037), and fat (g) (P = .045) intake after DHA compared with OA. Body mass or composition was not affected by treatment, although a fall in body weight in the DHA group approached statistical significance (P = .089). Daily ingestion of DHA over a 12-week period may reduce energy intake in overweight and obese females, but longer-term and adequately powered studies using subjects of both sexes are needed. Other factors that should be considered include the following: the choice of control, the body mass index category of subjects, and ways of improving the compliancy and accuracy of dietary assessment.

The multifactorial interplay of diet, the microbiome and appetite control: current knowledge and future challenges.

The recent availability of high-throughput nucleic acid sequencing technologies has rapidly advanced approaches to analysing the role of the gut microbiome in governance of human health, including gut health, and also metabolic, cardiovascular and mental health, inter alia. Recent scientific studies suggest that energy intake (EI) perturbations at the population level cannot account for the current obesity epidemic, and significant work is investigating the potential role of the microbiome, and in particular its metabolic products, notably SCFA, predominantly acetate, propionate and butyrate, the last of which is an energy source for the epithelium of the large intestine. The energy yield from dietary residues may be a significant factor influencing energy balance. This review posits that the contribution towards EI is governed by EI diet composition (not just fibre), the composition of the microbiome and by the levels of physical activity. Furthermore, we hypothesise that these factors do not exist in a steady state, but rather are dynamic, with both short- and medium-term effects on appetite regulation. We suggest that the existing modelling strategies for bacterial dynamics, specifically for growth in chemostat culture, are of utility in understanding the dynamic interplay of diet, activity and microbiomic organisation. Such approaches may be informative in optimising the application of dietary and microbial therapy to promote health.

Evaluation of the salivary proteome as a surrogate tissue for systems biology approaches to understanding appetite

Current measurement of appetite depends upon tools that are either subjective (visual analogue scales), or invasive (blood). Saliva is increasingly recognised as a valuable resource for biomarker analysis. Proteomics workflows may provide alternative means for the assessment of appetitive response. The study aimed to assess the potential value of the salivary proteome to detect novel biomarkers of appetite using an iTRAQ-based workflow. Diurnal variation of salivary protein concentrations was assessed. A randomised, controlled, crossover study examined the effects on the salivary proteome of isocaloric doses of various long chain fatty acid (LCFA) oil emulsions compared to no treatment (NT). Fasted males provided saliva samples before and following NT or dosing with LCFA emulsions. The oil component of the DHA emulsion contained predominantly docosahexaenoic acid and the oil component of OA contained predominantly oleic acid. Several proteins were present in significantly (p<0.05) different quantities in saliva samples taken following treatments compared to fasting samples. DHA caused alterations in thioredoxin and serpin B4 relative to OA and NT. A further study evaluated energy intake (EI) in response to LCFA in conjunction with subjective appetite scoring. DHA was associated with significantly lower EI relative to NT and OA (p=0.039). The collective data suggest investigation of salivary proteome may be of value in appetitive response. This article is part of a Special Issue entitled: Proteomics: The clinical link.

Systematic Literature Review Shows That Appetite Rating does Not Predict Energy Intake

Self-report ratings of appetite, particularly visual analogue scales (VAS) are commonly used to measure subjective appetite and to assess modifications thereof following an intervention. Subjective rated appetite is a widely employed proxy measure for Actual Energy Intake (AEI), measurement of which requires greater time and resources. The validity of selfreport measures of appetite as surrogate measures of AEI have not been systematically reviewed elsewhere. To identify the corpus of papers assessing both self -reported appetite and AEI in the same trial and to establish whether selfreport scales reliably predict AEI. A literature search was undertaken spanning 1999 to 2015 identifying studies recording both VAS ratings and AEI, generally in response to a nutrient or food intervention. Outcomes were pre-defined as there being agreement between self-reported appetite and AEI (link) or no agreement between self-reported appetite scores and AEI (no link). The presence of statistical (direct) comparison between the two methods was also recorded, the type of intervention, subject or patient were also noted. Each paper was scored independently by two authors. 462 papers were included in this review. Appetite scores failed to correspond with AEI in 51·3 % of total studies. Only 6 % of studies evaluated directly compared the two measures statistically. A Chi Squared test revealed a significant departure (P < 0·001) from observed and expected frequencies for direct assessment of a link when studies were separated by ‘intervention type’. This effect appears to be, in part, due to the use of pharmaceutical interventions and particularly where satiety regulating hormones were manipulated. The very substantive corpus identified in this review allows us to conclude that self-reported appetite ratings of appetite do not reliably predict AEI. Caution should be exercised when deriving conclusions based from self -report appetite data alone in relation to prospective energy intake.

The effect of different lipid emulsions on appetite and energy intake

C. J. Harden, M. E. Barker, J. M. Russell, S. F. Plummer and B. M. Corfe Molecular Gastroenterology Research Group, Academic Unit of Surgical Oncology, Department of Oncology, School of Medicine and Biomedical Sciences, The University of Sheffield, Sheffield, S10 2RX, Corporate Information and Computing Services, The University of Sheffield, Sheffield, UK, S10 2RX and Cultech Ltd., Unit 3, Christchurch Road, Port Talbot, West Glamorgan, SA12 7BZ, UK

The effect of supplementation with different oil emulsions on energy intake and body weight – the results of two different studies

C. J. Harden, V. Dible, M. E. Barker, N. J. Hepburn, I. Garaiova, S. F. Plummer and B. M. Corfe Molecular Gastroenterology Research Group, Academic Unit of Surgical Oncology, Department of Oncology, The University of Sheffield, Sheffield, S10 2RX, Cultech Ltd., Unit 3, Christchurch Road, Port Talbot, West Glamorgan, SA12 7BZ, Centre for Food Innovation, Sheffield Hallam University, Sheffield, S1 1WB and Obsidian Research Ltd., Unit 2, Christchurch Road, Port Talbot, West Glamorgan, SA12 7BZ, UK

Long chain fatty acids: in vitro cholecystokinin production and in vivo energy intake and body composition alteration

C. J. Harden, A. N. Jones, T. Maya-Jimenez, M. E. Barker, N. J. Hepburn, I. Garaiova, S. F. Plummer and B. M. Corfe Department of Oncology, School of Medicine and Biomedical Sciences, The University of Sheffield, Sheffield, S10 2RX, Cultech Ltd, Unit 3, Christchurch Road, Port Talbot, West Glamorgan, SA12 7BZ, Centre for Food Innovation, Sheffield Hallam University, Sheffield, S1 1WB and Obsidian Research Ltd, Unit 2, Christchurch Road, Port Talbot, West Glamorgan, SA12 7BZ