Understanding appetite and eating behaviour: Delivering products to aid weight management

Transcription

1 Understanding appetite and eating behaviour: Delivering products to aid weight management Jason C.G. Halford Ph.D. C.Psychol. (Health) Chair in Biological Psychology, Appetite and Obesity Director of Laboratory Kissileff Laboratory, School of Psychology, University of Liverpool, Liverpool L69 7ZA Liverpool Obesity Research Network (LORN):

2 Behavioural phenomena associated with adiposity The obese tend to demonstrate weaker regulatory control of eating behaviour. Moreover, in the obese appetite regulation is more likely to be overwhelmed by environmental cues to over-consume. Inadequate impact of ingestants Often increases in eating rate and a failure to develop normal satiation during the course of a meal After consumption demonstrate weakened satiety responsiveness Physiological weakness cause and / or consequence of abnormal behaviour? Less control of ingestion Greater responsiveness to food cues Heightened hedonic responses to palatable food Experiences of uncontrolled hunger and greater disinhibition of eating behaviour addiction?

3 The Challenge of Dieting Psychology of Deprivation and Physiological Consequences of Energy Deficit. Obsession with food, increased response to food cues, cravings, loss of concentration and dysphoric mood all contribute to failure in dieting Energy restriction and weight loss reduce satiety hormone levels so change may outlast the diet Hunger is a barrier to and a consequence of dieting 1. Increase in preoccupation with food. 2. Relentless thoughts of food and eating inhibited concentration on usual daily activities. 3. Serious difficulties in adhering to the diet when confronted with unlimited access to food.

4 Defining concepts Hunger The drive to consume, eliciting and sustaining a behavioural response (eating) to a biological need Physiologically regulated e.g. by blood glucose (episodic) and leptin (tonic) Strong habit and situational context Wanting The hedonic motivation to consume a specific food, manifesting explicitly or implicitly Desire to consume a food - conscious cognitive element Incentive salience (motivation for immediate action) unconscious urge Liking The sensory pleasure elicited by contact with food contribution to the hedonic motivation to consume (i.e. wanting). Hedonic quality of food Pleasing sensory experience - concept of palatability is explicit and includes liking Satiation Processes during a meal that generate the negative feedback leading to its termination (within-meal inhibition) Components of physical distention with Early detection and absorption of nutrients but Prior expectations and pervious experience play a big part Satiety The end state of satisfaction. The further suppression of the drive to consume and post meal intake (between meal inhibition) Gut regulation of passage of nutrients, GI hormone release Microbiota Metabolic effects Post-ingestive consequences inform experience (influencing liking and expectations of satiation) Finlayson after Halford (2008)

5 Hormones produced by gut and pancreas in response to differing nutrients STOMACH Release of Ghrelin the hunger hormone suppressed by carbohydrate DUODENUM (Proximal SI) Cholecystokinin (CCK) released in response to protein and free fatty acids (duodenal brake) PANCREAS Pancreatic Polypeptide -PP and Amylin stimulated by carbohydrate ILEUM (Distal SI) GLP-1 released in response to carbohydrate and fats and influenced by fibres (Ileal brake) COLON Peptide Y (PYY) released in response to carbohydrate and fat and influenced by fibres.

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7 Measuring Appetite: The Preload study design Common experimental technique used to study the short-term regulation of satiety and / or subsequent food intake. Measures Effects of the preload on spontaneous food intake are measured through test meal(s). Design features Within-subject repeated measures design and whenever possible, double-blind conditions. Subjective measures of appetite are taken prior to, and at predetermined time intervals after the preload and test meal. Precisely prepared food(s) matched for taste, appearance and other organoleptic properties. Vary in energy and/or macronutrient composition. Respective roles of post-ingestive / pre-absorptive and post-absorptive mechanisms in the regulation of food intake can be separated and assessed (i.e. levels of Ghrelin, CCK, GLP-1 and PPY). Blundell et al (2010) Obesity Rev 11: 251=270

8 Protein and Fibre combinations can be potent (Lluch et al) Test product reduced subjective appetite compared to the control (all ratings, P < 0.05) -16% reduction in combined appetite score. Energy intake reduced by 274 kj (6%) after the test compared to control (P < 0.001)

9 Additive effects are hard to achieve and ingredients can unexpectedly block each other s activities PILOT timings and dose combinations Increasing fibre (top left) and increasing protein (top right) increased fullness. At the highest dose of fibre (20g/l), all doses of protein (10g/l, 15 g/l and 21g/l) appeared to decrease fullness.

10 Pre-study evening asked to keep intake and activity similar and consume no alcohol Snacks T3 VAS T4 VAS T5 VAS T8 VAS T9 VAS T10 VAS T1 VAS T2 VAS T6 VAS T7 VAS T11 VAS T12 VAS Combining fibres + RS = HI-MIAZE + Hydrocolloid Guar Gum Protocol Summary Diagram Food and activity diaries satiation satiety satiation satiety satiation satiation A B C End of Day Questionnaire Control Low fibre Meal Meal 0h High fibre 1h 2h 3h 5h 6h 7h 4h 8h Fixed load bagel breakfast Ad lib pizza lunch Ad lib cottage pie dinner Ad lib 5 items 21% greater in kcal for males 289 v 352 kcal (smoothie 381g v 465g) 25% more served to males 25% more served to males Any time during evening

11 Figure 1. Effect of condition on food intake at the ad libitum test meals. Values are mean for 90 participants. 20g; 30g. * P < control; Combining fibres + RS = HI-MIAZE + Hydrocolloid Guar Gum Figure 2. Visual analogue scale (VAS) ratings for (i) hunger and (ii) overall appetite score. Values are presented as changes from baseline score and are means for 90 participants. = 30g, = 20g, = control. * P < g vs control; P < g vs control. B = Breakfast, L = Lunch, D = Dinner

12 These effects were mediated by pre-meal reductions in hunger Harrold et al Prunes used as a snack twice a day (compared to control) significantly reduced daily energy intake but largely via the evening meal. The effect even occur when equal mass (lower energy) portions were used

13 The effect of chronic prune use on appetite and relationship to weight management (Harrold et al. 2014) Weight loss between groups diverged during the last 4 weeks (weeks 8-12), with a trend for greater weight loss in the prune group (0.8 kg v 0.2 kg, p = 0.07). Enduring effects on appetite were observed with AUC analysis of subjective ratings demonstrating increased fullness in the intervention group after week 8 (p = 0.05).

14 WP5: Demonstrate the long-term consumer and health benefits of adhering to a diet containing satiety enhancing products Double blinded parallel randomised multicentre study 10 week LCD for 8.0% weight loss - 8 dietician supervised group meetings 1 week Run in with ad libitum weight maintenance/stabilisation diet 24 week RCT - Ad libitum healthy diet including 10% study products (active or control) for weight loss maintenance - 7 study visits incl. baseline and end of study - 5 individual dietician consultations - Appetite probe days (baseline, midway, end) 7-10d run-in 10w LCD 24w maintenance diet (Active or placebo products) Screening Group meetings Study visits

15 Acknowledgements, Collaborators and Funding Human Ingestive Behaviour Laboratory Dr Joanne Harrold (academic team lead) Mrs Georgina Hughes (researcher) Dr Emma Boyland (academic) Dr Leanne Breslin (researcher) Dr Rory McGill (researcher) Ms Jennifer Walsh (researcher) Dr Simon Child (researcher) Mrs Nicola Williams (laboratory supervisor) Dr Sonia Tucci (academic) Dr Matt Field (associate academic) Professor Tim Kirkham (academic) Professor John Blundell (honorary academic) Dr Graham Finlayson (honorary academic) Dr Andrej Stancak (associate academic) Ms Catherine Slevin (PhD Student) Ms Vassiliki Sinopoulou (PhD Student) Ms Sophia Komninou (PhD Student) The laboratory has received support from: Coca-Cola California Prune Board BBSRC-Case Danone EU Frame Work 7 GlaxoSmithKline Goldshield Lipid Nutrition Kellogg s Kemin Health Care Medical Research Council / NPRI National Starch Natures Remedies NovoNordisk Nutraveris Sanofi Prosidion OSI Weight Watchers