Satiety Innovation- Study 793. University of Aberdeen

Previous research has suggested that food structure and food composition has a role to play in controlling consumption. Low-energy, high-fibre diets provide physical bulk in the gastro-intestinal tract to sustain fullness in a way that low-volume, energy-dense foods cannot. However, studies shown low long term acceptability be probably associated to its poor palatability. Taste and hedonic experience remain the main drivers of consumer choice, and the immediate sensory aspect of food products such as palatability to have greater salience to consumers than their health promoting properties.

Changing the properties of foods merely by changing oro-sensory properties and through the delay of gastric emptying deals with mechanisms critical to within-meal satiation and early post meal satiety and may produce only transient suppression of hunger unless regularly consumed and represent benefits in delivering nutritional stimuli to key parts of the gastro-intestinal tract. The potential to manufacture change can make food structure variety now seem near limitless due the numerous advances in food technology.

Several recent reports have associated satiety effects with fermentable fibre sources in human dietary studies (Nillson et al., 2008, Parnell & Weimer, 2009, Willis et al 2009). Apparently, the large intestine microbiota recovers 'extra' calories from the diet and might contributes to obesity (Ley et al., 2006, Turnbaugh et al., 2008, Cani et al., 2007). However, the different mechanisms involved in lean and obese subjects are not completely resolved (Duncan et al., 2008, Schwiertz et al., 2010). Recent evidence in experimental animal designs indicates that changes in gut microbiota composition may be associated with increased food intake and obesity (Vijay-Kumar et al., 2010) suggesting that satiety and intake are influenced by the species composition of the gut microbiota.

The proposed study will address the effect of developed novel food products through processing innovation on motivation to eat, biomarkers of satiety, nutrient bioavailability and gut health using in vivo studies and validating new in vivo approaches. Specifically in this protocol we will address the effect of a potentially satiating product on appetite, appetite biomarkers, particularly the influence on gut microbiota, tolerance and safety of the products in healthy obese and overweight volunteers in free living conditions. This study is part of the major European project launched in early 2011: SATIN, a collaborative, large-scale project that brings together the expertise of 18 participants across Europe to develop food products through novel food process that enhance satiety.

This short-term human nutrition study comprises in a cross-over design testing either a potentially satiety product, resistant starch type 3 (RS3) or an equivalent amount heterogeneous natural fibre in 24 healthy- obese volunteers, aged 18-65 years old, Body Mass Index (BMI) between 27 and 35kg/m2 from both genders after an initial 21 day weight-loss programme, in free- living conditions. Dietary intake, body weight, blood pressure would be monitored through the study. Faecal, urine and blood samples will be collected to monitor, glucose, insulin, gut peptides and assess metabolites of dietary and microbial origin. Gut transit will be monitored in six volunteers using a wireless motility device (SmartPill™)

Inclusion criteria

• Males and females
• 18-65 years old
• Body Mass Index (BMI) 27-35kg/m2
• Overall healthy
• Weight Stable (<3 kg change in the past 4 months, before the trial).

Exclusion criteria

• Medical:
• Heavy smokers (more than 10 cigarettes/day) or heavy alcohol consumers (more than 4 alcohol units/day for male and more than 3 alcohol units/day for female).
• Obesity of endocrine origin.
• Chronic metabolic conditions: diabetes, hepatic disease, gout, kidney, thyroid or coagulation disease.
• Gastrointestinal disorders: celiac disease, ulcerative colitis, irritable bowel syndrome (IBS), Chron's disease, chronic constipation, diverticulitis, history of gastric bezoar. Suspected strictures, fistulas, or physiological GI obstruction.
• Psychiatric disorder: severe depression, bulimia, anorexia, schizophrenia, bipolar disorder.
• Gastrointestinal procedure or surgery in the past three months.
• Disorders of swallowing, severe dysphagia to food or pills.
• Pregnancy

Medication exclusion criteria

• Appetite modulator drugs: orlistat, sibutramine, rimonabant.
• Mood disorder medications: antidepressants, lithium.
• Others: oral antidiabetics, insulin, digoxin, thyroid hormones, antibiotics, steroids or immunosuppressants, recreational substances.
• Use of implanted or portable electro-mechanical device such as cardiac peacemaker or infusion pump.
• Blood donor in the past 3 months.