Phone (08) 92662771Key words: hunger, satiety, whey protein, alginate, viscosity. 2 AbstractSatiety is important in regulating food intake and has important public health significance in the control of obesity. Food containing protein and non-starch polysaccharides provides a satiety effect through various mechanisms but a comparison of the satiety effect on each has not previously been investigated. This study compared the satiety effect or reduction of hunger after consumption of (i) a whey protein-based drink versus an alginate-based drink of the same viscosity where only the protein content differed , (ii) two alginate-based drinks differing in alginate type and viscosity, and iii) a whey protein-based drink versus an alginate-based drink differing in protein content and viscosity. Fasted subjects assessed the effect of a drink on hunger that was one of three variants: a low viscosity whey-protein drink (LVHP); a high viscosity low protein alginate-based drink (HVLP); or a low viscosity low protein alginate-based drink (LVLP) over the 240 minutes postprandial period using a Visual Analogue Scale (VAS). When protein differed and viscosity was the same, resultsshowed subjects felt significantly less hungry after consuming the LVHP drink compared to the LVLP drink, so protein reduced hunger. Subjects reported reduced hunger from the HVLP drink compared to the LVLP drink where viscosity of drinks differed, suggesting viscosity and/or gelation reduced hunger. Subjects reported reduced hunger from the HVLP drink compared to LVHP drink where both protein and viscosity differed, suggesting that viscosity reduced hunger more than the protein effect. Results suggest the physical characteristics such as viscosity and/or gel strength and protein content reduce hunger.Further studies should investigate which of these parameters is more important.3