In this chapter, the authors relay available scientific information regarding the role of soy peptides or soy hydrolysates on weight management. Proposed mechanisms include (a) regulation of satiety and food intake; (b) decrease lipid absorption and modulation of lipid metabolism; (c) increased thermogenesis and energy expenditure; and (d) inhibition of adipogenesis. Although there is not enough clinical information to claim a clear benefit of soy peptides on obesity, there is evidence to suggest that some soy peptides may have a future as regulators of adiposity and satiety. These two properties may have an impact on weight management.