Consumer preference not only dictates what food is consumed but how that food is produced. Ingredients in livestock feed that are not antibiotics, not genetically modified, not of animal origin, and that are nutrient-like, tend to be more acceptable to consumers, retailers, and producers. Mono- and diglycerides (MDG) fit these criteria, are commonly used in food, and are generally recognized as safe. But beyond being emulsifiers and a source of energy, MDG are also known to have antimicrobial, immune and microbiome modulation, and angiogenic activity. MDG in broiler diets have been shown to impact a variety of immune-related functions such as regulation of circulating antibodies, as well as decreased gene expression or protein concentration of pro-inflammatory cytokines like TNF-α, IL-1β, IL-6, and IFN-γ. In addition, MDG can affect metabolic function and intestinal integrity. Results of this review show that MDG can serve as antimicrobial and growth-supporting alternatives for reducing poultry production losses, improving resource utilization, and meeting consumer demand for sustainably produced and safe animal protein.