Work

The relative efficacy of sensory modalities in driving insulin release, salivary secretion, appetite, and food intake: A systematic review and meta-analysis

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: BACKGROUND: Food sensory stimulation may influence eating behavior, but the effects of different stimulation patterns have not been systematically compared. OBJECTIVE: To quantify the effects of food sensory stimulation on insulin release, salivary secretion, appetite, and food intake, and compare the efficacy of those sensory modalities. METHODS: We systematically searched five databases (PubMed, Web of Science, Cochrane Library, CINAHL, and Embase) for controlled human studies comparing visual, olfactory, gustatory, tactile, modified sham-feeding, or multisensory stimulation. Studies without an eligible comparator or relevant outcome were excluded. RCTs and non-RCTs were synthesized separately using random-effects meta-analysis when compatible numerical data were available and otherwise summarized qualitatively. RESULTS: We included 22 reports comprising 24 studies (6 RCTs, 18 non-RCTs) and 1008 adults (413 men, 595 women). Participants were predominantly healthy; two cohorts were women with obesity. The oldest cohort had a mean age of 72.4 years. RCTs showed increased salivary secretion (SMD=1.04, 95% CI [0.64, 1.45], P<0.0001) but no clear overall effect on food intake (SMD=0.32, 95% CI [-0.25, 0.88], P=0.2742). Insulin release and appetite were each assessed in one RCT and synthesized narratively. Non-RCTs indicated increases in insulin release (SMD=0.95, 95% CI [0.24, 1.66], P=0.0088), salivary secretion (SMD=0.78, 95% CI [0.38, 1.18], P=0.0002), appetite (SMD=0.54, 95% CI [0.29, 0.79], P<0.0001), and food intake (SMD=0.19, 95% CI [0.02, 0.35], P=0.0282). CONCLUSION: RCT evidence suggests that food sensory stimulation increases salivary secretion but has uncertain effect on food intake. Non-RCT evidence indicates potential benefits across all four outcomes, although evidence for insulin release and appetite is limited. Further well-designed RCTs are needed to confirm these effects and clarify differences between sensory modalities.

Source: The journal of nutrition health & aging

DOI: 10.1016/j.jnha.2026.101011