Caffeine in sugar-sweetened beverages: A silent amplifier of preference and intake

Sugar-sweetened beverages remain a major source of dietary sugar exposure, yet the behavioural contribution of caffeine within these products is often treated as secondary to sweetness, branding and convenience. This commentary argues that caffeine in cola-style sugar-sweetened beverages is better understood as a behavioural and nutritional amplifier than as a benign flavour adjunct. Although caffeine is a bitter tastant in water, psychophysical evidence indicates that caffeine at commercial concentrations is largely imperceptible within cola matrices because sweetness, acidity, carbonation and flavour complexity mask low-intensity bitterness. Its post-ingestive effects may nevertheless reinforce learned preference, support habitual intake and contribute to higher voluntary consumption. Product level evidence also suggests that caffeine-containing variants can carry slightly higher sugar concentrations than their caffeine-free counterparts. Integrating sensory science, flavour-nutrient learning, caffeine pharmacology and consumer behaviour provides a more complete account of how caffeine may silently increase sugar exposure. This framing has implications for formulation, labelling, dietary guidance and future research on beverage choice.