Role of familiarity on effects of caffeine- and glucose-containing soft drinks.

Familiarity, through conditioned responses and expectations, may play a significant role in the expression of liking for, and mood and performance effects of, food and drink constituents. The role of familiarity and the effects of caffeine and glucose in Lucozade Energy were investigated by testing this familiar soft drink, and its non-caffeine/non-CHO placebo match, against novel coloured/flavoured full and placebo drinks. Both the familiar drink and its placebo improved alertness, mental energy and mental performance compared to baseline and compared to the novel placebo drink.