Caffeine increases sugar-sweetened beverage consumption in a free-living population: a randomised controlled trial
Excessive sugar-sweetened beverage (SSB) consumption has been associated with overweight and obesity. Caffeine is a common additive to SSB, and through dependence effects, it has the potential to promote the consumption of caffeine-containing foods. The objective of the present study was to assess the influence that caffeine has on the consumption of SSB. Participants (n99) were blindly assigned to either a caffeinated SSB (C-SSB) or a non-caffeinated SSB (NC-SSB) group. Following randomisation, all participants completed a 9 d flavour-conditioning paradigm. They then completed a 28 dad libitumintake intervention where they consumed as much or as little of C-SSB or NC-SSB as desired. The amount consumed (ml) was recorded daily, 4 d diet diaries were collected and liking of SSB was assessed at the start and end of the intervention. Participants (n50) consuming the C-SSB had a daily SSB intake of 419 (sd298) ml (785 (sd559) kJ/d) over the 28 d intervention, significantly more than participants (n49) consuming the NC-SSB (273 (sd278) ml/d, 512 (sd521) kJ/d) (P< 0·001). A trained flavour panel (n30) found no difference in flavour between the C-SSB and NC-SSB (P>0·05). However, participants who consumed the C-SSB liked the SSB more than those who consumed the NC-SSB (6·3v.6·0 on a nine-point hedonic scale,P= 0·022). The addition of low concentrations of caffeine to the SSB significantly increases the consumption of the SSB. Regulating caffeine as a food additive may be an effective strategy to decrease the consumption of nutrient-poor high-energy foods and beverages.