Caffeine reinforces flavor preference and behavior in moderate users but not in low caffeine users

Problematic internet users' skin conductance and anxiety increase after exposure to the internet

INTRODUCTION

To examine the impact of cessation of an internet session on skin conductance responses and anxiety of higher and lower problem internet users, in order to explore possible physiological withdrawal effects.

METHOD

Participants were measured in terms of their skin conductance before (15min), during (15min), and after (15min) an internet session, and completed self-report measures of state anxiety and problematic internet use.

RESULTS

Higher, but not lower, problem users showed increased skin conductance after internet use was stopped, relative to before their internet session. Higher problem users' GSR scores increased, as the time from internet cessation became longer. Higher problem users also showed increased levels of anxiety, following their internet session, which correlated with their skin conductance scores.

CONCLUSIONS

These results suggest that, following termination of an internet session, withdrawal-like effects are seen, both psychologically and physiologically.

Caffeine increases liking and consumption of novel-flavored yogurt

RATIONALE

Caffeine has been shown to increase preference for beverages with which it is paired; however, it is not known if caffeine alters liking for foods with which it is paired indirectly.

OBJECTIVES

The purpose of the current experiment was to test the hypothesis that a caffeinated beverage paired with a novel-flavored yogurt will increase preference for that yogurt compared to one paired with placebo. We also tested the hypothesis that liking would increase more when caffeine was paired with high energy density yogurt.

METHODS

Men and women (n = 62) were randomized to receive a beverage containing placebo (PLA) or caffeine (CAF) and to consume a low (LED) or high energy density (HED), novel-flavored yogurt. Participants rated, ranked, and consumed seven novel-flavored yogurts and then had a target yogurt paired with either PLA or CAF over four consecutive days.

RESULTS

In general, yogurt liking increased over time, the HED yogurt was liked more than the LED yogurt, and yogurt paired with caffeine was liked more than yogurt paired with placebo. Participants showed a significant increase in liking of LED yogurt paired with caffeine compared to those with LED yogurt paired with placebo.

CONCLUSIONS

Caffeine administration may increase liking and consumption of novel-flavored foods, particularly if the food is not highly liked at baseline. This suggests that caffeine pairing may be a way to increase liking of LED foods, such as vegetables and fruit.