Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

BACKGROUND: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. OBJECTIVE: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink) versus nutrient-rich drink (yoghurt drink) on reward value after repeated exposure. DESIGN: We used a randomized crossover design whereby forty subjects (15 men, 25 women) with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2) consumed a fixed portion of a non-caloric sweetened (NS) and sugar sweetened (SS) versions of either a soft drink or a yoghurt drink (counterbalanced) for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18) fMRI was performed to assess brain reward responses to the drinks. RESULTS: Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. CONCLUSION: Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

Sip size of orangeade: effects on intake and sensory-specific satiation.

Sensory-specific satiation (SSS) drives food selection and contributes to meal termination. We hypothesised that smaller sips would increase SSS due to increased oro-sensory exposure, irrespective of energy content. The objective was to determine the effects of sip size and energy content on ad libitum intake of orangeade and subjective SSS for orangeade. Orangeade intake and ratings of wanting and liking were measured before and after ad libitum orangeade consumption in a 2 x 2 cross-over design (n 53). Conditions differed in energy content (no-energy v. regular-energy orangeade) and in sip size (large, 20 g/sip v. small, 5 g/sip). The mean intake of both orangeades was lower when consumed with small sips than when consumed with large sips (regular-energy, 352 v. 493 g; no-energy, 338 v. 405 g; both P < 0.001). When consumed with large sips, the mean intake of no-energy orangeade was lower than that of regular-energy orangeade (P = 0.02). When consumed with small sips, subjective SSS (based on the desire to drink) was higher for no-energy orangeade than for regular-energy orangeade (P = 0.01), while mean intake was comparable. We concluded that smaller sip size, i.e. increased oro-sensory exposure per unit of consumption, can lower intake of sweet drinks. Only with low oro-sensory exposure (large sip size) was intake higher for an energy-containing sweet drink than for a no-energy sweet drink. This suggests that intake of sweet drinks is stimulated by (metabolic) reward value and inhibited by sensory satiation. This underpins the importance of SSS for meal termination.

Discrepancy between snack choice intentions and behavior.

OBJECTIVE: To investigate dietary constructs that affect the discrepancy between intentioned and actual snack choice. DESIGN: Participants indicated their intentioned snack choice from a set of 4 snacks (2 healthful, 2 unhealthful). One week later, they actually chose a snack from the same set. Within 1 week after the actual choice, they completed a questionnaire that evaluated several dietary constructs. SETTING: Worksite cafeterias. PARTICIPANTS: Office employees in the Netherlands (N = 585, 65% male, mean age 39.6 years [standard deviation = 9.2], 83% highly educated). MAIN OUTCOME MEASURES: Snack choice intentions and actual snack choices (healthful vs unhealthful). Demographic and dietary constructs. ANALYSIS: Student t tests, chi-square tests, and logistic regression (P < .05). RESULTS: Forty-nine percent of the participants (n = 285) intended to choose a healthful snack. Of this group, 27% (n = 78) chose an unhealthful snack instead. Ninety-two percent (n = 276) of the unhealthful intenders did indeed choose an unhealthful snack. None of the dietary constructs significantly predicted the failure to enact a healthful snack choice intention. CONCLUSIONS AND IMPLICATIONS: Although a substantial discrepancy between healthful intentions and actual snack choice was demonstrated, the evaluated constructs do not adequately measure the psychological process by which intention is converted into practice. Further studies are required to further investigate this process.