Modulation of sweet preference by the actual and anticipated consequences of eating

Further evidence for sensitivity to energy density and a two-component model of meal size: Analysis of meal calorie intakes in Argentina and Malaysia

Previously, we demonstrated a non-linear association between meal caloric intake and meal energy density (ED, kcal/g) in data from a controlled trial in the US and from free-living participants in the UK [1]. In both datasets, meal caloric intake increased with ED in lower energy-dense meals (below ∼1.75 kcal/g) and decreased in higher energy-dense meals (above ∼1.75 kcal/g). In the current study, we sought to explore whether this pattern extends to data from free-living participants in Argentina (N = 2738 meals) and Malaysia (N = 4658 meals). Again, a significant breakpoint was found in both the Argentinean (2.04 kcal/g (SE = 0.06)) and Malaysian (2.17 kcal/g (SE = 0.06)) datasets with mean centered meal caloric intake increasing with ED below the breakpoint and decreasing above the breakpoint. These results lend further support for our two-component theoretical model of meal size (g) in which a volume signal is dominant in lower energy-dense meals and a calorie-content signal is dominant in higher energy-dense meals. Together, our research adds to evidence supporting human sensitivity to calories and exposes a complexity in the correspondence between meal energy content and meal size in everyday (non-manipulated) meals. Further research is needed to provide causal evidence for this sensitivity and whether individual variation impacts meal size and energy balance.

Determinants of Sweetness Preference: A Scoping Review of Human Studies

Factors associated with sweetness preference are multi-faceted and incredibly complex. A scoping review was undertaken to identify determinants of sweetness preference in humans. Using an online search tool, ProQuest ™, a total of 99 publications were identified and subsequently grouped into the following categories of determinants: Age, dietary factors, reproductive hormonal factors, body weight status, heritable, weight loss, sound, personality, ethnicity and lifestyle, previous exposure, disease, and 'other' determinants. Methodologies amongst studies were heterogenous in nature (e.g., there was variability across studies in the sweetness concentrations tested, the number of different sweetness concentrations used to assess sweetness preference, and the methods utilized to measure sweetness preference), rendering interpretation of overall findings challenging; however, for certain determinants, the evidence appeared to support predictive capacity of greater sweetness preference, such as age during certain life-stages (i.e., young and old), being in a hungry versus satiated state, and heritable factors (e.g., similar sweetness preferences amongst family members). Recommendations for the design of future studies on sweetness preference determinants are provided herein, including an "investigator checklist" of criteria to consider.

Sweet satiation: Acute effects of consumption of sweet drinks on appetite for and intake of sweet and non-sweet foods

Sensory-specific satiety (SSS) describes a reduction in the pleasantness of the taste of (momentary liking) and desire to consume a food that occurs with eating, compared with the relative preservation of liking and desire for uneaten foods. We conducted three studies in healthy female and male participants to test whether SSS generalises from sweet drinks to sweet foods. Studies 1 (n = 40) and 2 (n = 64) used a two-condition cross-over design. Participants consumed non-carbonated, fruit squash drinks sweetened with low-calorie sweeteners (LCS) versus water and evaluated various food and drink samples (stimuli). Generalisation of SSS was evident across all sweet stimuli, without having an effect on non-sweet (savoury) stimuli. These SSS effects were present when measured shortly after consumption of the sweet drink, but not 2 h later. There was no evidence of a 'rebound' increase above baseline in liking or desire to consume sweet foods 2 h after the sweet drink versus water. In study 3, 51 participants consumed labelled and branded 500 ml cola and water drinks (4 conditions, cross-over design) immediately before and during ad libitum consumption of sweet and non-sweet snack foods. Compared with still water, 'diet' (LCS-sweetened) cola reduced sweet food intake, but not total ad libitum intake. Carbonated water decreased hunger and increased fullness compared with still water, without differentially affecting thirst. Energy compensation from the ad libitum snacks for consumption of sugar-containing cola averaged only 20%. Together, these results demonstrate that consumption of LCS drinks acutely decreases desire for sweet foods, which supports their use in place of sugar-sweetened drinks. Further studies on the effects of carbonation of appetite are warranted.