Acute glycemic and insulinemic effects of low-energy sweeteners: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: It has been suggested that low-energy sweeteners (LES) may be associated with an increased risk of metabolic diseases, possibly due to stimulation of glucose-responsive mechanisms. OBJECTIVE: We conducted a systematic review and meta-analysis of human intervention studies examining the acute effect of LES intake on postprandial glucose (PPG) and postprandial insulin (PPI) responses, in order to comprehensively and objectively quantify these relations. METHODS: We systematically searched the Medline, OVID FSTA, and SCOPUS databases until January 2020. Randomized controlled trials comparing acute postprandial effects on PPG and/or PPI after exposure to LES, either alone, with a meal, or with other nutrient-containing preloads to the same intervention without LES were eligible for inclusion. PPG and PPI responses were calculated as mean incremental area under the curve divided by time. Meta-analyses were performed using random effects models with inverse variance weighing. RESULTS: Twenty-six papers (34 PPG trials and 29 PPI trials) were included. There were no reports of statistically significant differences in the effects of LES on PPG and PPI responses compared with control interventions. Pooled effects of LES intake on the mean change difference in PPG and PPI were -0.02 mmol/L (95% CI: -0.09, 0.05) and -2.39 pmol/L (95% CI: -11.83, 7.05), respectively. The results did not appreciably differ by the type or dose of LES consumed, cointervention type, or fasting glucose and insulin levels. Among patients with type 2 diabetes, the mean change difference indicated a smaller PPG response after exposure to LES compared with the control (-0.3 mmol/L; 95% CI: -0.53, -0.07). CONCLUSIONS: Ingestion of LES, administered alone or in combination with a nutrient-containing preload, has no acute effects on the mean change in postprandial glycemic or insulinemic responses compared with a control intervention. Apart from a small beneficial effect on PPG (-0.3 mmol/L) in studies enrolling patients with type 2 diabetes, the effects did not differ by type or dose of LES, or fasting glucose or insulin levels. This review and meta-analysis was registered at PROSPERO as CRD42018099608

Diacylglycerols affect substrate oxidation and appetite in humans

Diacylglycerols affect substrate oxidation and appetite in humans. Kamphuis MM, Mela DJ, Westerterp-Plantenga MS. Department of Human Biology, Maastricht University, Maastricht, Netherlands. [email protected] BACKGROUND: Meals rich in diacylglycerols (DGs) instead of triacylglycerols (TGs) show beneficial effects on lipid metabolism and energy balance. These effects are probably attributable to differences in DG and TG metabolism, especially postprandial fat oxidation. OBJECTIVE: We assessed the effects of partial replacement of TGs with DGs on substrate oxidation, energy expenditure (EE), relevant blood variables, and appetite. DESIGN: Twelve healthy, dietarily unrestrained women participated in a single-blind, placebo-controlled, randomized trial with crossover design. For 3 d before and throughout a 36-h stay in a respiration chamber, subjects were fed energy-maintenance amounts of a diet consisting of 55% of energy from carbohydrate, 15% from protein, and 30% from fat. In the respiration chamber, 40% of the fat was consumed as DG-rich (80% DGs) oil or as TG-based control oil with a similar fatty acid profile. RESULTS: Fat oxidation was significantly higher with DG treatment than with TG treatment. Appetite profiles during day 1 (24 h) did not differ significantly between the DG and TG treatments; however, feelings of hunger, appetite, estimated prospective food intake, and desire to eat were all significantly lower on day 2 (12 h) with DG treatment. Mean plasma beta-hydroxybutyrate tended to be higher with DG treatment, and the difference between the 2 treatments was significant at 1130 on day 2. Plasma lipid concentrations and resting and 24-h EE did not differ significantly between the 2 treatments. CONCLUSION: Consumption of DGs in place of TGs does not alter EE but produces metabolic effects, particularly increases in fat oxidation, which may be associated with improved appetite control and energy balanc

Effects of learned flavour cues on short-term regulation of food intake in a realistic setting

The present study examined the effects of repeated midmorning consumption of novel-flavoured low- and high-energy yoghurt drinks on subsequent energy intake at lunch in 69 adults under actual use conditions. Subjects consumed 200 ml of low- and high-energy yoghurt drinks (67 and 273 kcal/200 ml, respectively), with 20 exposures to each drink on alternate days. Analyses focused on the development of compensation for the differences in energy content of the beverages, due to learned satiety. Results revealed incomplete energy compensation for the beverages, both at first exposure and also after 20 exposures. Relative to the no-yoghurt condition, energy intake compensation (mean±S.E.M.) averaged 39±36 or the low-energy yoghurt and 17±9 or the high-energy version, with no evidence of any change in compensation with repeated exposures. When the flavours of the yoghurt drinks were covertly switched after 20 exposures, subjects increased their energy intake after the high-energy yoghurt drink containing the flavour that was previously coupled with the low-energy yoghurt drink. Vice versa, however, when subjects switched to the low-energy yoghurt drink containing the high-energy flavour, subjects ignored the flavour cue and ate the same lunch size regardless of the energy in the yoghurt drink. We conclude that adults do not readily acquire accurate conditioned adjustments for the energy content in food after repeated experience with the food in free-living natural-eating conditions

Short- and long-term effects of changes in pleasantness on food intake

This study concerns the effects of pleasantness on ad libitum food intake, liking and appetite over 5 successive days. Pleasantness was manipulated by varying the salt level in bread. Thirty-five students consumed ad libitum sandwiches for lunch, made with bread individually perceived as low, medium or high in pleasantness, in a balanced cross-over design. Pleasantness and desire-to-eat the sandwich were rated at first bite, after the consumption of each sandwich and at the end of the lunch. Fullness was rated just before and at several intervals after lunch. On the first day, the students ate less of the least pleasant bread than of the medium and most pleasant bread. On the fifth day, however, consumption of all breads was similar. For the least pleasant bread, energy intake at lunch, desire-to-eat and fullness, all increased over days, whereas these variables remained constant for the medium and most pleasant bread. Mean pleasantness ratings for all breads remained unaltered across the days. We conclude that, with repeated exposure, the desire-to-eat, fullness and intake of a less preferred food can increase over time. Thus, the relationship between pleasantness and food intake changes over this period