Visual food cues decrease blood glucose and glucoregulatory hormones following an oral glucose tolerance test in normal-weight and obese men

Think Yourself Slim? Assessing the Satiation Efficacy of Imagined Eating

Ubiquitous exposure to visual food content has been implicated in the development of obesity with both individual and societal costs. The development and increasing adoption of Extended Reality (XR) experiences, which deliver an unprecedented immersion in digital content, would seem to carry the risk of further exacerbating the consequences of visual food exposure on real-world eating behavior. However, some studies have also identified potentially health-promoting effects of exposure to visual food stimuli. One example is repeated imagined consumption, which has been demonstrated to decrease subsequent food consumption. This work contains the first comparison between imagined eating and actual eating, to investigate how the simulated activity fares against its real counterpart in terms of inducing satiation. Three-hundred participants took part in an experiment at a local food festival. The participants were randomized between three experimental conditions: imagined eating, actual eating, and control. Each condition consisted of thirty trials. Before and after the experimental manipulation, the participants recorded their eating desires and enjoyment of a piece of chocolate candy. The resulting data showed generally no difference between the imagined eating and control conditions, which stands in conflict with the prior literature. In contrast, the differences between imagined and actual eating were significant. These results may be explained by differences in the experimental tasks' dose-response relationships, as well as environmental-contextual disturbances. Overall, the findings do not corroborate the efficacy of imagined eating within a real-life context.

The cephalic phase of insulin release is modulated by IL-1β

The initial cephalic phase of insulin secretion is mediated through the vagus nerve and is not due to glycemic stimulation of pancreatic β cells. Recently, IL-1β was shown to stimulate postprandial insulin secretion. Here, we describe that this incretin-like effect of IL-1β involves neuronal transmission. Furthermore, we found that cephalic phase insulin release was mediated by IL-1β originating from microglia. Moreover, IL-1β activated the vagus nerve to induce insulin secretion and regulated the activity of the hypothalamus in response to cephalic stimulation. Notably, cephalic phase insulin release was impaired in obesity, in both mice and humans, and in mice, this was due to dysregulated IL-1β signaling. Our findings attribute a regulatory role to IL-1β in the integration of nutrient-derived sensory information, subsequent neuronally mediated insulin secretion, and the dysregulation of autonomic cephalic phase responses in obesity.

Exercise improves bone formation by upregulating the Wnt3a/β-catenin signalling pathway in type 2 diabetic mice

BACKGROUND

The bone formation ability of type 2 diabetes is inhibited, and exercise can effectively improve the bone formation of T2DM. However, whether exercise can mediate the Wnt3a/β-catenin pathway to improve the mechanism of bone formation and metabolism still needs further research.

METHODS

A T2DM mouse model was established by a high-fat diet and STZ injection, and the mice were trained with swimming and downhill running exercise. Alizarin red staining is used to observe the changes of the left femoral trabecular bone; micro-CT is used to analyze the trabecular and cortical BMD, BV/TV, BS/BV, BS/TV, Tb.Th, Tb.Sp; the ALP staining of skull was used to observe the changes in ALP activity of bone tissues at the skull herringbone sutures; ALP staining was performed to observe the changes in the number of OBs and ALP activity produced by differentiation; Quantitative PCR was used to detect mRNA expression; Western blot was used to detect protein expression levels.

RESULTS

When the Wnt3a/β-catenin pathway in the bones of T2DM mice was inhibited, the bone formation ability of the mice was significantly reduced, resulting in the degradation of the bone tissue morphology and structure. Swimming caused the significant increase in body weight and Runx2 mRNA expression, while downhill running could significantly decrease the body weight of the mice, while the tibia length, wet weight, and the trabecular morphological structure of the distal femur and the indexes of bone histomorphology were significantly improved by activating the Wnt3a/β-catenin pathway.

CONCLUSIONS

Bone formation is inhibited in T2DM mice, leading to osteoporosis. Downhill running activates the Wnt3a/β-catenin pathway in the bones of T2DM mice, promotes OB differentiation and osteogenic capacity, enhances bone formation metabolism, and improves the bone morphological structure.