Consuming fat before carbohydrates reduces post-meal blood glucose (opens in a new tab)

In plain English

Genetic loss-of-function test in Gcg-deficient mice: the olive-oil preload (OG)–associated reduction in early postchallenge glycemia and slowing of gastric emptying was reported as absent in Gcg-deficient mice (abstract).

Key findings

• The olive oil preload–associated reduction in early postchallenge glycemia and slowing of gastric emptying was absent in Gcg-deficient mice (abstract).

In plain English

Genetic loss-of-function test: Glp1r-deficient mice underwent the olive-oil preload (OG) before an oral glucose challenge. According to the abstract, the OG-associated early reduction in postchallenge glycemia and slowing of gastric emptying were largely preserved in Glp1r-deficient mice, indicating that GLP-1 receptor signaling alone is not required for the preload effect and suggesting redundancy with glucagon signaling.

Key findings

• In Glp1r-deficient mice, the olive oil preload largely preserved the early reduction in postchallenge blood glucose and slowing of gastric emptying (as reported in the abstract).

In plain English

In mice receiving an olive-oil preload before oral glucose, pharmacologic blockade of glucagon and/or GLP-1 receptors was used to test whether these receptors are required or act redundantly to mediate the preload's effects on early postchallenge glycemia and gastric emptying. Blockade of either receptor alone largely preserved the glycemia-lowering and gastric-emptying–slowing responses, whereas combined blockade attenuated the glucose-lowering effect and eliminated detectable gastric slowing, consistent with partially redundant signaling by glucagon and GLP-1 pathways.

Key findings

• Pharmacologic blockade of either the glucagon receptor or the GLP-1 receptor alone largely preserved the olive-oil preload–induced lowering of early postchallenge glycemia and slowing of gastric emptying.
• Combined pharmacologic blockade of both glucagon and GLP-1 receptors attenuated the glucose-lowering effect of the olive-oil preload and eliminated detectable slowing of gastric emptying, supporting partially redundant signaling by these pathways.

In plain English

The authors report that the olive-oil preload (OG) effect — reduced early postchallenge glycemia and slowed gastric emptying observed in non-diabetic mice — was also evident in streptozotocin (STZ)-induced diabetic mice. The abstract states similar accompanying increases in glucagon, GIP, and GLP-1 secretion and preserved gastric slowing and glycemia lowering in diabetic animals, but provides no quantitative details in the abstract.

Key findings

• In streptozotocin (STZ)-induced diabetic mice, an olive-oil preload reduced the early postchallenge blood glucose excursion and slowed gastric emptying; authors report similar hormone secretion changes as in non-diabetic mice.

In plain English

The paper reports that olive-oil preload (OG) was tested in diabetic mouse models including NSY mice. In the diabetic cohorts the authors state that OG produced effects similar to those seen in wild-type mice: reduced early post‑oral‑glucose glycemia, slowed gastric emptying, and increased secretion of glucagon, GIP, and GLP‑1. The abstract does not provide numerical effect sizes, sample sizes, or per‑model breakdown, so it is unclear which specific measurements (glycemia time course, gastric emptying, individual hormone assays) were performed in NSY mice versus other diabetic models.

Key findings

• Olive oil preload reduced the early post‑oral‑glucose blood glucose excursion in diabetic mice (abstract statement: 'Similar effects were evident in diabetic mice').
• Olive oil preload slowed gastric emptying in diabetic mice (reported as similar to effects in WT mice).

In plain English

In mice subjected to bilateral subdiaphragmatic vagus nerve ligation (VNL), the olive‑oil preload’s ability to slow gastric emptying and reduce the early post‑oral‑glucose glycemic excursion was attenuated, despite preserved or enhanced circulating incretin and glucagon secretion, supporting a contribution of vagal signaling to the preload effect.

Key findings

• Bilateral subdiaphragmatic vagus nerve ligation attenuated the olive oil preload–induced slowing of gastric emptying and reduction of early postchallenge glycemia, even though circulating glucagon and incretin (GLP‑1, GIP) responses were preserved or enhanced.