Study Reveals How Eating Olive Oil Before Carbohydrates Affects Blood Sugar - Video

The order in which foods are consumed may influence blood sugar levels, with new research in mice suggesting that eating fat before carbohydrates could help reduce post-meal glucose spikes. The findings, published in Diabetes, highlight how digestive hormones and nerve signals work together to regulate blood sugar.

Researchers from an international team, including scientists at Kyoto University, investigated how the timing of fat consumption affected glucose regulation in mice. The animals were divided into three groups. One received water followed by glucose, another received olive oil 15 minutes before glucose, and the third consumed glucose before receiving olive oil. Researchers measured blood glucose levels, hormones involved in glucose regulation, and gastric emptying, which determines how quickly food moves from the stomach into the small intestine. Additional experiments examined mice with Type 2 diabetes and animals with disrupted hormone signalling.

The findings showed that mice consuming olive oil before glucose experienced a smaller initial rise in blood sugar than those receiving fat afterward. Eating fat first also slowed gastric emptying and stimulated hormones, including glucagon, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), which are involved in glucose regulation. Interestingly, the beneficial effect was also observed in mice with Type 2 diabetes and severe insulin deficiency, suggesting that the response may persist even when insulin regulation is impaired. Researchers found that blocking glucagon or GLP-1 signalling individually did not eliminate the effect.

However, blocking both pathways reduced the benefit, suggesting that these hormones work together. Experiments involving the vagus nerve, which connects the brain and digestive system, further indicated that nerve signalling contributes to this response.

However, the experiments were conducted in mice. Further human clinical studies are necessary to establish whether eating fat before carbohydrates can provide similar benefits in people with or without diabetes.

REFERENCE: Yanyan Liu, et al.; Olive Oil Before Oral Glucose Delays Gastric Emptying and Lowers Glycemia Through Partially Redundant Glucagon and GLP-1 Signaling in Mice. Diabetes, 2026; DOI: 10.2337/db26-0531