Olive Oil Before Carbs Lowered Blood Sugar Spikes in Mice, Study Finds

Two groups of mice received the same amount of olive oil and the same amount of glucose. Only one group had a smaller blood sugar spike, and the difference was which one came first. The response behind it was not what you’d expect, since it involved glucagon, a hormone known for raising blood sugar, along with a nerve that links the brain and the gut. This was a mouse study, so it isn’t a recommendation yet. But it points to a change in how you eat, not what you eat, and it may explain why the order of a meal can change what happens in your body afterward. Here is what the researchers found and what you can take from it today.

Why the Order of Your Meal Affects Your Blood Sugar

Most of us think about blood sugar in terms of what’s on the plate: rice, bread, pasta, sweets. Carbohydrates break down into glucose, so that focus makes sense. But the order in which you eat your food matters too.

This is relevant because keeping blood sugar from climbing too high after a meal is a central part of diabetes management. And it’s often the hardest part to get right.

Meal sequencing is an emerging dietary approach for diabetes and obesity. Earlier clinical studies show that eating vegetables, protein, or fat before carbohydrates keeps blood sugar lower afterward. You eat the same food in a different order, and the rise is smaller.

Researchers have proposed two explanations:

1. Slower gastric emptying. Food leaves the stomach more gradually, so glucose reaches the small intestine later and enters the bloodstream more slowly.
2. Greater incretin release. Incretins are gut hormones that help regulate blood sugar, and GLP-1 is the best known. It boosts insulin and suppresses appetite, and drugs like Ozempic mimic it.

What scientists haven’t fully understood is how the gut, the pancreas, and the nervous system coordinate this response. A team led by endocrinologist Daisuke Yabe at Kyoto University set out to answer that, using olive oil as the fat.

Yabe also points out the practical appeal: meal sequencing changes only how a meal is eaten. Nobody has to cut out a whole food group, which makes it easier to keep up long term.

Olive Oil Before Carbs Lowered Blood Sugar and Slowed the Stomach

The researchers fasted mice overnight and split them into three groups:

1. Water, then glucose: the control group.
2. Olive oil, then glucose 15 minutes later: fat first.
3. Glucose, then olive oil 15 minutes later: fat second.

To see how fast the stomach was emptying, they also gave the mice acetaminophen. The more of the drug that shows up in the blood, the faster the stomach is passing its contents along.

The mice that got olive oil first had significantly lower blood glucose right after the meal. The reductions were most marked at 15 and 30 minutes compared with the other groups. By 60 minutes, the difference had faded. Their stomachs also emptied more slowly, so glucose moved into the intestine later.

The timing mattered. Olive oil given after glucose did not produce the same benefit, which tells us the order itself drives the effect.

It also worked in mice with type 2 diabetes. In diabetic models with severely reduced insulin production, olive oil still lowered the blood sugar rise and slowed gastric emptying. For people with diabetes, this is the most relevant finding. It suggests the response doesn’t depend on a fully working insulin system.

Not all fats performed equally. The team also tested flaxseed oil, lard, coconut oil, and fish oil. Olive oil generally did best at controlling blood sugar. Flaxseed oil and lard produced similar results on some measures.

So the timing of the fat, and to some degree the type of fat, shaped the outcome. The next question is what’s happening inside the body to produce it.

How Olive Oil Slows the Stomach

When the mice ate olive oil before glucose, three hormones rose early: glucagon, GIP, and GLP-1. GIP and GLP-1 are incretins, which help regulate glucose after eating. Glucagon was the surprise.

Glucagon raises blood sugar. It signals the liver to release stored glucose, so you’d expect it to work against the effect. Yet blocking glucagon signaling on its own did not cancel the benefit of olive oil. Blocking GLP-1 signaling on its own didn’t either.

Blocking both at once did. The drop in blood sugar weakened or disappeared, and the slowing of gastric emptying vanished. The two pathways are partly redundant: either one can carry the response, but the body needs at least one of them. So glucagon, despite its reputation, can contribute to limiting the glucose rise when fat arrives first.

The vagus nerve is also involved. This nerve carries signals between the brain and the digestive system, helping coordinate digestion and hormone release. When the researchers surgically interrupted vagus nerve signaling, olive oil’s ability to blunt the blood sugar rise and slow gastric emptying weakened or became undetectable. The hormone responses stayed intact. Hormones alone, then, don’t explain the result.

The authors describe an integrated hormone-and-nerve response rather than the work of one hormone.

Why the order matters is still a hypothesis. If glucose is absorbed first, the rapid rise in blood sugar may dampen the pancreatic alpha cells, the cells that release glucagon, so they respond poorly to fatty acids. If olive oil comes first, fatty acid sensing switches on before blood glucose climbs.

Should You Eat Olive Oil Before Carbs?

This was a mouse study. That’s the main limit, and it shapes everything else here. The researchers themselves state that these effects haven’t been established in humans, and we have no human data yet on how much olive oil, how long before a meal, or in which people. Clinical studies are needed to find out whether the same mechanisms work in people with or without diabetes.

What we can say with more confidence is that meal order is a reasonable thing to try. Earlier human studies already link eating vegetables, protein, or fat before carbohydrates to lower blood sugar. The new work adds a biological explanation for why fat first may help: slower gastric emptying, driven by glucagon, GLP-1, and the vagus nerve working together.

What to do with this:

• Start the meal with the non-carbohydrate foods. Vegetables, protein, or a fat source such as olive oil on a salad can go first, with the rice, bread, or pasta after.
• Keep your portions in mind. Olive oil is calorie-dense, and the study doesn’t tell us how much is useful for a person.
• Don’t change your diabetes treatment on your own. If you take medication or insulin, meal sequencing is something to discuss with your doctor, not a replacement for your plan.

The appeal is simple. You don’t have to give up the foods you eat. You change the order they arrive in.

Olive oil is also an easy ingredient for researchers to test in human trials. The results of those trials will tell us whether this works in practice.

My Personal RX on Building a Blood Sugar-Friendly Plate

The mouse findings are early, but meal order is something you can test at your own table. How you build a meal can change how your body handles the carbohydrates in it, and small habits repeated daily add up. Here are my personal tips.

1. Start With Vegetables or Protein: Eat non-starchy vegetables or a protein source first, then the rice, bread, or pasta. Human studies already link this order to lower blood sugar after meals.
2. Drizzle Olive Oil on Your First Course: A little olive oil on a salad or vegetables puts fat at the start of the meal. Keep portions modest, since it is calorie-dense.
3. Pause Before the Carbs: Finish the first course, then give it a few minutes before moving on. Eating slowly also helps you notice fullness.
4. Choose Fiber-Rich Carbohydrates: Beans, lentils, and whole grains digest more slowly than refined starches and fit well with this approach.
5. Support Your Digestion: Stomach emptying is central to this research, so digestion matters. My Digestive Enzymes help break down food and ease bloating after heavier meals.
6. Walk for 10 Minutes After Eating: Your muscles use glucose for fuel, so light movement after a meal helps bring blood sugar down.
7. Build Steady Energy: My Weight Loss Bundle pairs MetaBurn, Protein Plus, and Magnesium Essentials to support metabolism, reduce cravings, and keep energy steady between meals.
8. Protect Your Sleep: Poor sleep makes blood sugar harder to regulate. Aim for a consistent bedtime and a full night’s rest.
9. Check How You Respond: If you have diabetes, ask your doctor before changing how you eat. Your glucose readings will show whether meal order works for you.
10. Learn the Gut Connection: My book Heal Your Gut, Save Your Brain explains how digestion, hormones, and the nervous system work together.

Sources:

1. Eating olive oil before carbs has a surprising effect on blood sugar. (2026). ScienceDaily. https://www.sciencedaily.com/releases/2026/10/261008102700.htm
2. Liu, Y., Tsuchida, H., Kubota, S., Kubota-Okamoto, S., Kato, T., Horikawa, Y., Tsunekawa, S., Kuwata, H., Fujiwara, Y., Yamazaki, Y., Yamada, Y., Fujita, H., Iizuka, K., Murao, N., Ueno, S., Seino, Y., Suzuki, A., Hayashi, Y., Nakanishi, T., … Yabe, D. (2026). Olive oil before oral glucose delays gastric emptying and lowers glycemia through partially redundant glucagon and GLP-1 signaling in mice. Diabetes, db260531. https://doi.org/10.2337/db26-0531