Does Olive Oil Raise Blood Sugar? What Happens After a Meal?

Short answer: no. Olive oil is pure fat and contains no carbohydrates, so on its own it does not push blood sugar up. The more interesting question is what olive oil does to the blood sugar rise from the food you eat it with. Three small meal studies have looked at exactly that, and this post explains what they found and what they cannot tell you.

The first, in Diabetes Care, followed 13 adults with type 1 diabetes who ate the same high glycemic meal three times, once with extra virgin olive oil, once with butter, and once with a low-fat version. The second, in the Journal of Clinical Endocrinology and Metabolism, tested six men with type 2 diabetes. The third, in Nutrition and Diabetes, tested 25 healthy adults. These are very small trials that measured a few hours after a single meal, so they show a pattern worth knowing about, not a proven result.

At a Glance: What the After-Meal Studies Show •  Olive oil contains no carbohydrate, so it does not raise blood sugar by itself. •  In 13 adults with type 1 diabetes eating the same high glycemic meal, the blood sugar rise over the first three hours was about half as large with extra virgin olive oil as with butter or a low-fat version. •  In six men with type 2 diabetes, olive oil taken 30 minutes before a carbohydrate meal slowed stomach emptying, delayed the blood sugar rise, and raised the gut hormone GLP-1. •  In 25 healthy adults, a meal with 10 grams of extra virgin olive oil led to a lower blood sugar reading two hours later than the same meal without it. •  All three studies were small and short. None of them is advice for managing diabetes.

Why Olive Oil Does Not Raise Blood Sugar on Its Own

Blood sugar rises when you digest carbohydrates, the starches and sugars in bread, rice, fruit, and sweets. Fat does not break down into glucose in the same way, and olive oil has no carbohydrate in it at all. That is why you will not find a glycemic index number for it. The scale only measures how fast carbohydrate foods raise blood sugar.

That does not mean the oil does not affect a meal. One tablespoon is about 120 calories, and the oil changes what happens to the food around it. Fat slows the stomach down, and a slower stomach changes how quickly sugar from the rest of the meal arrives in the blood. That is the part the studies look at.

What Happens When Olive Oil Meets a Carbohydrate Meal

The clearest picture comes from the six men in the type 2 diabetes study. Each man drank 30 milliliters of olive oil, about two tablespoons, 30 minutes before a meal of mashed potato, which is a fast carbohydrate. On other days, they had water first, or had the oil mixed into the potato. When the oil came first, the stomach emptied far more slowly, the blood sugar rise was delayed and peaked later, and the insulin response was smaller. The gut hormone GLP-1 rose more. GLP-1 is a hormone released after eating that helps tell the pancreas to release insulin and tells the brain you are full.

In plain terms, the oil acted like a speed bump. The sugar from the potato still arrived, just later and more gradually. For a deeper look at GLP-1 and what the research supports and does not, see Does Olive Oil Boost GLP-1? What the Research Actually Shows.

Olive Oil vs Butter in the Same Meal

The type 1 diabetes trial asked a different question. All 13 adults ate the same high glycemic meal, built around fast carbohydrates, and the only change was the fat added to it: about 2.7 tablespoons of extra virgin olive oil, a similar amount of butter, or a low-fat version. Over the first three hours, the blood sugar rise was about half as large with olive oil as with butter or the low-fat meal. The oil did not change the carbohydrate. It changed how the body handled it.

Two cautions apply. People with type 1 diabetes manage their blood sugar with insulin, so the result does not carry over to everyone, and it was only measured for a few hours. And the meal was deliberately high in fast carbohydrate. The study does not show that olive oil lowers blood sugar after every meal. If you are comparing fats more broadly, see Olive Oil vs Butter: Which Is Healthier for Cooking and Baking?.

What Happens in People Without Diabetes

The third study tested 25 healthy adults. On one day, they ate a Mediterranean-style lunch with 10 grams of extra virgin olive oil, about two teaspoons. On another day, they ate the same lunch without it. Two hours after the olive oil meal, their blood sugar was lower, and their insulin and GLP-1 were higher. The researchers also swapped the olive oil for corn oil in the same meal. The olive oil meal came out better on blood sugar and blood fats.

It is a promising result, but a modest one. This was an ordinary lunch, with a small amount of oil, and blood sugar was checked only once, two hours later. At most, it suggests that a little olive oil with a meal may help smooth out the blood sugar rise. It does not show that olive oil protects against diabetes. For that longer question, see The Cooking Oil That Cut Diabetes Risk by 40 Percent in a Major Trial.

What This Does Not Tell You About Diabetes

All three studies checked blood sugar for a few hours after a single meal. None of them followed people for months or tested olive oil as a treatment, so none can say whether olive oil lowers blood sugar over the long run. That is a different question, about fasting glucose and insulin resistance after months of daily use, and it has its own research. For that evidence, see Olive Oil and Diabetes: How EVOO Affects Blood Sugar and Insulin Sensitivity.

If you have diabetes or take medicine that lowers blood sugar, do not change how you eat because of a study this small. Fat slows digestion, which can change when your blood sugar peaks. Talk to your doctor or dietitian before using olive oil as a way to manage meals.

How to Use This at the Table

If you are curious, the practical takeaway is modest. Use olive oil as a regular part of a meal that already includes carbohydrate, such as drizzled over vegetables, beans, grains, or a piece of bread. Keep the amount to about a tablespoon, and count it as part of your meal, not an extra. For a sensible daily amount, see How Much Olive Oil Should You Take Per Day?.

Be careful about taking oil on its own if your goal is steady blood sugar. The studies tested oil with or before a carbohydrate meal, not a spoonful by itself. If you want to try a spoonful before eating, read Olive Oil on an Empty Stomach: Does It Actually Work first. If you want to build olive oil into a daily habit, see A 30-Day Olive Oil Routine: What to Do Each Week. And because every tablespoon adds calories, see Can Olive Oil Help With Weight Management? The Mediterranean Diet Data.

Why Four Hour Olive Oil Is Worth Having on the Table Polyphenols, the plant compounds behind much of olive oil’s flavor and benefit, start fading the moment olives are picked. Much grocery store oil has lost a large share of them before it reaches your shelf. The studies above used extra virgin olive oil, so the oil you pour should be the real thing. Four Hour Olive Oil presses Ayvalik olives within 4 hours of harvest on the Aegean coast of Turkey. It is USDA Organic, single origin, and bottled in Italian dark glass, which makes it a true high-polyphenol olive oil with real flavor. Ultra Premium is made for finishing food and for the raw spoonful. Premium is made for everyday cooking. If you are going to add olive oil to your meals, the oil should actually contain what you are eating it for. Ultra Premium EVOO  |  Premium EVOO  |  Duo

Frequently Asked Questions

Does olive oil raise blood sugar?

Not on its own. Olive oil contains no carbohydrates, so it does not raise blood sugar the way bread or sugar does. In small meal studies, adding it to a carbohydrate meal was linked to a smaller or slower blood sugar rise.

What is the glycemic index of olive oil?

It does not have one. The glycemic index measures how fast carbohydrate foods raise blood sugar, and olive oil has no carbohydrate to measure.

Does olive oil lower blood sugar after a meal?

In three small studies, a meal with olive oil produced a lower or slower blood sugar rise than a comparison meal. The studies had 6, 13, and 25 people and measured only a few hours, so this is early evidence, not proof.

Does olive oil spike insulin?

The results differ by study. In the 25 healthy adults, insulin was higher two hours after the olive oil meal. In the six men with type 2 diabetes, the insulin rise was smaller when the oil came before the meal. Both findings fit with the oil changing how fast the meal is absorbed.

Is olive oil safe for people with diabetes?

Olive oil is a common part of Mediterranean-style eating, but this post is not diabetes advice. If you have diabetes or take medicine that lowers blood sugar, ask your doctor or dietitian how to fit it into your meals.

Does olive oil help with insulin resistance?

These after-meal studies do not answer that. Insulin resistance is a long-term question, covered in our post on olive oil and diabetes.

Should I take olive oil before a meal to lower blood sugar?

One small study of six men with type 2 diabetes used 30 milliliters of olive oil 30 minutes before a meal. That is a research design, not a recommendation, and it adds about 240 calories. Do not use it as a treatment.

Does olive oil slow digestion?

Yes, fat in general slows how fast the stomach empties, and olive oil did so in the type 2 diabetes study. For some people, this can mean feeling full longer, and for others it can mean bloating.

Which olive oil should I use with meals?

Use a fresh, high polyphenol extra virgin olive oil that you enjoy tasting. Four Hour Ultra Premium Extra Virgin Olive Oil is made for finishing food and for raw use. Four Hour Premium Extra Virgin Olive Oil is made for everyday cooking.

Is olive oil better than butter for blood sugar?

In the type 1 diabetes trial, the blood sugar rise over three hours was about half as large with olive oil as with butter in the same high glycemic meal. It was one small study with 13 adults, so treat it as a clue.

How much olive oil is safe to eat with a meal?

The studies used from about two teaspoons to nearly three tablespoons. A tablespoon is about 120 calories, so most people do best using it in place of other fats, not on top of them.

Will olive oil help me lose weight or control hunger?

There is no proof from these studies. Olive oil has calories, and it can help you feel full after a meal, but it is not a weight loss treatment.

References [1] Bozzetto, L., et al. "Extra-virgin olive oil reduces glycemic response to a high-glycemic index meal in patients with type 1 diabetes: a randomized controlled trial." Diabetes Care 39(4): 518-524. 2016. View study [2] Gentilcore, D., et al. "Effects of fat on gastric emptying of and the glycemic, insulin, and incretin responses to a carbohydrate meal in type 2 diabetes." Journal of Clinical Endocrinology and Metabolism 91(6): 2062-2067. 2006. View study [3] Violi, F., et al. "Extra virgin olive oil use is associated with improved post-prandial blood glucose and LDL cholesterol in healthy subjects." Nutrition and Diabetes 5(7): e172. 2015. View study

The studies cited in this post are peer-reviewed and publicly available. This content is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare professional before making changes to your diet or health regimen.