Butter is a common ingredient used in cooking and baking. It adds richness, moisture, and flavor to foods. However, there are some concerns that butter may raise blood sugar levels. In this article, we’ll take a closer look at the evidence on butter and its effects on blood sugar.
What is butter?
Butter is a dairy product made by churning cream. It is high in fat, containing at least 80% fat by weight. The main types of fat in butter are saturated fat and monounsaturated fat. It also contains cholesterol and small amounts of protein, carbohydrates, vitamins, and minerals (1).
The two main types of butter are:
- Salted butter: Contains added salt, extending its shelf life.
- Unsalted butter: Does not contain added salt.
Butter can be used in both savory and sweet recipes, such as baked goods, sauces, soups, vegetables, and more. Its high fat content makes it an excellent conductor of heat and gives baked goods a tender texture.
Does butter contain carbs and sugar?
Butter is very low in carbs and sugar.
One tablespoon (14 grams) of butter contains (2):
- Total carbs: 0.1 grams
- Sugars: 0 grams
The trace amounts of carbs in butter come from milk solids like lactose. However, the amount of carbs and sugar is negligible.
This means that butter itself does not directly raise blood sugar levels. However, it’s important to consider how butter is used and what it’s paired with, as these factors can influence its effects on blood sugar.
How does fat affect blood sugar?
Eating fat alone has a negligible effect on blood sugar levels. However, high-fat foods can indirectly affect blood sugar when consumed with carbs (3).
Here’s how fat influences blood sugar control:
- Slows digestion of carbs. Fat can slow down the digestion and absorption of carbohydrates. This results in a more gradual rise in blood sugar over a longer time, compared to carbs alone.
- Triggers insulin release. Fat triggers the release of insulin, the hormone that lowers blood sugar. Higher fat meals require more insulin to be released to handle the additional calories.
- Increases insulin resistance. Diets high in saturated and trans fats are linked to increased insulin resistance over time. This makes it harder for cells to respond to insulin’s signals.
In moderation, the effects of fat on blood sugar are usually negligible in healthy people. Issues mainly arise when large amounts of fats are consumed regularly.
Does butter raise blood sugar directly?
On its own, butter is unlikely to raise your blood sugar or insulin levels. However, it can indirectly affect blood sugar when consumed in large amounts.
Studies on blood sugar response to high-fat meals have found:
- In one study in 12 healthy people, eating 75 grams of butter on its own did not change blood sugar or insulin levels (4).
- Another study compared the effects of an avocado-butter mix versus olive oil in 16 healthy adults. The avocado-butter blend resulted in higher insulin levels, but minimal changes in blood sugar (5).
- Research in 156 adults found that meals containing saturated fats led to higher insulin demand compared to meals high in monounsaturated or polyunsaturated fats (6).
Overall, moderate intake of butter alone has negligible effects on blood sugar in healthy people. High intakes may increase insulin response, but not blood sugar levels.
Blood Sugar Effects of Butter When Paired With Carbs
Butter becomes more of a concern for blood sugar when consumed with carbohydrate-rich foods.
Some studies have found:
- One study compared white bread eaten with butter, olive oil, or nothing added. The butter meal caused significantly higher blood sugar and insulin levels compared to olive oil and no fat (7).
- In another study, reducing the amount of fat in a high carb meal decreased insulin response by 15-25% (8).
The blood sugar effects seem most pronounced when butter is consumed with high glycemic index carbs like white bread, potatoes, white rice, and sweets.
Overall, butter can spike blood sugar and insulin when consumed with large portions of carbs, especially refined carbs high in sugar.
Why does combining carbs and butter raise blood sugar?
Here are some reasons why the combination of carbs and butter can drive up blood sugar levels:
- Slowed digestion of carbs — Fats can slow down stomach emptying and the digestion of carbohydrates, resulting in a steadier rise in blood sugar (9).
- Increased carb absorption — Butter is high in saturated fat. Saturated fat has been found to increase the absorption of carbohydrates from the digestive tract (10).
- Decreased insulin sensitivity — High saturated fat intake can reduce insulin sensitivity over time, making it harder for your body to lower blood sugar in response to carbohydrate intake (11).
- Altered gut hormones — Fats may influence hormones released from the gut that impact insulin secretion and glucose metabolism, though findings are mixed (12).
In summary, butter’s effects on digestion, carb absorption, insulin sensitivity, and gut hormones likely contribute to its blood sugar raising effects when paired with carbs.
Does butter’s fat content matter?
Butter is high in saturated and monounsaturated fats.
Interestingly, different types of fats can have unique effects on blood sugar. The saturated and monounsaturated fat content of butter may matter:
- Saturated fat — Has been found in several studies to increase insulin resistance when consumed in excess, especially when paired with high carb foods (13).
- Monounsaturated fat — Mainly found in plant oils like olive and avocado oil. Monounsaturated fats lower blood sugar and improve insulin sensitivity when they replace saturated fats (14).
This suggests the high saturated fat content of butter could be more problematic for blood sugar control than monounsaturated-rich fats when consumed alongside carbs.
Grass-fed vs Regular Butter
Grass-fed butter may also have an advantage when it comes to blood sugar.
One study compared the effects of regular butter and grass-fed butter on blood sugar for 6 hours after a meal. Grass-fed butter led to lower blood sugar and insulin levels (15).
The higher vitamin K2 levels in grass-fed butter could be one factor improving its effects on blood sugar regulation (16).
Overall, grass-fed butter may be a better option if you are concerned about the blood sugar effects of butter. But more studies are needed comparing grass-fed and regular butter.
How much butter is safe per day?
There is no universal safe upper limit for butter or total fat intake. The amount considered acceptable depends on your total calorie needs and health status.
However, most major health organizations recommend limiting saturated fat to less than 10% of total calories (17, 18).
The American Heart Association suggests even lower limits of about 6% of calories, especially for those at high risk of heart disease (19).
To keep saturated fat within recommended ranges, here are some suggested daily limits based on different calorie levels:
| Daily Calories | Daily Saturated Fat Limit (grams) | Tablespoons of Butter* |
|---|---|---|
| 1,200 | 13 | 1.5 |
| 1,500 | 17 | 2 |
| 1,800 | 20 | 2.5 |
| 2,000 | 22 | 2.5 |
| 2,500 | 28 | 3 |
*Based on 14 grams of saturated fat per tablespoon of butter (2).
Consuming butter within suggested limits should not significantly impact blood sugar for most people, especially if carbs are controlled.
Of course, those with diabetes or prediabetes may need to be more cautious with saturated fat intake, including butter. Consult your healthcare provider for advice tailored to your individual health.
Foods to eat instead of butter
If you are concerned about the saturated fat and potential blood sugar effects of butter, some alternatives include:
- Extra virgin olive oil — Has antioxidant and anti-inflammatory benefits. Lowers blood sugar when substituted for butter (20).
- Avocado oil — High in monounsaturated fats and vitamin E to protect heart health (21).
- Nut butters — Provide plant-based protein and fiber. Look for options with minimal added oil and sugar.
- Hummus — Made from chickpeas. Excellent source of fiber and plant-based protein.
- Tahini — Sesame seed paste. Often used to replace butter in vegan baked goods.
When swapping butter for olive or avocado oil, use about 3/4 of the amount of butter called for in recipes. For spreads like nut butters and tahini, the conversion will depend on the recipe.
Despite common concerns, grass-fed butter can also be a good alternative if you don’t want to fully eliminate butter for blood sugar reasons.
Healthy ways to eat butter
If you want to keep butter in your diet, here are some tips for consuming it in moderation:
- Measure portions instead of scraping butter from a communal stick.
- Use butter in cooking instead of baking. It’s easier to control portions.
- Pair butter with non-starchy veggies, meats, fish, and eggs rather than breads, crackers, and pastries.
- Use sparingly as a spread on bread or toast.
- Add a teaspoon to steamed vegetables for flavor.
- Substitute half the butter in baking recipes with olive or avocado oil.
- Look for organic, grass-fed varieties.
Focusing on whole, minimally processed sources of fat like nuts, seeds, avocados, and olive oil can also help minimize butter intake while providing healthier unsaturated fats.
The bottom line
Butter has minimal direct effects on blood sugar due to its low carb content. However, its high saturated fat content can spike blood sugar levels when consumed in large amounts, especially alongside refined carbohydrates.
Enjoying butter in moderation as part of a healthy diet based on whole foods is unlikely to have major effects on blood sugar for most people. But those with diabetes, prediabetes, or cardiometabolic disease may need to be more mindful of butter and saturated fat intake.
As with any food, it’s important to consider both the type and amount of butter consumed, as well as the overall quality of your diet for optimal blood sugar control and metabolic health.
