Can You Eat Oats and Oatmeal If You Have Diabetes?

Written by Helen West, RD (UK) on February 4, 2017

Oatmeal is a healthy breakfast choice and a great way to start your day.

It's low in calories and full of fiber, which can make it the perfect food for people who are trying to control their weight.

However, oatmeal also contains a lot of carbs. For this reason, people with diabetes may wonder if it's a good choice for them.

This article takes a closer look at oatmeal and explores whether it's a healthy choice for people with diabetes. The answer may surprise you.

Oatmeal, sometimes called porridge, is a food made with oat groats. These are oat kernels that have had their hard outer husks removed.

There are three main types of oatmeal, including steel-cut, whole (also called rolled) and instant oatmeal. They differ in the way they're processed, as steel-cut oats are cut rather than rolled like whole and instant varieties.

Most people eat their oatmeal hot. They make it by mixing their oats with either boiling water or milk. You can also reduce prep time by making oatmeal without heat, soaking it in milk or water overnight and eating it cold in the morning.

However you prepare it, oatmeal is a good source of carbs and fiber, particularly soluble fiber. It also contains a range of vitamins and minerals.

For most people, it's a balanced and highly nutritious food choice. 100 grams (3.5 ounces) of dry oats provides the following nutrients ():

  • Calories: 389
  • Carbs: 66 grams
  • Protein: 17 grams
  • Fiber: 11 grams
  • Fat: 7 grams
  • Manganese: 246% of the RDI
  • Phosphorus: 52% of the RDI
  • Vitamin B1 (thiamine): 51% of the RDI
  • Magnesium: 44% of the RDI
  • Copper: 31% of the RDI
  • Iron: 26% of the RDI
  • Zinc: 26% of the RDI
  • Folate: 14% of the RDI
  • Vitamin B5 (pantothenic acid): 13% of the RDI

As you can see, oats are low in calories and high in nutrients.

However, they also contain a lot of carbs. And if you make your oatmeal with milk, this will increase its carb content even more.

For example, each 1/2 cup of whole milk you add to your oats will add around 13 grams of carbs and 73 calories ().

Summary: Oats are a highly nutritious food high in carbs, fiber and some vitamins and minerals.

Oatmeal contains a lot of carbs. In fact, carbs make up 67% of the calories in oats ().

This can be a concern for people with diabetes, since carbs cause blood sugar levels to rise.

Normally, the body responds to sugar in the blood by releasing the hormone insulin.

Insulin works by telling your body to take the sugar out of your blood and into your cells, where it can be used for energy or stored.

However, people with diabetes don't produce enough insulin, or they have cells that don't respond to insulin in the normal way. When these people eat too many carbs, their blood sugar may rise to unhealthy levels.

That's why it's important for people with diabetes to minimize these large spikes in blood sugar and maintain good blood sugar control.

Good blood sugar control helps reduce the risk of diabetes complications like heart disease, nerve damage and eye damage ().

Summary: Oats are high in carbs. This is a concern for people with diabetes, since carbs cause blood sugar levels to rise.

Oats may be high in carbs, but they are also high in fiber, which can have beneficial effects on blood sugar control.

Fiber helps slow down the rate at which carbs are absorbed into the blood ().

When you're assessing which carbs are better for keeping your blood sugar under control, you'll want to look for types that are absorbed more slowly.

A great tool for this is the glycemic index (GI) scale.

The scale scores a food based on how quickly it raises blood sugar levels, and classifies it as low, medium or high on the GI scale:

  • Low GI: Score of 55 or less
  • Medium GI: Score of 56–69
  • High GI: Score of 70–100

Carbs with a low GI, which are absorbed more slowly, are thought to be beneficial for people with diabetes. This is because they provide beneficial nutrients without spiking your blood sugar like more quickly absorbed carbs can (, , , , ).

Porridge made with rolled or steel-cut oats is classed as a low-to-medium GI food, since both these types of oatmeal have a GI score between 50 and 58 (, , ).

However, it's important to note that different types of oats are not created equal.

Instant oats have a slightly higher GI, at around 65, which means their carbs are absorbed more quickly and are more likely to cause blood sugar spikes ().

Summary: The high fiber content of oatmeal means the carbs it contains are slowly absorbed and less likely to cause large blood sugar spikes.

Some studies have shown that eating oats may improve blood sugar control.

In a review of 14 studies, eating oats was found to lower fasting blood sugar by 7 mg/dL (0.39 mmol/L) and HbA1c by 0.42% in type 2 diabetics ().

It's thought that this occurs because they contain beta-glucan, a type of soluble fiber (, ).

This type of fiber absorbs water in your gut and forms a thick, gel-like paste ().

Some studies have shown that this can help slow down the rate at which your body digests and absorbs carbs, resulting in better blood sugar control (, , ).

A recent review found that the beta-glucan from oats can reduce fasting blood sugar and improve blood sugar control in people with type 2 diabetes. It reduced fasting blood sugar by 9.36 mg/dL (0.52 mmol/L) and HbA1c by 0.21%, on average ().

Some small studies have also linked eating foods containing beta-glucan with decreased insulin resistance in people with type 2 diabetes (, ).

However, the results are mixed. Other studies have found oatmeal to have no effect on insulin resistance (, ).

Overall, studies investigating how oats affect people with type 2 diabetes have found that they improve blood sugar control and insulin response (, , ).

However, the effects of oats on people with type 1 diabetes have not been studied as much.

Summary: Oats may be helpful for lowering blood sugar levels and improving blood sugar control in people who have type 2 diabetes.

Eating oatmeal may also provide you with other health benefits.

Improved Blood Lipids

Some studies have linked eating oats with lower levels of total cholesterol and "bad" LDL cholesterol. On average, this amounts to a modest reduction of around 9-11 mg/dL (0.25-0.30 mmol/L) (, , ).

Researchers have attributed this effect to the high levels of beta-glucans in oats. These are thought to help lower your body's cholesterol levels in two ways.

First, they're thought to slow down digestion and reduce the amount of fat and cholesterol you absorb from your gut ().

Second, beta-glucans are known to bind to the cholesterol-rich bile acids in your bowel. This prevents your body from reabsorbing and recycling them, so they pass out of your body in your stool (, , ).

Since high cholesterol levels are associated with an increased risk of heart disease, including oats in your diet may help lower your risk (, , , , ).

Improved Weight Management

Oats are thought to be a good food to eat if you are trying to lose weight. One of the reasons for this is that they can help fill you up.

This makes them a potentially useful food if you are trying to manage your weight and prevent yourself from overeating.

It's thought that the filling effect of oats is partly due to the high levels of beta-glucans they contain.

Because beta-glucans are a soluble fiber, they form a thick gel in your gut. This helps slow the rate at which food leaves your stomach, and helps you feel fuller for longer (, , , ).

Additionally, oatmeal is low in calories and rich in nutrients. This makes it a great choice for people who are trying to lose weight and improve their health ().

Improved Gut Health

Oats are high in prebiotic soluble fiber, so oatmeal is thought to have the potential to improve the balance of the good bacteria in your gut (, ).

In fact, one small study has suggested that oatmeal can directly change the balance of your gut bacteria ().

However, larger studies are needed to support these findings and discover if this change is linked to any health benefits.

Summary: Eating oatmeal could provide you with other health benefits. These include improved blood lipids and weight management.

Oatmeal is a healthy food that many people with diabetes can include in their diets.

Plain rolled or steel-cut oats are the best option because they have the lowest GI and no added sugar.

However, there are a few factors you should consider if you have diabetes and are considering adding oatmeal your diet.

First of all, watch your portion size. Although oatmeal has a low GI, eating very large portions can increase what's known as the glycemic load (GL).

GL is an estimate of how much a certain portion of a particular food will raise your blood sugar levels after you eat it ().

For example, a normal portion is around one cup of cooked oatmeal (250 grams). This has a GL of 9, which is low ().

However, if you double your portion size, the GL will also double.

Additionally, although GI and GL can be good guidelines, it's important to note that blood sugar responses to carbs can be very individual. This means it's important to monitor your blood sugar and note how you respond ().

Also be aware that if you control your diabetes with a low-carb diet, then oatmeal is not a suitable food choice, since it is very high in carbs.

Summary: Oats can have several benefits for people with type 2 diabetes, but they are not a good choice on a low-carb diet. Make sure to watch your portions and monitor your blood sugar levels.

Oats are a healthy food packed full of beneficial nutrients. They can be included in the diets of people with diabetes.

However, it's important to remember that, at the end of the day, they're still carbs.

This means that if you have diabetes, mind your portion sizes and be aware that oats may not be suitable if you manage your diabetes with a low-carb diet.

An evidence-based nutrition article from our experts at Authority Nutrition.

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