Diet plays an important role in managing type 2 diabetes. Your blood sugar reacts to foods in different ways, depending on what you eat and how much of it you consume at mealtime.

Here’s what you need to know about serving sizes and portions when you have type 2 diabetes.

Portions and serving sizes both relate to the quantity of food at a meal. But there are some key differences to understand.

The term “portion” describes how much food you decide to eat for a snack or at mealtime. You choose the amount that’s in a portion. For example, a handful of almonds, a glass of milk, or a blueberry muffin can all be considered a portion.

Since there’s no objective measurements of a portion, it can be tricky to figure out how many calories, carbs, and fiber are in a given amount of food.

Understanding roughly what’s in an average portion of food, such as a medium-sized sweet potato, can help you estimate how many carbs you’re consuming.

Serving size, on the other hand, is an objective quantity of food or drink. This is typically measured by a cup, ounce, or other unit, such as a single slice of bread. This allows people to more accurately measure the amount of calories, sugar, protein, and nutrients in a given food.

Nutrition labels on food packages list the serving size for that item. You’ll want to look at how many serving sizes are in the container, too.

For example, a blueberry muffin that you buy at a convenience store may actually be considered two serving sizes. That means the number of calories, carbs, and other components listed on the label will be doubled if you eat the whole muffin.

When you have type 2 diabetes, it’s important to pay attention to the amount of carbs, protein, and fiber you consume at each snack and meal.

Fiber can help keep blood sugar levels balanced. The Mayo Clinic recommends that people with type 2 diabetes seek out foods with at least 3 grams of fiber per serving.

Adding protein to meals and snacks can help improve blood sugar control and increase feelings of fullness. This may be particularly helpful for people with diabetes who have excess weight to lose.

Being mindful about the amount of food you eat can help you avoid high blood sugar levels. Here are a few portion control strategies for people with type 2 diabetes.

Counting carbs

Limiting the amount of carbs you eat can help keep your blood sugar within target range. It’s especially important to limit refined carb sources, such as white bread, sugary baked goods, and sweetened beverages.

Talk to your doctor to learn how many carbs you should be eating at mealtimes and in total for the day.

Then keep track of your carb intake using a notebook, a notes app on your phone, or another tracking tool.

The Centers for Disease Control and Prevention (CDC) offers a list of carb counts and serving sizes for everyday foods, such as breads, beans, fruits, and vegetables. This can help you tally up your carb intake.

The plate method

Your plate can provide a visual tool for eating the right proportions of foods.

Half of your plate should be filled with non-starchy vegetables, such as leafy greens, broccoli, or zucchini.

The remaining half of your plate should be evenly divided between lean proteins, such as tofu or chicken, and grains or starches, such as potatoes or brown rice. Or, you could skip the starches and give yourself a double portion of non-starchy vegetables instead.

You can also add a serving of fruit on the side, such as a small pear.

To help manage your blood sugar, it’s best to drink beverages that are low in calories and carbohydrates, such as water or unsweetened tea.

The “plate method” may help you eat a balanced diet and limit your chances of accidentally overeating carb-rich foods that might spike your blood sugar.

Measure with your hand

Do you carry a food scale around with you? If not, you can use the next best thing to measure portions when you’re eating out: your hand.

Your fist is roughly the size of a cup or a medium-size piece of fruit, such as an apple.

When it comes to lean protein, the palm of your hand (without the fingers) equates to about 3 ounces of meat, seafood, or poultry.

An ounce of cheese or meat is around the length of your thumb.

You can estimate a cupped handful of nuts or chips to be about 1 to 2 ounces.

And if you’re trying to measure fats, such as butter or avocado, the tip of your thumb is about a tablespoon, while the tip of your index finger is a teaspoon.

Although this method isn’t quite as accurate as using a measuring cup or a scale, your hand can help you eat appropriate portion sizes and keep your blood sugar levels in a normal range.

Proper nutrition and portion control can play an important role in the treatment of type 2 diabetes.

Your doctor can offer individualized guidance on what you should be eating, including the amount of certain food groups that you should consume. Using serving size strategies can help you stick to those guidelines.

Eating a nutritious and well-rounded diet, managing serving sizes, and getting regular physical activity can help you maintain healthy blood sugar levels. It can also support weight loss and weight maintenance — and promote good overall health and wellness.

Eating a nutritious diet and keeping your portion sizes in check is important for managing type 2 diabetes.

Strategies such as carb counting, the plate method, and measuring portions with your hand can help you avoid eating too many carbohydrates and calories. This can help you control your weight and blood sugar levels.

Talk to your doctor about what and how much you should eat on a daily basis to manage type 2 diabetes.