Taking control of what foods they eat not only helps people manage their diabetes but also influences how well they feel and how much energy they have every day.

We take a look at what foods people with diabetes should avoid and outline what they should eat instead.

Foods to avoid with diabetes

Having diabetes does not have to stop people from eating the foods they enjoy. However, it does mean that they should eat smaller portions, less often.

The Institute of Medicine recommend that carbohydrate intake for most people should be between 45-65 percent of total calories. This higher carbohydrate intake is consistent with plant-based diets, which have shown benefit for diabetes management in well-designed, long-term studies.

However, some research has shown that people can improve their blood sugar levels when their carbohydrate intake is between 5-35 percent of calories. Much of the research comes from short-term studies for higher-fat diets, such as the ketogenic diet and Mediterranean diets.

Experts are just beginning to understand the influence that the gut bacteria have on health. What is known is that high-fiber carbohydrates feed gut bacteria while a high-fat, low-carb diet often results in gut bacteria death. This is far from ideal as people with diabetes already have lower levels of gut bacteria.

Populations around the world that live the longest, known as Blue Zones, all eat a plant-based diet, rich in whole foods and carbohydrates.

The key to eating well with diabetes is to eat a variety of healthful foods from each of the food groups.

Foods to avoid within the major food groups and suggested replacements are listed below.

Grains

All grains are starches. Avoiding refined grains is a smart choice for people with diabetes, regardless of chosen diet, as they affect blood glucose more quickly than whole grains.

People with diabetes should look at the ingredients list on foods and avoid anything made from white flour, or enriched flour.

Grains and products made from refined flours to avoid or limit:

• white rice, pasta, and flour
• white bread, bagels, white-flour tortillas
• cereals not made from whole grains
• crackers and pretzels
• cookies
• cakes
• muffins

Two extra servings a day of whole grains may reduce the chances of developing prediabetes and has been shown to decrease the risk of developing type 2 diabetes by 21 percent.

Grains to eat:

• brown and wild rice
• barley
• quinoa
• oatmeal
• amaranth
• millet
• high-fiber cereals (at least 5 grams (g) of fiber per serving)
• whole-grain sprouted bread (at least 3 g fiber per serving)

Protein

Protein helps the body build, maintain, and replace the body's tissue. The body's organs, muscles, and immune system are made up of protein. Protein can also be broken down into sugar, although less efficiently than carbohydrates.

Eating red meat, such as beef, pork, and lamb, has been shown to increase the risk of diabetes, even when consumed in small amounts.

One 3-ounce serving of unprocessed red meat, such as beef, per day was found by one review to increase the risk of developing type 2 diabetes by 20 percent. A smaller serving of processed red meat, such as bacon, increased the risk of diabetes by 51 percent.

Swapping red meat or processed red meat for other protein sources that are more healthful, such as poultry, fish, low-fat dairy, whole grains or nuts, may cut the risk of diabetes by up to 35 percent.

Protein to avoid or limit:

• red meat (beef, pork, lamb)
• breaded, fried, high-sodium meats
• processed meats (bacon, hot dogs, deli meats)
• ribs and other fatty cuts of meat
• poultry with skin
• deep-fried fish

Protein to eat:

• beans
• lentils
• nuts
• soy
• fish
• seafood
• poultry without skin
• eggs

Dairy

Dairy proteins are a major source of calcium and contain proteins and vitamins, and people with diabetes can still consume products, such as milk, yogurt, and cheese, every day.

People with diabetes are more likely to develop cardiovascular disease than other people. So, they should exchange foods that increase the levels of cholesterol in the blood and lead to a greater risk of heart disease for lower-fat options.

Dairy to avoid or limit:

• whole milk
• full-fat yogurt
• full-fat cottage cheese
• full-fat cheeses
• full-fat sour cream
• full-fat ice cream

Dairy to eat:

• reduced-fat or fat-free dairy products
• 1 percent or skim milk
• low-fat plain yogurt
• low-fat cottage cheese
• low-fat sour cream

Fruits and vegetables

Fruits and vegetables not only add nutrients to the diet, but they also help manage body weight and reduce the risk of stroke, heart disease, some cancers, and other chronic diseases.

While some fruits may cause blood sugar levels to rise, they do not cause such sharp increases as some carbohydrates, such as bread, do. Whole fruits are considered to be high-quality carbohydrates and contain fiber that may help slow down the absorption of glucose.

Dried fruit contains concentrated natural sugars, which may spike blood glucose levels. People with high blood pressure should also be wary of sodium levels in canned and pickled vegetables.

Fruits and vegetables to avoid or limit:

• dried fruit
• canned fruits with sugar syrup
• regular jam, jelly, and preserves
• sweetened applesauce
• fruit drinks, fruit juice drinks
• canned vegetables with added sodium
• pickles
• sauerkraut

Fruits and vegetables to eat:

• raw, steamed, roasted, or grilled fresh vegetables
• frozen vegetables
• canned vegetables unsalted or low sodium
• fresh fruit
• frozen fruit - no added sugar
• canned fruit - no added sugar
• applesauce - no added sugar

Fats and sugars

Fat is a source of essential fatty acids, such as omega-3, and is an important part of a healthful, balanced diet. Fat also helps the body to absorb vitamins A, D, and E.

Replacing saturated fats and trans fats with unsaturated fats lowers cholesterol and reduces the risk of heart disease.

Sugary foods, sweets, and desserts are made mostly of sugar and are considered to be low-quality carbohydrates. They lack in nutritional value and can cause a sharp spike in blood sugar.

Sugar can also contribute to weight gain, which can make it harder to control diabetes and increase the risk of heart disease and stroke.

Fats and sugars to avoid or limit:

• butter
• lard
• certain oils, such as palm oil
• cream-based dressings or dips
• full-fat mayonnaise
• french fries
• breaded and battered foods
• potato chips
• doughnuts
• croissants
• breakfast pastries
• cakes and cookies
• processed baked goods
• pizza dough
• sauces and condiments
• microwave meals
• table sugar
• agave nectar
• maple syrup
• desserts and candy bars
• fruit-flavored yogurt
• soda
• sweetened ice tea and lemonade
• flavored coffee drinks
• chocolate drinks
• beer
• alcoholic fruit drinks
• dessert wines

Healthful fats and sugar substitutes to eat and drink:

• olive or canola oils
• reduced-fat dressings or dips
• salmon and other fatty fish
• avocado
• nuts
• seeds
• apples
• oranges
• pears
• berries
• bananas
• unflavored water or sparkling water
• no-sugar flavored water
• small amounts of wine
• coffee taken black or with low-fat milk
• fresh, frozen, or dried fruit as a sweetener

Diabetes and carbohydrates

There are three main types of carbohydrates in food, including starches, sugars, and fiber. Carbohydrates affect blood glucose levels more than other nutrients.

The body breaks down starches and sugars into glucose. Fiber, however, is not processed by the body in the same way as other carbohydrates and so does not raise blood sugar levels.

Fruits, vegetables, legumes, and whole grains are considered to be healthful carbohydrates. Healthful carbohydrates provide energy, nutrients, such as vitamins and minerals, and fiber.

While unhealthful carbohydrates, such as food and drinks with added sugars, also provide energy, they contain little nutrients.

People with diabetes need to monitor their intake of carbohydrates to ensure their glucose levels remain within target.

A diabetes educator or dietitian can help with developing a healthful eating plan. They can recommend what foods to eat, how much to eat, and when to eat based on factors like weight, physical activity level, medicines, and blood glucose targets.