Type 2 diabetes is caused by many factors, and what you eat is one of the things that you can most control. Some foods seem OK at first glance, but they contain hidden sugar or excess saturated fats that can lead to health problems. Avoiding these foods can improve your overall health and help you lower your risk of diabetes and other diseases associated with diabetes.

While no single food directly causes type 2 diabetes, this article discusses foods to limit to help improve your overall health and decrease your risk of developing type 2 diabetes.

People with diabetes should avoid these foods

Starchy vegetables

Vegetables are typically recommended as part of a healthy diet. However, some vegetables contain more carbohydrates than others. These are called starchy vegetables.

If you are trying to decrease your carbohydrate intake, lowering the amount of starchy vegetables you consume can help. Some starchy vegetables include potatoes (all varieties), corn, green peas, and winter squash such as pumpkin, butternut squash, and acorn squash.

Starchy vegetables still contain many beneficial nutrients and can fit into a balanced diet when eaten in moderation. Some starchy vegetables, such as sweet potatoes and butternut squash, contain many vitamins, minerals, and phytonutrients that are beneficial to health.

Using healthier cooking methods such as steaming, baking, or air frying are good ways to still include starchy vegetables without overdoing them. Try to build your meals around non-starchy vegetables and count any starchy vegetables as the carbohydrate foods in your meal. Aim to include a variety of different-coloured vegetables to get the most nutrients in your diet.

Red and processed meat

Meat does not contain carbohydrates, so you might wonder how it can impact diabetes risk. A large cohort study of over 63,000 Chinese adults suggested that eating red meat can increase the risk for type 2 diabetes. This association seemed to be stronger in women than in men.

The researchers reported that heme iron found within red meats is more readily absorbed compared to the non-heme iron found mainly in plant-based foods and may be partially to blame for this associated risk. Multiple possibilities of why high iron intake may lead to an increased risk of diabetes have been proposed.

One such theory is that iron leads to impaired beta-cell function in the pancreas (the cells that produce insulin, a hormone that allows cells to take in glucose) due to oxidative stress (producing more unstable oxygen molecules than the body’s antioxidants can neutralise).

Another result of the oxidative stress caused by high heme iron intake may be decreased glucose uptake in muscle and adipose (fat) cell sites, leading to insulin resistance. Insulin resistance is a precursor to type 2 diabetes in that the body doesn’t respond to insulin as it should.

However, the full mechanisms by which this risk may occur are not clear, as there are very few studies that investigate this association.

Another theory on why red meat intake is associated with a higher risk of type 2 diabetes has to do with the way the meat is cooked. Studies have shown that meat cooked with high heat to a well-done or charred level may increase the risk of certain chronic diseases, including type 2 diabetes.

Red and processed meats are also known to be high in nitrites and nitrates. These have been shown to lead to increased insulin resistance, abnormal blood glucose (sugar) levels, and increased oxidative stress—all of which can increase the risk of developing type 2 diabetes.

Most research supporting the link between red meat and diabetes has been observational studies, whereas a meta-analysis of randomized controlled trials (a statistical analysis of studies in which participants are randomly put into experimental vs control groups) hasn’t found the same association.

Processed fruit

Whole fruits are full of vitamins, minerals, fibre, and other good-for-you nutrients. However, the nutritional benefit can change when fruits are processed and altered from their original state.

Fruit processed into the form of jams, jellies, sweetened snacks, or canned fruit packed in heavy syrup typically contains high amounts of added sugars so avoiding these foods might be a good idea for people with diabetes. Dried fruits also sometimes contain added sugar.

High added sugar intake has been associated with an increased risk of metabolic syndrome (a syndrome of high blood pressure, high blood sugar, abnormal levels of cholesterol and fat in the blood, and excess abdominal fat) and type 2 diabetes.

When eating fruit, opt for whole fruits. Other options, such as 100% fruit juice, canned fruit packed in 100% fruit juice or water, and dried fruits with no added sugar, can fit into a balanced diet when consumed in moderation. Consuming whole fruits has actually been shown to decrease the risk of type 2 diabetes.

White Rice

Rice is a staple grain in many diets and regions throughout the world. White rice is a refined grain that has had the bran and germ removed, leaving the starchy endosperm.

As a result of this processing, compared to brown rice, white rice is low in fibre, polyphenols, and other vitamins and minerals. White rice also has a higher glycemic index, meaning it can lead to high blood glucose levels after consumption.

A study of over 132,000 people from 21 countries found that a high intake of white rice was associated with a 20% increased risk of diabetes compared to low rice consumption. The risk varied by region, with South Asia having a 65% higher risk for high vs. low rice consumption and China having no significant association.

The US Department of Agriculture (USDA) recommends making at least half of your daily grain intake whole grains. Brown rice is a great way to get in some of your whole grains. Other whole-grain options include quinoa, barley, farro, or bulgur.

Soda

Soda and other sugar-sweetened beverages have long been studied for their relation to health and chronic disease. Many researchers have studied the link between type 2 diabetes and sugar-sweetened drinks.

Sugar-sweetened beverages include regular soda and drinks such as juice with added sugar, fruit drinks, sports drinks, flavoured coffee beverages, sweetened tea, and energy drinks.

A study examining the association between sugar-sweetened beverages and type 2 diabetes found that drinking sugar-sweetened drinks led to a significantly increased risk of developing type 2 diabetes so its better for people to avoid them.

A prospective cohort study of Mexican adults estimated that each sugar-sweetened beverage serving consumed per day increased type 2 diabetes risk by 18%.

Instead of drinking soda throughout the day, choose water. If you want some flavour, try infusing your water with fresh-cut fruit (lemons or limes), herbs (mint or basil), or vegetables, such as cucumber. If you crave that bubbly feeling, try sparkling water with a splash of 100% fruit juice.

Salty snacks

The Dietary Guidelines for Americans recommends consuming less than 2,300 milligrams (mg) of sodium daily. According to the Centers for Disease Control and Prevention (CDC), Americans consume an average of more than 3,400 mg of sodium per day.

While sodium and salty foods do not raise blood glucose levels, they can raise blood pressure. High blood pressure (hypertension) and type 2 diabetes often occur together. High blood pressure is seen twice as much in people with diabetes compared to those without diabetes. Both diseases affect the body’s vascular system (blood vessels and lymph vessels that carry blood and lymph throughout the body).

High blood pressure increases the risk of other health problems, such as heart attack, stroke, and kidney disease.

One study compared people with type 2 diabetes to people without diabetes in relation to their salt intake at meals. The researchers found that people who added salt to meals compared with those who never added salt had a nearly twofold increased risk of type 2 diabetes.

Snacks high in sodium include chips, chip dip, pretzels, salted popcorn, salted nuts, frozen prepared snack foods, beef jerky, and deli meats. Look for low-sodium or no-salt-added versions of these snack foods to help keep your sodium intake in check.

Breaded fish

Fish is another food that is a great addition to your diet. Many types of fish, such as salmon, tuna, and mackerel, are high in heart-healthy fats. However, depending on how fish is prepared, it may be doing more harm than good.

Frequent overall fried food intake has been shown to increase the risk of type 2 diabetes. Fish that is breaded and fried can raise blood glucose levels and negatively affect your cholesterol levels so it’s better to avoid these foods for diabetes patients.

A study of over 35,000 Swedish men followed for 15 years concluded that fried fish is associated with an increased risk of type 2 diabetes.

Experts don’t know the exact reason why breaded, fried fish increases your risk of type 2 diabetes. However, some suggest that a higher overall fat intake may be to blame. Also, the fatty acid composition of the food may change during frying, possibly leading to a loss of healthy omega-3 fatty acids and an increase in other less healthy fatty acids.

Additionally, high-temperature cooking, including deep frying, promotes the formation of mutagenic (inducing or capable of inducing genetic mutation) compounds, such as heterocyclic amines, as well as advanced glycation end products (AGEs), which may contribute to insulin resistance.

Next time you have a hankering for seafood, skip the breading on your fish and choose healthier cooking methods, such as broiling, baking, or grilling.

Condiments and salad dressing

Condiments and salad dressings such as mayonnaise, ketchup, barbecue sauce, and non-vinaigrette salad dressings are often sneaky sources of added sugars, sodium, and saturated fats. Using too much too often can add up and take a toll on your health. It may increase your risk for type 2 diabetes.

Making your own sauces, condiments, and dressings at home puts you in charge of the ingredients. Instead of salt and sugar, try adding flavour to your meals with herbs, spices, vinegar, olive oil, citrus, garlic, and other seasonings. At the store, look for low-sugar or low-salt varieties of condiments and dressings.

Summary

Poor dietary patterns may contribute to an increased risk of developing type 2 diabetes. In particular, foods high in refined carbohydrates, added sugars, saturated fats, and sodium have been associated with an increased risk of type 2 diabetes.

In the list for people with diabetes to avoid includes foods such as starchy vegetables, red and processed meats, highly processed fruit, white rice, soda, salty snacks, breaded fish, condiments, and salad dressing. It’s important to note that some of these specific foods have been identified via observational studies.