Dietitians explain which foods may worsen insulin resistance when eaten frequently and what to choose instead for steadier blood sugar.
Key Points
- Food and lifestyle choices can impact your risk of insulin resistance.
- Sugary drinks, refined grains, baked foods, and ultra-processed foods are some of the worst.
- For better insulin sensitivity, eat plenty of protein and fiber and move your body.
If you’ve been told you have insulin resistance, one of the first questions that may come to mind is: What foods should I avoid? And for good reason. What you eat can play a role in how your body manages blood sugar. Insulin is the hormone that moves sugar out of your bloodstream and into your cells, where it gets used for energy. With insulin resistance, your cells stop responding to that signal the way they should, so blood glucose remains elevated for longer, and your pancreas has to work overtime to compensate.
“Insulin resistance means your cells stop responding efficiently to insulin, so your pancreas pumps out more of it just to keep blood sugar in range,” says Caroline Thomason Bunn, RD, CDCES. Over time, that strain can progress to prediabetes or type 2 diabetes, and it’s also linked to heart disease, PCOS, and fatty liver. The good news is that your eating habits are one of the most practical places to start. Here are five foods dietitians say are worth eating less often, and what to reach for instead.
1. Sugary Drinks
If you change one thing, make it this one. Soda, sweet tea, lemonade, sweetened coffee drinks and energy drinks deliver a large dose of sugar without the fiber, protein or fat that would normally slow things down. “These sources of liquid sugar hit the bloodstream fast with nothing to slow it down,” says Thomason Bunn.
Higher intake of sugar-sweetened beverages is associated with a greater risk of type 2 diabetes, and each additional daily serving raises that risk. “We know this is largely because fructose is metabolized in the liver in ways that raise triglycerides and drive insulin resistance,” Thomason Bunn explains.
Portion size compounds it. “The high amount of liquid sugar is rapidly absorbed and easy to consume in larger portions,” says Sheila Patterson, RD, CDCES. Swap sweetened drinks for water, sparkling water, unsweetened tea or coffee.
2. Refined Grains
Refined grains and the products made with them, like breads, crackers and cereals, tend to be low in fiber. “Because they’ve been stripped of fiber and their nutrition, your body absorbs them much faster than whole foods,” says Thomason Bunn. Blood sugar rises quickly, and your body releases more insulin to bring it back down. “That can sometimes cause a blood sugar ‘crash,’ leaving you feeling hungry, tired, and craving more quick carbs,” she adds.
No single grain is the problem, and research on refined grains as a category is mixed. However, the benefits of choosing whole grains are more consistent, with higher whole-grain intake associated with a 21 percent lower risk of type 2 diabetes.
“Choosing higher fiber options like whole grains and pairing with protein, healthy fats and non-starchy vegetables can help slow digestion and may be more likely to support stable blood sugars,” says Patterson. Brown rice, quinoa, farro and barley are easy swaps to get more fiber-rich whole grains in your day.
3. Baked Goods
Doughnuts, muffins, croissants and cakes are typically made with refined flour and contain a concentrated amount of added sugar. “Your pancreas responds by releasing a large amount of insulin to bring blood sugar back down,” says Thomason Bunn.
Occasionally, that’s fine, but making it a daily ritual is where blood sugar takes a hit. “When this cycle happens over and over, your body has to keep pumping out lots of insulin, which may contribute to insulin resistance over time,” she adds.
Higher intakes of added sugars are associated with an increased risk of type 2 diabetes. If you love a morning pastry from time to time, both dietitians suggest pairing it with a protein like eggs or Greek yogurt to slow digestion and soften the blood sugar rise.
4. Ultra-Processed Foods
Ultra-processed foods are typically made with industrial ingredients and tend to be lower in fiber. This broad category includes sweetened drinks, processed meats, cereals, packaged snacks and frozen meals. “Highly processed snack foods and desserts that combine refined carbohydrates with added sugars and saturated fats may also make it more difficult to maintain healthy blood sugar when eaten frequently,” says Patterson.
Overall eating patterns appear to matter more than any single product. Research has linked higher ultra-processed food intake with a greater risk of type 2 diabetes.,
However, not all ultra-processed foods show the same association. Processed meats and sweetened beverages are among the categories most consistently linked with higher risk, while cereals, breads and packaged savory snacks have shown mixed or even inverse associations in some studies., It’s not just about the level of processing, but the ingredients and nutrients in the food.
Rather than avoiding every packaged food, focus on building most meals around minimally processed foods and limiting the categories most consistently associated with poorer blood sugar outcomes.
5. Foods High in Trans Fats
Artificial trans fats have largely been removed from the U.S. food supply, but trace amounts may still remain in some processed foods. Products containing less than 0.5 grams per serving can be labeled as having zero grams of trans fat, so checking the ingredient list for “partially hydrogenated oil” can help identify them.
Why it matters for blood sugar comes down to cell structure. Trans fats can damage cells through inflammation and oxidative stress responses in the body. Thomason Bunn adds, “When that happens, insulin has a harder time sending its message to let sugar move from your bloodstream into your cells.”
Other Tips for Insulin Resistance
What you add to your routine matters as much as what you limit. These habits can help support insulin sensitivity:
- Start with your drinks. “Cut back on sweetened beverages first,” says Thomason Bunn. “This is the highest-impact single change you can make to impact your blood sugar today.”
- Eat consistently. Skipping meals can make blood sugar harder to manage by increasing the likelihood of overeating later. As Thomason Bunn notes, “regular, balanced meals can help regulate blood sugar levels all day long.”
- Prioritize fiber and protein. “These both slow carb absorption and blunt the post-meal glucose spike,” says Thomason Bunn. Fiber-rich choices include beans, lentils, whole grains, whole fruits, non-starchy vegetables and nuts, while lean meats, fish, eggs, dairy and soy foods provide protein.
- Move your body regularly. The American Diabetes Association recommends 150 minutes of moderate activity per week. “Exercise can help the body’s cells accept help from insulin to process glucose more easily,” says Patterson.
It is also important to recognize that food is only one part of the picture. “There are several risk factors that are not within one’s control, including age, genetics, family history and medical conditions that also increase risk for insulin resistance,” says Patterson.
Our Expert Take
Sugary drinks, pastries, some refined-grain foods and certain ultra-processed foods may make blood sugar management more difficult when consumed frequently. They do not need to be off-limits, though. How often you eat them matters more than any single meal. “Instead of focusing on avoiding specific foods altogether, it’s helpful to build most meals around fiber-rich carbohydrates, lean protein, healthy fats, and plenty of vegetables to better support insulin sensitivity over time,” says Patterson.