New research suggests ultra-processed foods may raise insulin levels despite mild blood sugar impact

Emerging findings indicate that while ultra-processed foods may not spike blood sugar sharply, they can still elevate insulin levels, potentially affecting long-term metabolic health and increasing diabetes risk.

Ultra-processed foods may not raise blood sugar as sharply as many people expect, but new research suggests they can still drive up insulin in a way that could matter for long-term metabolic health. The findings, reported by Everyday Health, surprised the study’s lead researcher, Heather DiFeliceantonio, who said the team had to double-check the results because the blood sugar pattern looked flatter than expected even as insulin rose. That matters because persistently high insulin levels can contribute to insulin resistance, a condition in which the body becomes less responsive to the hormone and one that often appears before type 2 diabetes.

One likely explanation is that many ultra-processed foods are easier for the body to break down than less processed meals. DiFeliceantonio suggested the foods may be, in effect, partially “predigested” by industrial techniques such as high heat and enzymatic processing, which can make nutrients more quickly available. Sandra Zhang, a registered dietitian-nutritionist at Tufts Medical Center in Boston, told Everyday Health that this faster digestion could help explain the heightened insulin response, although the exact mechanism remains unclear.

The researchers stressed that the effect appeared short-lived in the study participants, and the trial itself had limits. It was relatively small, the test meals differed in protein sources, and the ultra-processed meal contained more additives. In real life, the picture may be even more complicated because people often eat larger portions of ultra-processed foods, consume them more quickly and take in more calories overall. Healthline has also reported on broader research linking ultra-processed diets with a higher risk of type 2 diabetes, particularly when those diets are heavy in processed meats, sugary drinks, savoury snacks and ready-made meals.

The wider concern is not just blood sugar, but the way these foods shape appetite, calorie intake and metabolic risk over time. Healthline has reported that replacing even a small share of ultra-processed foods with items such as whole fruit, nuts or plain yoghurt may help reduce diabetes risk, while a review in PubMed points to growing evidence that ultra-processed diets are associated with type 2 diabetes. For that reason, experts are increasingly advising people to make minimally processed foods the default and treat ultra-processed items as occasional choices rather than staples.