Stabilising blood sugar: How nutrition affects your glucose levels

Large blood sugar swings drain energy, drive cravings, and put long-term strain on your metabolism. With the right eating habits you can keep your levels more stable — without avoiding carbohydrates altogether.

What triggers blood sugar swings

Every time you eat carbohydrates, your blood sugar rises — that is normal. It becomes problematic when the rise is very steep and is followed by a sharp drop. This so-called glucose spike causes the pancreas to release a large amount of insulin. When the level then falls too quickly, reactive hunger sets in even though you ate just a short while ago.

Repeated high insulin releases can, over years, reduce the insulin sensitivity of cells. The cells then respond less strongly to insulin's signal, and the pancreas has to produce more — a pattern known as insulin resistance, which is considered a precursor to type 2 diabetes. Not every glucose spike is dangerous, but a chronic pattern of large swings puts strain on the metabolism.

What the glycaemic index actually measures

The glycaemic index (GI) indicates how much a food raises blood sugar compared to pure glucose. White bread has a high GI; legumes have a low one. The concept was developed in 1981 by David Jenkins and colleagues at the University of Toronto and has since become a standard tool in nutrition research.

More practically relevant than the GI is the glycaemic load (GL), which also takes the amount consumed into account. A carrot has a high GI but so few carbohydrates per serving that it barely affects blood sugar. Also key: the GI of a food changes depending on how it is prepared — pasta cooked al dente has a lower GI than well-cooked pasta — and on the combination with fat and protein, as well as the individual microbiome.

Which nutritional strategies stabilise your levels

Fibre slows the absorption of carbohydrates in the gut and dampens the glucose rise. Vegetables, legumes, and whole-grain products provide both soluble and insoluble fibre. Combining carbohydrates with protein, fat, or fibre — rather than eating them in isolation — produces noticeably flatter glucose curves.

Vinegar has been shown in small studies to dampen the blood sugar rise after a meal. The mechanism: acetic acid inhibits certain digestive enzymes and slows gastric emptying. The effects are moderate but measurable. Using a vinegar reduction in salad or apple cider vinegar before a carbohydrate-rich meal puts this mechanism to work in everyday life.

The order in which you eat makes a difference

A 2015 study from the Weizmann Institute in Israel, published in Cell, showed that individual glucose responses to the same foods vary enormously — far more than previously assumed. The researchers attributed a large part of this variation to the gut microbiome.

What helps many people regardless: eat vegetables and protein first, carbohydrates last. Studies by the research group of Louis Aronne show that this simple sequence — vegetables, then protein and fat, then starch — can significantly flatten the glucose spike after a meal, without reducing overall carbohydrate intake.

What you can put into practice

According to the research, five levers make the biggest difference: No isolated carbohydrates — always combine with protein, fat, or fiber. Whole grain over white flour — not because white flour is forbidden, but because whole grain provides more fiber. Vegetables and protein as the first courses. Move briefly after eating: even a ten-minute walk after a meal measurably lowers the glucose spike. Avoid large sugar surges from sugary drinks — liquid glucose is absorbed very quickly.

Those who want to know how their body responds to specific foods can wear a continuous glucose monitor (CGM) — sensors like FreeStyle Libre or Dexcom are now freely available. For people without diabetes this is not a medical must-have, but an illuminating experiment. Many are surprised by how strongly even foods considered healthy, such as oats or bananas, affect their own levels.

Observe and understand with YUTHI

In the YUTHI app you can log meals and energy levels throughout the day to identify patterns: When does the afternoon slump hit? After which meals do you feel full for a long time? This self-observation is no substitute for a blood test, but a first step toward understanding how your body responds to eating habits. If you have blood sugar or HbA1c values from a lab test, you can enter them in the app and track them over time.

Sources

• Jenkins DJ. et al. Glycemic index of foods: a physiological basis for carbohydrate exchange. Am J Clin Nutr. 1981;34(3):362–366.
• Zeevi D. et al. Personalized Nutrition by Prediction of Glycemic Responses. Cell. 2015;163(5):1079–1094.
• Shukla AP. et al. Food Order Has a Significant Impact on Postprandial Glucose and Insulin Levels. Diabetes Care. 2015;38(7):e98–e99.
• Reynolds AN. et al. Dietary fibre and whole grains in diabetes management. PLoS Med. 2020;17(3):e1003053.