Glycaemic Responses

One of the most researched areas of nutrition science is how different carbohydrate sources affect blood glucose levels. Understanding these patterns helps explain why different foods produce different physiological responses in the body.

What is a Glycaemic Response?

A glycaemic response is the change in blood glucose levels following food consumption. When we eat carbohydrates, they are broken down into glucose, which enters the bloodstream. The rate at which this happens, the peak glucose level reached, and how quickly glucose returns to baseline levels all constitute the glycaemic response.

Factors Affecting Glycaemic Response

Carbohydrate Structure: Different carbohydrates have different structures. Simple sugars are broken down quickly, while complex carbohydrates take longer to break down. Fibre content significantly affects how quickly glucose is released.

Processing and Preparation: How a food is processed affects its glycaemic response. Whole grain products typically produce slower glucose release than refined grain products, even when containing similar amounts of carbohydrates.

Food Combinations: Eating carbohydrates with proteins or fats slows down the rate of glucose absorption, affecting the glycaemic response pattern.

Individual Variation: People show different glycaemic responses to the same foods due to differences in insulin sensitivity, gut bacteria composition, and other individual factors.

Common Carbohydrate Sources

Refined Grains: White rice, white bread, and refined cereals are processed to remove fibre and bran, resulting in rapid glucose absorption and higher glycaemic responses.

Whole Grains: Oats, brown rice, and whole wheat products retain their fibre, resulting in slower glucose absorption and more moderate glycaemic responses.

Legumes: Beans, lentils, and chickpeas contain both carbohydrates and proteins, as well as significant amounts of fibre, resulting in lower and more gradual glycaemic responses.

Vegetables: Most vegetables contain carbohydrates but in lower quantities relative to their fibre content, producing modest glycaemic responses.

Insulin Response

Blood glucose is regulated by the hormone insulin, which helps cells absorb glucose. When glucose enters the bloodstream, the pancreas releases insulin in response. Different glycaemic responses trigger different insulin responses. Higher and more rapid glucose spikes typically trigger stronger insulin responses.

Practical Implications

Research on glycaemic responses has led to general observations about different carbohydrate sources. However, it's important to understand that individual responses vary significantly, and many other factors—including overall diet, physical activity, sleep, and metabolic health—influence how any given person responds to carbohydrate consumption.