Why is a high-sugar diet bad for you? Sugar can change the gut microbiota in a way that increases intestinal permeability, increasing inflammation. It can also contribute to overeating and obesity, causing many negative changes in the body. Eating a low-sugar, low-glycemic index diet can help balance your blood sugar levels throughout the day, prevent insulin resistance (one long-term effect of a high-sugar diet), protect you from fatty liver disease and heart disease, control your appetite, and keep you fuller and energized for longer.
A low-sugar or sugar-free diet is very similar to what’s called a “low-glycemic index diet.” The definition of the glycemic index (GI) is “a measure of the blood glucose-raising potential of the carbohydrate content of a food, compared to a reference food (generally pure glucose, or sugar).” A food’s GI number tells you how quickly the food is converted into sugar once you eat it; the higher the GI number, the more drastically the food will cause your blood sugar level to increase.
All carbohydrates increase blood glucose (sugar), but this doesn’t mean that all carbohydrates are necessarily unhealthy and should be avoided. Sugary, processed foods impact blood glucose levels a lot more than whole, unprocessed foods. For example, table sugar, white bread, white rice, white potatoes, white flour and all other types of sweeteners have high GI values. Factors that determine a food’s GI value include how much sugar the food contains, how processed it is, the fiber content and what other types of foods it’s paired with (this determines “the glycemic load”).