In contrast to most food, fibre has the rare ability to reduce absorption and digestion. Fibre subtracts rather than adds. In the case of sugars and insulin, this is good. Soluble fibre reduces absorption of carbohydrates, which in turn reduces blood glucose and insulin levels. In one study, type 2 diabetic patients were given liquid meals containing 55% carbohydrates with or without the addition of dietary fibre.
Fibre reduced both the glucose and the insulin peaks, despite consuming exactly the same amount of carbohydrates. Fibre acts as an anti-nutrient. Because insulin is the main driver of obesity and diabetes, reduction is beneficial. In essence, fibre acts as a sort of ‘antidote’ to the carbohydrate, which, in this analogy, is the ‘poison’. Carbohydrates, even sugar, are not literally poisonous in normal amounts, but this comparison is useful to understand the effect of fibre.
The Nurse’s Health Studies 1 and 2 monitored the dietary records of thousands of women over many decades. Overall, the risk of Type 2 diabetes increases as the glycemic index increases. This is no surprise. This study was also able to confirm the protective effect of cereal fibre intake. Women who ate a high GI diet but also ate large amounts of cereal fibre are protected against Type 2 diabetes. In essence, this diet is high in ‘poison’ but also high in ‘antidote’ at the same time. The two cancel each other out with no net effect. Women who ate a low GI diet (low ‘poison’) but also low fibre (low ‘antidote’) were also protected. Again the two cancel each other out. But the deadly combination of a high GI diet (high ‘poison’) and a low level of fibre (low ‘antidote’) increases the risk of Type 2 diabetes by a horrifying 75%. This is the exact effect of processing carbohydrates — increased glycemic index and decreased fibre.
The massive Health Professionals Follow-up studied 42,759 men over 6 years, with essentially the same results. A high GI and fibre diet confers no extra risk of Type 2 diabetes. A Low GI and low fibre diet also has no increased risk. But the diet high in glycemic load (poison) and low in fibre (antidote) increases the risk of disease by 217! The Insulin Resistance Atherosclerosis study confirms that fibre is an important protective factor against insulin resistance.
The Black Women’s Health Study demonstrated that a high glycemic index diet was associated with a 23% increased risk of Type 2 diabetes. A high cereal fibre intake, by contrast was associated with an 18% lower risk of diabetes. One of the key steps in weight loss is the addition of fibre. Even better, do not remove fibre from the natural foods that contain it.
Carbohydrates in their natural, whole, unprocessed form, with the exception of honey, always contains fibre. This is precisely why junk food and fast food is so harmful. They are the very definition of highly processed foods. The processing of foods and addition of chemicals changes the food into a form that our bodies are not evolved to handle. That is exactly why they are junk.