For many years I was addicted to sugar. Spooning it into my mouth straight from the bag addicted. Just 3 spoonfuls in my tea as people might notice if more went in. Biscuits, cakes, sweets. Most of the pocket money went on sweet stuff.
Needless to say, the dentist was kept busy and soon fillings were taking over the work of teeth. It seemed impossible to cut down. Eventually I managed to cut sugar out of my tea but continued shovelling the stuff in and when chronic fatigue developed sugar was the prime suspect. Cutting out all sugar did seem to help but four years of strict sugar free living later I was back on the sugar and had the addiction under control (so I thought).
At some point in those four years I came across John Yudkin’s book, “Pure, White and Deadly” which laid the blame firmly on sugar for a rise in obesity, diabetes and coronary heart disease. In 1958 Professor Yudkin had written a book advocating a low carb diet. He argued that the amount of sugars, grains and starches in the diet should all be reduced but by the time that “Pure, White and Deadly” was published in 1972 he had decided that the main culprit was sugar.
He decided sugar was the worst of the carbohydrates because it contains no vitamins or minerals, just energy. So if a person eats 2000 calories per day and 400 of them come from sugar then they have to rely on the other 1600 calories to deliver all their daily nutrient requirements which is hard to achieve.
The situation isn’t improved by the way carbohydrates are metabolised in the body. Carbohydrates are metabolised into glucose in the liver after they have been digested in the stomach and the glucose is released into the bloodstream where it is sent to cells around the body to be used as a preferred energy supply. The body will use available glucose for energy before it starts to burn stored fat supplies.
All carbohydrates are converted to glucose in the same way; not just sugar, grains and starches but vegetables and fruits too. What is different is the speed at which they are converted. Sugars, grains and starches are converted quickly while green leafy vegetables are converted slowly.
When glucose enters the bloodstream the pancreas releases insulin to transport the glucose to where it is needed. This works well until lots of glucose enters the system quickly. Lots of glucose causes a lot of insulin to be released to remove glucose to fat cells for safe storage. Too much glucose in the bloodstream, hyperglycaemia, causes major damage to the body and ultimately diabetes.
If large amounts of glucose are removed from the system, low blood sugar, hypoglycaemia results. This makes the brain call for more food because there is not enough energy available for immediate use. Carbohydrates which deliver a lot of glucose lead us to eat too much, too often, storing the glucose as fat.
So sugar packs a double whammy of no nutritional value and fast release of glucose leading to increased fat storage along with seesawing blood sugar levels and this was what lead Professor Yudkin to conclude that it was “Pure, White and Deadly”; the worst of carbohydrates.
However other carbohydrates release glucose more rapidly than sugar. They do contain some nutrients but the nutrients they contain do not compensate for the problems they cause.