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A year without food

One man went to enormous lengths to reduce the width of his girth. Dr Karl weighs up the effects of fasting on the body.

Back in June of 1965, a Scotsman weighing 207 kilograms, described as "grossly obese" and hereafter known only as Mr A B, turned up at the Department of Medicine at the Royal Infirmary in Dundee.

He was sick of being fat and wanted to lose weight by eating nothing and living off his body fat. He told the hospital staff he was going to fast flat out, whatever they said, so they may as well monitor him along the way.

He ended up fasting for one year and 17 days — that's right, he ate no food at all for over a year. He lived entirely off his copious body fat, in the end losing about 125 kilograms of weight.

Treating obesity by total starvation can be dangerous. There are many reports of total starvation leading to death. For example, some people have died of heart failure during the fast, while another died on the 13th day of his fast from small bowel obstruction. Some people have died during the re-feeding period after the fast — one from lactic acidosis.

But to counter this, going hungry is natural. Humans like us (that's Homo sapiens) have been around for the last 200,000 years and for most of that time, food was not always at hand. We evolved to survive with not enough food. Some studies actually show that fasting (or at least, calorie restriction) can have health benefits under certain circumstances.

Once you stop eating, your body gets its energy from the glucose in your bloodstream and liver, thanks to your last meal. You carry a semipermanent 0.5 to 1 kilogram of solids in your gut. The glucose from this runs out after about eight hours.

Then you start burning up a chemical called glycogen. Glycogen is simply a whole bunch of glucose molecules loosely stuck together. It's stored in your liver and muscles. Glycogen is really easy to break down into the individual glucose molecules from which it was made. You can burn glycogen to get the glucose you need for about another 36 to 48 hours.

After two or three days of fasting, you get your energy from two different sources simultaneously. A very small part of your energy comes from breaking down your muscles — but you can avoid this by doing some resistance training, otherwise known as pumping iron. The majority of your energy comes from breaking down fat.

But very soon, you move into getting all your energy from the breakdown of fat. The fat molecules break down into two separate chemicals — glycerol (which can be converted into glucose) and free fatty acids (which can be converted into other chemicals called ketones). Your body, including your brain, can run on this glucose and ketones until you finally run out of fat.

The average non-obese 70-kilogram male carries about 8,000 kilojoules of energy in glycogen, and about 400,000 kilojoules in his body fat.

In the case of our big Scotsman, Mr A B, the staff in the medical school at the University of Dundee kept a close eye on him. He did not eat any food, but the staff gave him yeast for the first 10 months and multi-vitamins every day. Potassium is essential for the proper working of the heart, and when his potassium levels got a little low around the 100-day mark, he was given potassium tablets for about 70 days. He defaecated infrequently, roughly every 40 to 50 days.

Blood samples were taken every fortnight, and his carbohydrate metabolism was checked on nine occasions during the 382 days of his fast. Surprisingly, for the last eight months of his fast, his blood glucose levels were consistently very low. They were around two millimoles, which is about half of the bottom end of the normal range. Even so, he did not suffer clinically from this abnormally low blood glucose level.

His weight dropped from 207 kilograms to 82 kilograms. Some five years later, he had regained only 7 kilograms.

In humans, fasting seems to have health benefits for high blood pressure, diabetes, asthma and epilepsy in children. In animals, fasting seems to reduce the cognitive decline that happens in conditions such as Parkinson's disease and Alzheimer's disease.

One problem with fasting is that you can get cranky and irritable (and sometimes hungry). Another is the lack of companionship with your fellow humans. After all, the word 'companion' comes from the roots 'com' meaning 'with' and 'panis' meaning 'bread'. If you spend lots of time not sharing meals with your kith and kin, you run the risk of becoming an outsider.

So to keep your friends, continue breaking bread — just don't eat it.

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