How the body works; glucose management
The human body is a great machine. It has evolved over millions of years to enable it to thrive and prosper in the world that we live in. It has adapted to changes and is now capable of surviving whether food is in abundance, in short supply or when there is none at all. Without food, the body can usually survive for a few months.
The body likes to be fed, and rewards us when we do so
Over the millions of years, the human body has learned to become omnivorous, in other words, it can eat anything. This includes other animals, birds, fish, plants, insects and fruit. In the early years, humans ate what was available to it due to the season, topped up with meat when it could catch it. In evolutionary terms, nothing has changed. It takes thousands of years for the body to evolve to consume and digest new foods that appear.
The body converts all food into glucose no matter whether it starts as sugar, carbohydrate, or protein. It deals with fat in a slightly different way. It needs energy to operate muscles, organs and the brain.
Though we assume that our bodies do all this work unaided, in fact, we live in a symbiotic relationship with billions of bacteria that live on our skin and in our gut. Without this bacteria we could not digest food and obtain the nutrients that we need. We have good bacteria and bad; it is important to feed the good guys and try to minimise the bad guys.
Energy is measured in calories (actually in thousands of calories), and the typical calorie need is the following:
Male 60 years old, 80 kg, 5 ft 8 ins, moderately active, requires 2,450 calories a day.
Female 60 years old, 80 kg, 5 ft 8 ins, moderately active, requires 2,200 calories a day.
It is interesting that the body requires between 60% and 75% of these calories just to live. So sitting on the couch all day without moving will require possibly only one modest meal a day.
The body can be regarded as being similar to a car engine. The car takes in hydrocarbons and air and from that produces energy and exhaust. The body takes in carbohydrates and air and from that produces energy and exhaust. Just like the car, if you put in the wrong fuel, it does not work very well.
Cells in the body convert glucose plus oxygen from the red blood cells to produce energy and give off carbon dioxide and water. Actually it is the mitochondria in the cells that do the work. Each cell has dozens or even hundreds of these little batteries. This process is known as the Krebs cycle. When oxygen is present for combustion, it is aerobic but the cells can function for a short period without oxygen and this is anaerobic.
The body can run on glucose or fat, with oxygen or without. It operates better with oxygen because anaerobic conversion of fuel produces lactic acid which can build up in the muscles and cause cramp. This is why ladies in childbirth are taught to pant; it increases the oxygen to the muscles and allows the cells to function aerobically and reduce the pain.
The key to glucose management is insulin
Managing the fuel in the body is complex. The body converts food into glucose which enters the blood. The body senses the glucose and tells the pancreas to produce insulin. Insulin in the blood tells the cells to allow glucose in so that it can be burned. If there is still glucose remaining, it tells the liver to store glucose in a condensed form called glycogen. When the liver is full, the insulin puts remaining glucose into fat cells which are like a massive warehouse that can never be full.
When blood glucose levels fall, the pancreas reduces insulin production. When blood sugar becomes low, the liver converts glycogen back into glucose and the cells continue burning glucose. When the glycogen levels have been exhausted, the body switches to fat burning by converting fat into a usable fuel called ketones.
Ideally, cycling between glucose burning and ketone burning should take place every day
When too much glucose (sugar) is taken in over too long a period, the pancreas has to produce an increased amount of insulin. The cells become over tolerant of the insulin and so to get the same effect, the pancreas had to make more. The result is insulin resistance which is one step before Type II Diabetes. Eventually the cells cannot process insulin and the person is described as Type II Diabetic and requires careful diet and sugar management. People who are Type I Diabetic have a genetic fault which means that the pancreas cannot produce insulin.
Some foods take longer to release their glucose. When they are eaten, the level of blood sugar increases but slowly. This is much more healthy and easier for the body to manage. The speed by which the glucose gets into the blood is known and set out on a table, the Glycemic Index
(GI) Table. High GI foods cause sugar spikes which make the person “high” and then crash causing sugar cravings. Healthier eating is targeted at lower GI foods. In general, a GI score above 70 should be avoided, between
70 and 40 is acceptable and below 40 is good.
Many people eat all day, they are the grazers. This is a real problem because the glucose levels never fall enough to initiate fat burning. With high blood glucose levels, fat increases without the mechanism for reducing it. Glucose in the blood and glucose burning produces reactive oxygen species which is very bad for the body.
In addition, glucose in the blood starts the growth cycle, as if the body believes it has just entered summer and the growing time of the year. Whereas winter normally signals a shortage of food and a period of living off accumulated fat, no such situation arises. The body lives in endless summer and growing cycle. The result is tall people who are basically unhealthy.
In conclusion
The western diet has resulted in the population becoming taller but preventing people from cycling between fat burning and glucose burning. This has resulted in a large percentage of the population being obese which affects both lifestyle and longevity. Grazing is particularly unhealthy for people; they would find an immediate benefit from changing their eating pattern to just one meal a day, preferably at lunchtime. This would result in a huge weight loss plus cycling between glucose and fat burning.
Fasting (explained next week) accelerates the healing process are initiates autophagy (in another article later) which is a life changer. Cancer cells only have the ability to consume glucose (and yet another article) so cancer can be controlled/eliminated by cycling into fat burning.