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FOR TEENS - The Science behind Weight loss
 

Most people with a weight problem have tried some sort of weight-loss product or programme in the past. Each week the market is flooded with even more new products or programmes. In other parts of the world, particularly in the U.S. parts of Europe and South America and even many parts of East Asia, plastic surgery seems to be the trend, especially when it comes to excess fat because of the speed of a liposuction procedure. Yet, on a daily basis, patients ask us the same three questions:

“How do these diets and products work?”
“How do they differ from each other?”
“Which one is the best?”

Although all three questions are obviously valid, they prove one thing - most people do not even understand the basics. Weight loss is a basic medical science and there is no magic or mystery involved. Besides basic habits, tastes and lifestyles, each patient is also bio-chemically and emotionally totally unique. This makes both the problem and the solution rather complex.

Let us start by looking at the complexity of ‘energy restriction’, or ‘eating less’, as a single entity. On the other hand, many people have a weight problem, not because they eat too much, but because of their abnormal and excessive ability to store energy as fat. Telling these people to eat less makes no scientific sense. They may eventually lose weight with a starvation type diet (800 Cal or less) but their metabolic rate drops and they become biochemical, more efficient at storing energy. Statistically, they almost always ending up heavier than before when their normal lifestyles are resumed.

But besides using ‘energy restriction’ to lose weight, there are many other techniques, all belonging to their own scientific categories and all equally complex. The truth is that most people with a weight problem know very little about the science behind weight loss. It is therefore not surprising that they are very vulnerable to exploitation and failure. How can anybody realistically expect to succeed with anything in life without an understanding of the basics?

In order to lose weight, one can…

1) Decrease energy intake by eating less.
2) Block energy in the intestines and prevent it from entering our system.
3) Slow down the rate at which energy enters our system.
4) Change the "type" of energy that enters our system
5) Influence of the hormones that determine whether energy will be stored as fat or not.
6) Raise the metabolic rate with medication and burn fat.
7) Do cardiovascular (aerobic) exercise.
8) Do resistance (anaerobic) exercise.

All current solutions can be placed into these 8 sub-categories. By the way, if you yourself have tried a weight loss strategy in the past, try and fit your solution into the correct category. Many people are surprised to discover that they have tried the same solution, albeit under a different guise or name, on many occasions in the past. But even worse, they usually also fail for the same reason each time, a reason that they themselves often do not truly understand.

1) Decreasing energy intake by eating less.

This is a large category and most of the better known programmes belong here. Some measure, others weigh food items. Points are often allocated. The dietician, able to deliver a more customised diet for each patient, deserves the tip of the pyramid. At the bottom one finds the hundreds of energy restrictive diets, commonly found in glamour magazines, the back of the breakfast cereal box, the latest fad diet, etc.

If you eat food of a lower energy value, i.e. the low fat diet, you are also decreasing your energy intake.

All surgical procedures to restrict energy intake, such as wiring your jaw, stapling your stomach, inserting an inflatable ring around your stomach, etc. belong to this group.

All forms of medication that suppress your appetite and make you eat less also belong to this category.

But let’s face the facts: energy restriction on its own has failed – nowhere in the world has it statistically proved sustainable results.

2) Blocking energy in the intestines and preventing it from entering the system

The basic principle behind this category is that energy passes your lips but does not enter your system. It allows you to ‘eat more’ but ‘absorb less”.

Chitosan, made from the ground-up shells of shellfish, is a popular and well advertised product, quick to lay claim to these effects. Unfortunately, medical science does not agree, and chitosan has persistently failed to show convincing results in numerous, well orchestrated scientific trials.

Orlistat, a ‘lipase inhibitor’, certainly works, but remains expensive and has some unpleasant side effects like faecal incontinence.

3) Slowing down the rate at which energy enters our system.

Before one can elaborate on this category, one needs to mention the biochemical effects of the hormone insulin. Immediately after a carbohydrate meal, the glucose that is absorbed causes the release of insulin, and levels rise rapidly. Insulin, in turn, stimulates the uptake and storage of glucose by almost all tissues of the body, but especially by cells in the muscles, fatty tissue and liver. This function ensures that glucose is always readily available for energy purposes inside the cell, if and when the cell requires it.

Resting muscle tissue, however, does not need glucose as its source of energy, and uses fatty acids instead. The principal reason for this is that the normal, resting muscle cell membrane is only slightly permeable to glucose, except when the muscle fibre is stimulated by insulin. (As mentioned, this happens after a meal, when rising glucose levels stimulate insulin secretion.) Insulin strongly inhibits the flow of fatty acids from the fatty tissue to the rest of the body, and thereby effectively stops muscle from using fatty acids.

Excess glucose can be stored in liver and muscle cells, by a chemical process that joins individual glucose molecules together in a more space efficient molecule called glycogen. As soon as the ‘glycogen store’ is full, insulin promotes the conversion of all excess glucose molecules into fatty acids. These fatty acids are then subsequently packaged as molecules called triglycerides, and transported to the fatty (adipose) tissue by specialized fat transporting proteins called lipoproteins. In the fat cells, the triglycerides are deposited and stored as fat, which obviously also causes your midline to expand.

In the absence of insulin, however, all aspects of fat breakdown and its use in providing energy are greatly enhanced. This occurs normally between meals when insulin secretion is minimal, but it becomes extreme in Type 1 Diabetes when insulin levels are almost zero. (Type 2 Diabetes is different) During the Type 1 diabetic state, fat deposits are broken down and mobilized so efficiently that extreme concentrations of cholesterol and other detrimental fats fill the bloodstream. Rapid weight loss is also a feature.

If having both too little and too much insulin are detrimental to the body, it becomes clear that something ‘in-between’ is essential. Preventing a surge in insulin by regulating its secretion is obviously also essential to weight maintenance.

The Glycaemic Index (GI) is a new classification of carbohydrates based on the speed of which individual food items release glucose into the system and, therefore, their ability to raise blood glucose levels. Food items with a high GI value raise blood glucose levels much faster than food items with a low or intermediate GI value. If glucose enters the system at a slower rate, less insulin is also secreted. The result is that less fat is deposited.

Various factors affect the Glycaemic Index of food. Individual properties relating to each food substance, the presence of fat, fibre and protein in meals (mixed meals) and different food production or processing techniques are primarily responsible for these variations.

In order to reap any rewards from this category, one obviously needs to educate oneself about the GI values of food.

Medication can also influence the GI value of food.

This category was previously reserved for the diabetic patient, but everyone with a weight problem should incorporate these principles into their daily lives. Because your blood sugar level stays elevated for a longer period of time, it is also a good way to control you appetite.

4) Changing the ‘type’ of energy that enters our system

Basically, it boils down to the effects of insulin once more. As carbohydrates, especially large quantities of the high GI group raise insulin levels and cause the deposition of fat, the theory goes that if one kept your insulin levels low one would obviously deposit less fat. The so-called ‘ketogenic diet’, however, takes this to the limit, and no process can lower serum insulin levels more. ‘Lipolyses’, the medical term for ‘fat-breakdown’, is music to the ears of those that are overweight. As fat molecules (triglycerides) are broken down for metabolic purposes, small carbon-containing molecules (called ‘ketone bodies’) are released. The process is therefore called ‘ketogenesis’. The ketogenic diet says it all – fat is being broken down! Each ketone body contains a small amount of chemical energy, but cannot be used by the body. Ketones (along with their energy) therefore naturally pass through the kidneys and are lost through the urine.

Because insulin is released when carbohydrates are consumed, the ketogenic diet allows you to consume the same amount of energy, but from sources other than carbohydrates, namely protein and preferably unsaturated fats. The process is quite simple; all it involves is to limit or cease the intake of as many dense-carbohydrate food items as possible. The common ones are wheat (which includes all forms of bread and pasta), rice, corn and potatoes.

The late Dr. Atkins is both famous and controversial for his stance on the ‘ketogenic diet’. He has stood alone amongst a sea of criticism from the orthodox dieticians advocating a low fat, predominately carbohydrate diet as the solution to the world growing obesity problem.

The fact of the matter is that a ketogenic diet allows you to derive your energy from sources other than carbohydrate, namely protein and fat, allowing you to fill your stomach with more protein and fat and less carbohydrate for a change. It is therefore referred to as a ‘high protein diet’. Eating less carbohydrate keeps your insulin levels low and causes less fat to be deposited. It also allows you to eat more food than most low calorie diets that some doctors and dieticians torture their patients with.

But, as usual, things are not that quite that simple. Let us imagine that someone ate too much food. This person ate, on average, certain quantities of protein, carbohydrate and fat per day, in a X:Y:Z ratio for example. If this person ate less food, but only less carbohydrate, the X:Y:Z ratio would change, in other words, the fat and protein ratio would now be higher than before. Can one, however, use the term ‘high protein diet’ to describe this person’s new diet? Surely a ‘carbohydrate diminished’ diet would be more appropriate?

To complicate the issue further, all protein sources contain carbohydrate. Glycogen, the store form of glucose, is present in muscle – all meat (muscle) sources therefore contain carbohydrate. Eating ‘more meat’ means that you also eat ‘more carbohydrate’ in a way.

Carbohydrates are made by plants from sunlight. Animals, or rather mammals, are also able to manufacture a carbohydrate source, namely milk sugar (lactose). All dairy products, packed with protein, therefore also contain lots of carbohydrate. All carbohydrate plant sources, however, also contain protein. This includes all grains, fruit, vegetables and legumes. With wheat, probably the most common source of dense carbohydrates consumed in the Western world, the agent that frequently leads to intolerance and allergy is ‘gluten’ - a protein, not a carbohydrate. So, if you eat fewer carbohydrates, you also start eating less protein in a way. From this complexity alone one can see why one should be cautious to make bold statements.

Eating more food and gaining less weight sound almost too good to be true. There are, however, many medical problems and health risks associated with this category.

By the way, there is a new rather impractical theory about your blood group and eating style. The proponent, also a doctor, stands alone amongst a sea of criticism from the scientific community. All individuals with the O-type blood group are told to stop eating wheat. As wheat forms the basic carbohydrate of the Western world these individuals lose weight because of the principles of ketogenesis.


5) Influencing the hormones that determine whether energy will be stored as fat or not.

There are many dishonest and ridiculous claims made in this category. Of the many hormones involved in fat deposition, (consult the section on the role of hormones) only two are of any practical value, namely growth hormone and insulin.

Growth hormone has powerful fat-burning properties, as it opposes insulin’s effects on the cellular use of glucose. It also stimulates the mobilization of fatty acids from fatty tissue, and this mobilized fat is utilized for energy purposes by the muscles in preference to both carbohydrates and proteins.

Growth hormone supplements, sometimes alluded to as ‘secretegogues’, are widely sold by unscrupulous businessmen. The New England Journal of medicine recently published a study that disproves their theory - there is no scientific evidence that it works. Growth hormone in its pure form can certainly not be taken orally, as stomach acid destroys it, and L-arginine, an amino acid required for its production, may help to a minuscule degree, but only if taken in quantities of at least 500mg on an empty stomach. Injecting pure growth hormone is also no solution, as it stimulates the division and enlargement of all cells in the body capable of growing and causes the limbs and face to become disfigured.

There is, however, a wonderful and healthy way to stimulate your body to release large quantities of growth hormone. It’s called exercise.

‘Insulin resistance’ is a medical term that refers to insulin becoming ‘less effective’. The exact reason for this phenomenon is not clearly understood, but for some reason, in the presence of excess body fat, insulin requirements increase because its effects / function become diminished. The end result is that the body compensates by releasing more insulin to do the same job. The end result? More fat gets piled on. (This process eventually leads to type 2 diabetes)

Addressing ‘insulin resistance’ keeps insulin levels in check by lowering blood glucose levels and insulin requirements. There are two ways to address insulin resistance; a) Exercise – this significantly increases insulin’s function and is by far the best method. B) Medication.

An interesting point is that your waist circumference usually determinates the presence of insulin resistance. If you are female with a circumference of more than 88 cm, or male with a circumference of more than 102 cm, you statistically have a good chance of having the early stages of this prevalent condition.

6) Raise the metabolic rate and burn stored fat

Ephedra (and its synthetic derivative ephedrine) is the most commonly used agent in this category. Not popular amongst doctors because of its high side effect profile, it is often disguised with pseudonyms such as Ma huang, Mormon tea and Sida cordifollia in herbal products – all plant species with a high concentration of the ephedrine alkaloid. Most of these agents are ‘sympathomimetics’, meaning that they mimic some of the effects of the body’s own sympathetic (stimulant) hormones such as adrenalin and noradrenalin.

7) Burning energy by doing cardiovascular / aerobic exercise

Many people who are overweight will tell you that they hate their additional fat so much, that, out of desperation, they will do anything to lose weight. When questioned they will also tell you that they have tried every possible diet and have spent a fortune on weight-loss medication. Most of them, however, will also tell you that they are sedentary and do no additional exercise.

Besides burning calories and raising your Metabolic Rate, exercise has numerous other benefits and it is a scientific fact that regular exercise improves life expectancy. This is achieved by improving heart and lung-function, which leads to better blood circulation and increased tissue oxygenation. (This is also applicable, and has been statistically proved to be so, with people who start exercising late in life)

The lesser-known advantages of regular exercise include its ability to regulate your normal sensation of hunger (satiety). It also reduces stress and depression, thereby improving general well-being, self-confidence and self-image. Emotional well-being, in turn, leads to better self-control in all aspects of your life, but especially when it comes to deciding on your food intake.

Exercise is for obvious reasons the easiest way of to tip the Energy Equation towards weight loss and to use that extra fat that your body has been storing for the famine that will never come.

8) Burning energy by doing resistance training / anaerobic exercise.

Resistance / anaerobic training is intended to develop the musculoskeletal system. This implies that not only do the muscles benefit from this form of exercise, but also the bony skeleton. Both these two systems deteriorate with age, and each individual will lose, on average, about 200g of muscle and about 1% of their bone mass per year. Doing regular resistance training will prevent both these degenerative conditions.

This category is suited to everyone and even mature ladies will benefit from regular resistance training. Resistance training is a powerful stimulus for the release of growth hormone, a powerful fat-burning substance. Of all the bodily tissues, the muscle is the biggest consumer of energy. A stronger, more developed muscle also needs more energy during rest, laying true claim to the popular advertising statement ‘burn fat whilst you rest’.

You do not have to go to gym to do weight training - our programme gives you a basic set of exercises that you can do in front of your TV with a set of dumbbells.

The Role of Hormones

The hormonal system is also referred to as the endocrine system, and is responsible for regulating most biochemical processes which take place within the body. These biochemical processes can all be switched on, turned up or down, or switched off, directly as a result of the particular hormone that is responsible for the regulation of its specific chemical function.

Hormones are released into the system and circulate through the body until they reach their place of work. Some travel far, while others go to work just around the corner. Their functions are determined by their design, and they are therefore only able to “touch or tweak” certain “levers and switches”.

The medical term for the “levers and switches” that hormones interact with is “receptor” and every cell in the body has a fair number of these. Receptors mimic door locks, allowing only certain keys (hormones) to unlock them. Once “unlocked” or activated, numerous biochemical processes begin within the cell.

The endocrine system is vast and complex, and not surprisingly, many things can and will go wrong. Some hormones have more than one function. Too much or too little of one function may not matter, but too much or too little of another may be detrimental. Hormones often oppose each other, affecting the final outcome of the intended biochemical process either for better or for worse. Many factors influence their behaviour, which often lead to disease. Drugs are designed to mimic or inhibit the effects of hormones, which explain their high side effect profiles.

It is common for patients with a weight problem, especially those with an excessive energy storing ability, to blame their hormones. Scientists totally agree. The only problem is that although many people have inherited a combination of hormonal tendencies that lead to the excessive storage of fat, the knowledge of such an abnormality offers little to no practical solution. Treating the endocrine system is in some ways like fixing a computer with a sledge hammer.

Even worse, the engorged fat cell, or adipocyte, previously thought to have a mere energy storage and insulation function, is now recognised as an important endocrine organ, releasing many hormonal like substances that lead to disease. Even worse, in the presence of excess body fat, many normal hormonal functions become impaired, making weight loss even more difficult. (See insulin, leptin and growth hormone)

Fat metabolism, fat deposition, appetite control and especially the regulation of the basic metabolic rate, are all affected by the following hormones:

 
 
 
 
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