The "science" of weight loss

I have been scouring the web for information and advice on successful weight-loss. 9o% of "advice" seems to imply you have to buy something, such as a membership of a club, a book, "special" meals or food or whatever, to lose weight. Well, the "rule" I am following first and foremost is that I must not spend any money whatsoever in the pursuit of weight loss, so by definition most advice is not applicable although you can still pick up nuggets of information for free.

I decided to use "proper" science to aid me in my efforts, which is scientifically proven facts about how diet causes body fat gain and loss in humans. There is a lot of Pseudo science about and some claims made by proponents of the various diet strategies out there are either just plain wrong or take a lot of real science and twist the facts somewhat. Detox seems to be a term used widely that has little scientific creditability, some Low Carb diets seem to imply you can break scientific laws on “Thermodynamics” (more of that later), so finding out what is or isn’t scientifically “true” is a bit of a challenge. One thing is for sure: what you eat is directly related to the amount of body fat you have, but its how this relationship works that appears to be the key to unlocking the reasons for weight loss and gain, and therefore how to lose weight successfully.

Body fat is a result of the human body storing unused energy from what is consumed. A marvellous thing, save what is not needed now for when it might be, but this brilliant function is a double edged sword.

Human evolution has developed this automatic system in the body to deal with times of famine and feast, when food supplies were not as predictable as they are in the modern society. The idea is that when times are good the body stores up energy, humans over-consume, their bodies automatically programmed to know that at some point in the future they may need to rely on their “energy savings” for survival. Since most people these days in the modern world do not encounter famine they tend to never use up these saved stores of energy in their bodies as they have no need to, hence they put on weight if they are eating too much, (which it seems most of us are pre-disposed to do when times are good, which they perpetually are in the modern world). The end result is that a large proportion of people in the modern world are likely to be overweight to some degree, some more than others, something borne out in numerous studies.
The human body like all living things is a complex machine, and like any machine it requires energy to function, in other words fuel. Body fat and food is converted into energy by the body to supply the muscles, since the heart is a muscle that must never stop- a supply of energy to the body is critical. Food also supplies nutrition, things necessary for the correct function of the systems within the body such as vitamins, minerals, proteins etc. So food is necessary and since no single food gives the full range of nutritional requirements the diet needs to be varied. This all means simply not eating anything at all or just eating one type of food is not a good idea when it comes to weight loss as the body will soon stop working as it is lacking vital nutritional elements, even when stored body fat can supply energy.

The body burns energy at different rates, this is called the Metabolic Rate. Basically it is NOT true that average people have different metabolic rates, which is an excuse sometimes used to explain why some people are fat and others thin. Stored body fat is a result of taking in more energy in the form of food than is being burned off by the body in the Metabolic process. The Metabolic rate can be increased by exercise, so it is more likely that a thin person is either eating less than a fat person or taking more exercise but eating the same. Either way both bodies are functioning in basically the same way with no significant differences. The Metabolic rate can also be increased based on the size of a person, so rather perversely if you take two people the same height, one is overweight or fat the other is a ‘normal’ size and is thin the fat person will burn off more energy from food than the thin person without any additional exercise, simply because their body has to work that little bit harder to do normal things, such as walking or even sleeping. This is due to the extra weight and size of the body. (The heart for instance has more blood to pump round longer distances.) This explains why, when you take a team of professional sportsmen or a random group of soldiers from the same army, they nearly always have similar physiques, even if their heights differ. Their exercise regimes and food intakes are managed and will generally be the same for everyone, so they all have similar amounts of stored body fat.

The potential energy in food is measured in calorific content or calories. Most foods these days are labelled with their calorie content, or if not this information is widely available. This makes it rather easy to calculate how much energy food is providing. The body burns calories at different rates but roughly this will be 1 calorie per minute for a normal person when at rest or sleeping. This means an average human who does literally nothing all day long will still burn 1,440 calories per day. Since most people do not sleep for 24 hours they will require more than this to function and maintain their body fat or weight. The accepted figure for energy requirements for an average person is about 2,000 calories per day. Therefore, if an average person eats less than this amount their body will begin to use up stored body fat and they will begin to lose weight.
The rate of stored energy usage will be increased if the person eating less than their basic energy requirement also takes part in additional exercise, such as jogging or going to the gym resulting in extra calories being required.

Note there is nothing in this basic analysis that says anything about GI, carbohydrate or protein or food combinations or anything else for that matter. Simply put, science makes it clear that weight gain and loss is a simple equation, its all down to how much energy the body requires and how much it receives in the form of food. With all of the seemingly successful "fad" diets and plans the basic overriding similarity between all of them is that they reduce overall calorie intake.

Scientifically then, the key for my “diet” to be successful will be understanding how much energy my food is providing and how much I need, this way I can ensure that my body begins to use the stored body fat as energy and I’ll lose weight.