Friday, 13 June 2014

Some thoughts on Scientific approaches to weight loss/gain

I am very much excited to write this, since its so much related to my area of work/profession (Biochemistry). Whatever I am writing here are just my thoughts and kindly do not take it for granted. Since I am very well in Biochemistry and other related subjects, I am just trying to explain what actually causes weight loss or gain. This blog post is in drafts since last 3 months, I am very much busy with career related problems and couldn't finish it, had some leisure time since 2 weeks and today I published it.

Weight loss and gain are on top most priority when you are in adolescence. Some want to gain weight, some want to reduce weight by doing rigorous exercises, some want to constantly maintain their weight all the time. Merely eating food or doing regular exercises will not help you in achieving your task , unless you know the "scientific background" of what you are doing. I will start with some basic terms and theories one should know in day to day life if they are really concerned about their weight management. People who don't want any scientific explanations can directly skip to last 2-3 paragraphs.

The whole universe runs on this simple definition "Energy can neither be created nor destroyed" but transforms from one form to other.

In a universe the object of interest is called system, and the rest is called surroundings.

In our case, we (humans or any other organism) are called "System" and the rest around us is called "surrounding".

There is regular exchange of energy happens between system and surroundings in this universe. For example you take a vehicle or a fan, in the former the heat energy is converted to mechanical energy and in the latter the electrical energy is converted to again mechanical energy. The electricity required for a fan comes from heat energy (thermal plant) or a free falling water from a mountain or dam reservoir (Kinetic Energy, Hydroelectricity) or even a nuclear reaction heat energy that occurs in a nuclear power plant.

In all the above cases ,simply the energy is flowing from one system to another in the universe.

calorie : one calorie (cal) is the amount of heat energy required to increase the temperature of water of 1gm weight by 1 degree celsius.
One large Calorie (Cal)= 1000 cal (small cal denoted by lower case "c" whereas large Cal denoted by upper case "C")

Note: For Nutritional value of  food products, some manufacturers denote "Cal" as Kcal (1 kilo calories) to avoid confusion by normal people,both are same/equivalent.

Surface Area : This is the most important term in this article. Simply surface area is the area occupied by an object. This matters a lot in the universe, for example take the following paper

Its an A4 size paper of surface area X

When you fold it one time, the surface area is reduced to X/2

Again if you fold it one more time, the surface area is reduced to X/4

and if you fold it one more last time, the surface area is reduced to X/8

If you carefully observe the weight of the paper remained same in all the cases but the surface area reduced to half upon each fold. Surface area greatly influence your weight, we will comeback to this in later part of the article, 

Now we will move on to actual theory.

Mass Specific Basal Metabolic Rate : It is the amount of energy expended per gram of body mass.

Look carefully at the below chart

The hypothesis is that smaller animals like rat or house mouse requires more energy than bigger animals like elephants. This is because the surface area occupied by rats to their weight is more than the surface area occupied by elephants to their weight.

The conclusion from the above example is assuming your body weight is constant over a period of time, the surface area (simply your  exposed skin to the environment) plays a critical role in weight management. The more you expose your body to the environment, the more you (System) are exchanging the energy (i.e with surrounding)

Seasons greatly affect your weight !

1. In winter, the outside temperature will be mostly cooler than our body normal temperature 37 degrees, which means that your body generates more heat than required to keep your body temperature constant. This means, there is more metabolism of macromolecules (Proteins, Carbohydrates and Fats) for required heat generation. Assuming you are eating same amount of food daily, in winter you decrease weight depending on your body exposure to environment. The more you expose yourself to cold environment, the more you lose weight and vice versa. If your goal is to decrease your weight, winter is the right time for you. Consume average amount of diet daily, do some exercises in the morning, For example swimming is the best exercise to reduce weight, it has scientific basis. If your are swimming in a water pool having temperature less than your body temperature, say 20 degrees centigrade. Your (System) body metabolic reactions will be high and all the energy reserves like fat will be metabolized to produce heat as the water (surrounding) is cool.

2. In summer, the outside temperature is much higher than the body temperatures, which means that your body generates less heat than required as outside temperatures are high and your body exchanges heat from surroundings. This means, there is less metabolism of macromolecules (Proteins, Carbohydrates and Fats) for required heat generation. In summer, if you eat even less amount of food, there is more chance for gaining weight. If your goal is to achieve some weight, you should eat more during summer season.

Note: The hypothesis does not explain anything about the cold blooded animals temperature regulation. The hypothesis is also not applicable to obese people who have genetic influence on their weight. 

Diets : Lets move on to diet components 

Diet plays significant role in weight management. Basically our human body is made of four macro molecules called " Carbohydrates, Proteins, Lipids (Fats) and Nucleic Acids". Out of the four excepting Nucleic Acids, the remaining three have important nutritional value.

Carbohydrates : They meet the major part of our energy demands. They available from the following food sources like Rice, Potatoes, Leafy Vegetables, Root vegetables like carrot, beet root, etc.

Proteins: They constitute the major portion of muscle weight, they are found in Pulses, Grains, etc. They have high density

Fats: They constitute the reserve energy sources of our body and are stored. They have low density compared to Proteins.

Most of the people think wrongly that consuming more fats lead to more increase in weight. Its actually carbohydrates that cause weight gain. Carbohydrates are stored the body along with water molecules. One gram of fat can give six time more energy than hydrated glycogen (Glycogen is storage form of Carbohydrate in Animals).
People who want to gain weight should eat more carbohydrates like rice, potatoes or any other root vegetables, meat etc and for weight loss one should avoid above all but not completely.

For maintaining constant weight over the time, it is advisable to have same amount of food everyday at same time along with a glass of Milk and Egg. Milk contains most of the minerals except iron and Egg contains all vitamins except Vit-C and they are cheaper nutritional foods. If you can afford and available near you, Spirulina is another choice of food. It has the highest nutritional value among all the foods.

I will stop it here. I know I confused most of the people in this post, but if you carefully understand the basics of energy exchange, the rest of the explanation is very much simple. You can also use various health and fitness applications available on your smartphone, go to store and search the. Windows Phone users can download this very useful application Health and Fitness for freeFeedback appreciated in the below comments section.

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