Work against gravity on both the directions

In the GYM, most of the folks lift the weights slowly and put down the weights fastly.
Because, while lifting, they are working against the gravity and
while lowering down, they are working with the help of gravity.

This doesn't efficiently work out your muscles.

Instead of this routine, lift/push the weights at greater speed and
lower the weights slowly.
When you lower the weights slowly, the muscle provides the resistance against the gravity.
This is the efficient way to workout if you really want to improve your muscle mass.
Otherwise, you will not see much improvement.

Why I am Obese or skinny?

Why I am Obese or skinny?
Because of your metabolic rate, food habits, and your life style. Everyone has different metabolic rate. Metabolic rate tells you the amount of energy that is required by a person in a day. If eat high calorie foods, if your total intake calorie is too much and if your metabolic rate is very low, the excess energy will be accumulated in your body and you'll be obese. On the other hand, if your total intake calorie is very less and if your metabolic rate is very high, you'll be skinny.Body can accumulate the Fatty foods very easily. To cut down the excess weight or to avoid putting on the excess weight, Try to eat more protien, high fibre foods, less carbohydrate foods, avoid fatty items totally.

If you want to reduce weight, by simple mathematics, consume less calories than the amount of calories you can burn.
If you want to gain weight, eat more calories than the burning rate. Eat healthly foods, and avoid junk foods. In both the case, To know more details about the food items that you can eat, consult a good dietician.

Last but not the least, make sure you do regular physical activities daily. Include an hour workout in the GYM, swim daily, walk some distance daily, do aerobics, etc.

How do you know your metabolic rate?
Metabolic rate is basically depends on the height, weight, age, and sex. There are approximate calculators available online. http://walking.about.com/cs/calories/l/blcalcalc.htm But they are very rough estimation. There are other factors such as active level, muscle mass, etc. There are impedance based tests, which will tell you a better approximation.

BCA - Body Composition Analysis

Okay, If you want some metrics for you to check your progress, you can check the BCA test.
That gives the total distribution of your weight into various sections like Fat %, Muscle Mass %, Protien content %, Water content %, etc. As you do your workout regularly, you can keep an eye on your BCA, you may take once in a 6 months or so.
BTW, if you hit 10 - 12% of fat, you can see your six pack visibly :)

Check out my BCA report, which was taken few months back. Please zoom the image and check the details, this was a scanned copy.

Commitment and Consistency

Lot of people actually wanted to be fit, but they could not achieve it.
It is not the fault of the fitness program that you follow and you have to follow the Arnold's workout schedule to get into the shape that you like.
It is the basic commitment that you make for this activity.
If you commit yourself and become consistent in your workout, you'll definitely see the results :)
Once you become consistent, it takes 6 months to few years to get into any shape that you want. The time taken depends on your current level and what you want to achieve.
I took almost 6 months to see the difference and by 2 years I felt good change in my body structure.
It also depends on your diet, will write about diet in separate blog