How Did You Gain Weight?

This presentation was first placed on the Internet in February 2010.

As an adult male, your life used to be fairly active where your body used up about 2000 Calories per day to do all its necessary processes and another 200 Calories per day to power some exercises, for a total of 2,200 Calories of food energy used each day.

During that day, you ate an assortment of food which contained a total of about 2,200 Calories of food energy.

But then you SLIGHTLY INCREASED the amount of food energy you ate, up to 2,300 Calories per day. You didn't notice that small difference.

But now your body was taking in 2,300 Calories and only using up 2,200 Calories. The result is that you were adding 100 Calories of food energy each day. It turns out that about 3,600 Calories of food energy becomes one pound of human bodyfat. So, after you had added that 100 Calories per day on each of 36 days in a row, you added one pound of bodyfat to your body. In a year of this minor change, you will have added enough food energy to become TEN POUNDS of bodyfat! In five years, you would have gained 50 pounds, and never even realized why.

There is a second way this can happen. Say that you no longer exercised as much as you used to. Maybe more TV or computer games. But instead of burning up 200 Calories each day for exercise, that now drops to 100 Calories per day. So now you are still eating the original 2,200 Calories of food energy each day, but now you are only using up 2,000 for Metabolism plus 100 for exercise, or 2,100 Calories each day. The result is like before, where you would be gaining about 100 Calories of food energy every day. Again, after 36 days of that, your body will have gained one pound of bodyfat. After a year, the gain would be about 10 pounds.

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How can you keep track of this? Nearly everyone thinks that using a bathroom scale will do it. No it won't! If you ate an extra hundred Calories of food content each day, that only creates about 1/36 pound of bodyfat! After 36 days, you would only notice having gained ONE pound of bodyweight! The same effect is true if you either went on a careful diet of 100 Calories LESS than usual (EVERY day!) or did significant exercise workouts where you were able to burn up that 100 Calories or 1/36 pound of body fat. In both cases, a bathroom scale is not nearly accurate enough!

(There ARE exceptions to the common result of a good workout burning off 100 or 200 Calories! Researchers in Antarctica generally need to eat around 6,000 Calories each day to maintain their body weight because their bodies radiate immense amounts of heat due to the constant sub-zero temperatures. Olympic-level athletes need to eat impressive amounts of Calories each day. I understand that Michael Phelps, the swimmer with many Olympic Gold Medals, needs to eat around 12,000 Calories every day, which is partly due to constant physical exertion but is also partly due to his body having to radiate and conduct large amounts of heat to the cool water which he is nearly always in. When professional football players retire, many continue to eat the large quantities of food that they had to eat during their career, and they often rapidly gain huge amounts of weight, which they then have great difficulty getting rid of.)

There are cheap and silly devices which are sold which claim to be able to monitor bodyfat content. The two most common are Bodyfat Calipers and devices which measure the electrical resistance of your body. Both can give you numbers that can make you feel happy, but the fact that both are commonly WRONG by up to 15% of bodyfat, they become useless. If you get a reading from such a device that says you are at 20% bodyfat (a healthy number) the reality could be either that you are actually at 35% (morbidly obese) or 5% (which few professional athletes can accomplish).

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However, there IS a way to accurately measure bodyfat content. The one that is most proven is called Hydrostatic Weighing. Unfortunately, the process is complicated, taking close to an hour to do, expensive, commonly $35 each measurement, and potentially dangerous! We developed a far simpler, quicker (one or two minutes), cheap (generally free), and without any danger at all! It is even fun and competitive for kids, and we think it might aid in correcting the National childhood obesity epidemic. It is described at Accurate and Easy Bodyfat Determination
Bodyfat Analysis Weights - Pepsi Bottles and Pennies
Bodyfat Percentage - Determining Accurate Bodyfat Easily An Automatic Calculator for the above system

Bodyfat - Combating Childhood Obesity Through Motivation

This presentation was first placed on the Internet in February 2010.

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C Johnson, Theoretical Physicist, Physics Degree from Univ of Chicago