Collabofit

An interesting analysis of a simple weight-loss strategy by someone from MIT about losing 30 lbs using nothing but the principle of Conservation of Energy.

Want to lose a pound of fat? You can work it off by hiking to the top of a 2,500-story building. Or by running 60 miles. Or by spending 7 hours cleaning animal stalls. (It is amazing what scientists have actually measured. This last example is tabulated in the book Exercise Physiology by G. Brooks and T. Fahey.)

Exercise is a very difficult way to lose weight. Here’s a rule of thumb: exercise very hard for one hour (swimming, running, or racquetball) and you’ll lose about one ounce of fat. Light exercise for an hour (gardening, baseball, or golf) will lose you a third of an ounce. That number is small because fat is a very energy-dense substance: it packs about 4,000 food calories per pound, the same as gasoline, and 15 times as much as in TNT.

If you run for an hour, you’ll lose that ounce of fat and also a pound or two of water. By the next day, when you’ve replenished the water, you might think, “the weight came right back!” But you’d be wrong-you really did lose an ounce. It is hard to notice, unless you keep running every day for a month or more, and don’t reward yourself after each run with a cookie.

There is a much easier way to lose weight, as we can learn from the first law of thermodynamics. Eat less.

A reasonable daily diet for an adult is 2,000 food calories. That’s 8.36 megajoules per day, or about 100 joules per second-in other words, 100 watts. Most of that ends up as heat, so you warm a room as much as a bright light bulb. Cut your consumption by 600 calories per day and you’ll lose a pound of fat every week. Most diet experts consider that a reasonable goal. Don’t drop below 1,000 calories per day, or you might get lethargic. But at 1,400 calories per day, you can easily maintain an active life.

Of course, there is a catch. You’ll be hungry.

Read the entire article: The Physics Diet

Thanks to JME at the 20 Minute Fitness Solution for the pointer.

Check out what Jeremy Zawodny of Yahoo! fame has done using goal-setting and tracking using spreadsheets — he lost over 50 lbs! Nice!

From his post:

The advice I’ll give isn’t likely to be all that different that what you might read elsewhere, but the combination is what worked well for me. Hopefully it’ll motivate a few more people to do the same. I learned a lot about my habits and behavior in the process and suspect that much of it applies to most people who are struggling with extra pounds.

Diet Tips or How To Lose Weight with a Spreadsheet and a Web Site