Over this past semester I’ve discovered something unfortunate. If a person doesn’t get much exercise, snacks when bored, and shops when hungry, that person will tend to gain weight. That person is of course me, and so I’m going to try to do something about it. It’s by no means a new year’s resolution, I’ve been aware of the problem for several months now. And fortunately we’re early in the game yet. My BMI is roughly 25.5, which is just a hair into the “overweight” range. Some of you might be in the same boat, so we might be able to do some thinking about how to best put ourselves where we want.
How to go about losing weight? It’s no secret, the method is very easy. Carrying out the plan is not so easy. Essentially it’s thermodynamics. You put energy in via your food, and use energy in life. Make the latter bigger than the former and you’ll lose weight because that used energy has to come from somewhere. That somewhere is the chemical energy inherent in your fat, assuming you haven’t done some lunatic crash diet that causes your body to pull from other storage sites like your muscles.
The trick is to maintain that negative calorie balance in a way that doesn’t leave you hungry and obsessing about food. My plan is to gradually boost my calories used via walking, jogging, and some weight lifting. I can bump down the calories taken in via replacing less healthy food with things which are filling without being packed with calories.
Just how much is a calorie anyway? Officially in physics it’s the energy which raises one gram of water by one degree Celsius. As it happens, this is 4.18 joules. But complicating matters is the fact that food calories are designated differently, and in fact one food calorie is equal to 1000 regular calories. Intro physics textbooks tell you that the difference is that food calories are capitalized – something like “This cheeseburger has 1200 Calories, or 1,200,000 calories.” In practice I’ve rarely seen this done with any consistency. This is why physics usually just sticks to joules, and in fact why internationally food energy content is actually given in joules as well.
This definition does unfortunately show how one clever weight loss scheme doesn’t work. The idea is to eat all your food cold. Your body will have to spend energy to warm up the food, thus burning some of the calories (or Calories) that you ate. And it’s true. The problem is that if your cold burger weighs some fraction of a kilogram and has to be warmed 10 degrees (or whatever), you’re talking about a few thousand calories – which is just a few actual Calories. So in theory it would help, but I don’t think cold food is worth that pitiful improvement.
Too bad typing isn’t an aerobic activity.
Oh yes, and a minor unrelated milestone! Yesterday we had our 2000th comment here, and I’m immensely grateful for the wonderful and thoughtful quality of all of your commentary. Both the regulars and the occasional visitors have made this blog much better than it ever could otherwise have been. Thanks all!