weight loss for the mathematically inclined

If you don’t mind learning about weight loss from a chubby girl. The way I figure it, no one knows more about losing weight than a girl who’s been battling it her whole life. Unfortunately, knowing the stuff and living the life are two entirely different things 😉

Today I’m going to teach you about your total daily energy expenditure 🙂 You will not need to weigh yourself for one whole week. It will be freeing and empowering. You don’t need to measure your progress on a scale because you will measure it with your actions.

If your weight loss has stalled, here is some sad news. For every 5 lbs of fat you lose, your total daily energy expenditure (TDEE) drops by 50-100 calories. This is part of the reason people see weight loss plateaus. Your body is smaller and doesn’t need as many calories anymore. You need to eat less to compensate.

Keep a notebook in your kitchen. Keep a calculator beside it. That way, every time you go to make a meal, or grab a snack, it’s right there for you to write in. There are also handy (and free!) websites like sparkpeople.com where you can enter your food journals online. Or if you’re going the old-fashioned way with a notebook and pen (like I do!), you’ll want to check out calorieking.com to add up your calories.

Sure, nobody wants to be writing down every bite they take, and carrying around a calculator all day. In a perfect world, we would all eat sensibly, we would stop at 2 cookies, we would not finish off the baby’s waffle. For some, like myself, these are habits we need to learn. It will get easier, and you won’t be doing this forever. You will learn your portion sizes by sight. You will remember the calorie counts for your favorite foods and wont have to look them up anymore. You will work out a rough calorie plan for your day, evenly spaced and sized meals and snacks. And before long, you won’t even be thinking about it. It will be the way you live.

So how much should you be eating? Here is where it gets fun for us math nerds! Your body has a basal metabolic rate (BMR), which is the amount of calories you would burn if you just stayed in bed all day. There are fancy formulas you can use to find this number, and you can read more about those here, but for our convenience, we will use one of these handy calculators. After you’ve figured your BMR, you can calculate your total daily energy expenditure (TDEE). This is your break-even point, the calories you need to maintain your current weight.

For your TDEE, multiply by your activity level for most of the day:
Sedentary = BMR x 1.2 (sit at a desk, driving, reading, or watching TV, and don’t usually exercise)
Lightly active = BMR x 1.375 (light housework, playing with young children, standing work (chef, cashier, sales) or exercise lightly 1-3 days/week)
Moderately active = BMR x 1.55 (heavy housework, walking job (waitress, nurse) or exercise 3-5 days/week)
Very active = BMR x 1.725 (physically demanding job (construction) or hard exercise 6-7 days/week)
Extremely active = BMR x 1.9 (pro-athlete, extremely physical job or very long training sessions, like for a marathon)

Now you have your TDEE. It’s simple math. If your calorie intake is more, you will gain. If it’s less, you will lose. That’s all there is to it! As long as you’re honest with yourself – are you noting everything you eat? are you working out as much as you say? – you cannot fail. (disclaimer: of course, there are some medical conditions that can prevent weight loss, and if your honest efforts are not working, you should talk to your doctor)

It’s so much more empowering to praise yourself for the things you’re actually doing rather than waiting for a number on the scale to change. You can control the things you eat, or the amount you exercise, but you will never be able to control what the scale says. It’s not even an entirely accurate depiction of what’s going on inside your body. With muscle gain and water weight fluctuations, you can easily give or take 2-5 lbs at any point in time!

But this is why it works. When you know your TDEE, and you know that 8 cookies will send you skyrocketing over your limit for the day, then that knowledge might keep you from eating them. Think of it this way, 700 calories over your TDEE, at 3500 calories per pound, is nearly pound of weight gain in just one day. Keep that up, and that’s almost 2 pounds a week! (Can you feel your ass expanding by the minute?) But it also works the other way. On a day that you eat at or below your TDEE, say by 700 calories, you will have a pound weight loss. As you will find out though, it’s a lot harder to burn 700 calories in a day than it is to eat them!

So here is the experiment, and a fun little adventure for math nerds like myself. Why not try to keep a running total of the net calories lost (or on some unfortunate days, gained)? And when you reach the -3500 point, you’ll know you’ve lost one whole pound of real weight. No scales needed! Focus your energy on what you’re doing, instead of what the scale says. Then commend yourself for every minute of exercise, and every healthy food choice, instead of what pounds are being lost. Because if you’re making honest efforts, the pounds will be lost. You might just find that the best way to get the scale moving again is to ignore it entirely.