Tuesday, September 21, 2010
The Mechanics of Weight Loss
It's been a while since I've discussed the mechanics of weight loss, but I thought it was a good time to go over it again.
The first reality of weight loss is that while losing weight IS a huge bitch, just not gaining it is a bitch.
Let me explain. Several years ago, I resolved to lose 35 pounds. I resolved to increase my exercise regime and eat less, and stick with it no matter how long it took.
To that end, I cut back on calories, and bought a treadmill along with a new TV to put in front of the treadmill. I had been power walking when the weather was nice and time allowed, but I resolved to walk every day no matter what the weather. The treadmill also opened up opportunities to walk since I could do it early in the morning before sunrise, and after school when the kids were home.
The treadmill was delivered and I dutifully walked every day for 45 minutes at a 2 incline at 2.5 miles an hour. I also cut back entirely on processed snacks (only fruit and veggie snacks) and cut back on my portion sizes at all meals.
And, for all that effort, after two months I lost a grand total of one pound.
That sounds awfully discouraging, but the good news is that I lost weight and didn't gain any additional weight. I had been steadily gaining weight for three years, so losing one pound after two months, as opposed to gaining a pound, was a major triumph.
Let me explain. If you want to lose one pound you have to burn an excess of 3,500 calories. Conversely, to gain a pound you have to ingest an extra 3,500 calories over the calories your body otherwise burns.
So if over the last two years you gained 12 pounds (half a pound a month), it means you have to either cut 1,750 calories from your diet a month, or add activities which burn 1,750 a month just to maintain your current weight.
So, in other words, my initial reduction in calories and increase in physical activity merely stopped the weight increase (with a small overall decrease in weight). To actually lose weight I had to cut far more calories from my diet and really increase my physical activity.
And that's the same for everyone. It's easy to get discouraged when your initial efforts result in little or no weight loss. But the reality is, that too many people already have excess calorie intake and not enough exercise, so it's a triumph that you haven't actually gained any more.
But remember, although it's discouraging, it is a start, and despite what the diet gurus tell you, to really lose weight and to keep it off, you have to start slowly and steadily decrease your caloric intake and increase your exercise.
The second reality of weight loss, is that you can probably consume far fewer calories in a day then you think you can just to maintain your current weight--particularly if you're older.
Here's a handy little tool that will tell you how many calories you can consume daily without gaining weight.
After plugging in the information, I found out that this 48 year old female can only consume a total of 1,787 calories a day just to maintain my weight at 130 pounds. Another reality is that as you lose weight, you have to eat less to both maintain that weight and to lose additional weight. For example, if I get down to my goal of 120 pounds, then I only get to ingest 1692 calories to maintain that weight. That's 95 fewer calories a day.
So to lose weight, I have to find some combination of calorie cuts/exercise to burn an additional 3,500 calories. That means that to lose one pound in a week, I have to burn or not eat an additional 500 calories in a day. For example, to lose 1 pound in a week, I could cut 200 calories a day from my daily intake and exercise enough to burn an additional 300 calories a day.
The third reality is that most foods, particularly processed foods are more calorically dense then you realize. A Starbucks cinnamon roll has 500 calories. A Whopper with cheese has 770 calories.
Remember, I can only consume 1,787 calories a day just to maintain my weight. That is not a lot of calories to play with when you start looking at the actual calories in food, particularly processed foods are foods served at restaurants. That Starbuck's cinnamon roll burns up 28% of my daily calories, the Whopper over 43%. Having a "salad" at some chain restaurants may be enough to "blow" your entire caloric "wad" for the entire day.
The fourth reality is that exercise burns far fewer calories then you realize. For example, if you get on a treadmill and set it at a 2 incline and walk at a 2.5 mph pace, you'll only burn about 200 calories in about an hour. There's more calories then that in a bottle of Snapple flavored ice tea.
To burn off a McDonald's breakfast sandwich (300) calories, you have to run 32 minutes at 5 mph. To burn off that Whopper with cheese you have to swim for 94 minutes at a moderate pace. A large order of fries at Wendy's (540 calories) will take 77 minutes of biking to work off.
So, the bottom line here is that to lose weight for real takes a lot of work. It means dramatically revamping your diet to get rid of processed, calorically dense food and exercising harder, and more frequently. It also means learning to just MOVE more during the day, and learning to love foods that provide a lot of filling bulk with minimal calories.