Friday, September 7, 2007

Some Weight Loss Math

I'll try not to get too much lost in the numbers, but let's take a look at what is needed to gain/lose weight or maintain your weight. The types of food you eat do affect your health and should be considered, but for weight loss, the bottom line:

Rate of weight gain/loss = [Calories you take in] - [Calories you burn]

This gain or loss occurs at a rate of one pound per 3500 calories of calories in excess/deficit of what you need. The second term, how many calories you burn, is made of up your base metabolism (what you burn even while sleeping, sitting, breathing, over the course of a day), calories expended during exercise, and 'thermal effect' of food (what it takes to actually digest your food, which is about 10% of your intake). Some people are more 'gifted' in others in their base metabolism - you know, those guys who can eat absolutely anything and not gain weight. Chances are that instead for some of us merely passing by chocolate can make us gain weight.

The two main factors you have control over are:
1) The number of calories you eat per day (on average)
2) The number of extra calories you burn each day/week with exercise

For most people, the first factor is by far the dominant one, the second factor can be quite important (as well as good for overall fitness). (A third factor would be to increase lean muscle mass by weight and/or resistance training. For those serious about it this can be quite helpful, but for now let's focus on the two main factors.)

Most of you already know that one gram of protein or carbohydrates contains about 4 calories, while fat is 9 calories per gram. There are a ton of resources on the web with the caloric information for most foods. For restaurants and fast food, there are also several good sources, like Shape Fit and Calorie-Counters. These sites also give information on sodium which is helpful to watch.

If you can consistently eat 500 calories less per day than you need, you will lose 1 pound per week, which is a great target over the long term. Actually, for most people anything over 2 lbs per week is far more likely to come back or to lead to yo-yo dieting. Feeling like you need to lose about 20 pounds for 'the big event'. Don't wait until a month before! Four months at about 580 calories per day reduction will get you there.

Liquid calories are especially bad, providing far less feeling of being full and higher in calories than most people think.
A 12 oz can of soda has 150 calories, and the 20 oz bottle has 250.
A large soda at Burger king is 420 calories.
A medium size shake is 500 calories (small around 400, large around 700 calories)

While cutting down (or out) fast food is probably 'best', a less painful 'baby steps' approach is to simply arm yourself with information on the calorie counts for some of your favorite items, and when needed find a better substitute. For example:

KFC's: Chunky Chicken Pot Pie (it's got veggies, so it's healthy??) 770 calories
    Tender Chicken Roast sandwich, no sauce: just 270 calories
    or the Honey BBQ Sandwich, with sauce: 310 calories.
Taco Bell: Mucho Grande Nachos: a whopping 1320 calories, or
    the Grilled Stuffed Burrito: over 700 calories.
    Soft Taco, around 200 calories. Chili Cheese Burrito 330.
Arby's: Roast Chicken Casear weighs in at 820 calories,
    Regular Roast Beef 350 calories.
McDonald's: Steak, Egg and Cheese Bagel is 700 calories,
    Hash browns are just 130, 2 eggs alone are 160 calories.

Small changes and consistently eating a little differently (or a little less), really does add up. Other things being equal (which of course is never the case), a change of one can of soda per day will eventually lead to a weight loss (or gain!) of 10 pounds. (That value comes from 150 calories per day for a soda, divided by a ballpark estimate of 15 cals/day/pound needed to sustain body weight for a lightly active person.)

Suggested action ideas (from least involved to more)
- Make some deliberate change in food choices or portions
   to cut out 500 calories per day
- Look up your favorite fast food or desert calories and see if
   they're reasonable or something that needs to be changed
- Add in some more veggies, fruits, salads (not Caesar, and dressing
   on the side or 'lite')
- Journal what you eat for one week to get the real data on calorie intake
- Set a reasonable goal, set a comfortably long time frame,
   and make a plan to reach it that takes 'baby steps'

Next time I'll look at the important role exercise plays in weight loss.

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