You’ve heard it before: Calories In – Calories Out = lbs lost or gained. But if weight loss is really as simple as this equation suggests, why aren’t more of us actually losing weight?
Why is the process of weight loss so difficult?
The Calorie Defined
Let’s start with the source of it all: the calorie. You can think of a calorie as energy. Your body needs to digest food in order to fuel its many cellular processes, and the energy released during these processes is calories burned.
So here’s the math:
1 gram of carbohydrates = 4 calories
1 gram of protein = 4 calories
1 gram of fat = 9 calories
You can see that fat contains more than double the number of calories per gram that carbohydrates or protein do. What does this mean? It means that by eating a fatty item like peanut butter (1 tbsp), you pack over 200 calories into your body. You could eat 2 ½ apples for that same amount of calories! The term for this is calorie-dense. Nuts, butter, red meat, and most dairy products are ALL calorie-dense. When you are trying to lose weight, you need to get as much nutrition for as few calories as you can – the biggest bang for your buck so to speak. Because fats are naturally so calorie-dense, you really have to watch your portions on these food products when you are trying to cut back on calories. This fact stands no matter how “healthy” the food is.
Now getting back to the math: One pound of fat = 3500 calories. Just one! (Think about how many pounds you’d like to lose, and you get a picture of the kind of numbers you’re up against.) As overwhelming as that figure may seem, it is possible to lose those pounds with no tricks, no magic pills… just simple math. Seriously.
How Many Calories Do You Need?
To determine how many calories you need per day, you must first calculate your basal metabolic rate, or BMR (the number of calories your body needs per day in order to maintain its basic functions). This first calculation equates to about 60-70% of the total calories you burn in a day.
For women, your BMR =
655 + (4.3 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)
For men, your BMR =
66 + (6.3 x weight in pounds) + (12.9 x height in inches) – (6.8 x age in years)
Example:
35-yr-old female, 5’4” tall, weighs 150lbs
655 + (4.3 x 150) + (4.7 x 64) – (4.7 x 35)
655 + 645 + 300.8 – 164.5 = 1436 calories/day
Next you need to account for the other 30-40% of your daily activities – everything from brushing your teeth and walking to your car to your workouts and cooking dinner. Decide which activity level you fall under for an “average” day (as shown below), and multiply your BMR by this figure.
Sedentary: BMR x 1.2 (little or no exercise, mostly sitting)
Light activity: BMR x 1.375 (light exercise, 1-3 days per week)
Most people will fall in these first two categories.
Moderate activity: BMR x 1.55 (moderate exercise, 4-5 days per week)
Vigorous activity: BMR x 1.725 (vigorous exercise, 6-7 days per week)
Extreme activity: BMR x 1.9 (DAILY competitive sports training, marathoner, etc. or a VERY physical job)
Once you have chosen your individual activity level (be honest with yourself!) and done the math, multiply the new figure by 0.1 (10%). This last 10% accounts for digestion and the regulation of body heat, both of which require energy to complete. Let’s use the same example from above:
Example:
35-yr-old female, BMR = 1436 calories/day, light activity
1436 x 1.375 = 1974.5 calories/day
1974.5 x 0.1 = 197.45
Now add them together:
1974.5 + 197.45 = 2172 calories/day
This female requires 2172 calories/day to maintain her weight.
NOTE: Age is factored into the BMR equation because calorie needs decrease every year past the age of 20. So this particular female needs 2172 calories/day this year, but will have to recalculate her needs as she ages and if she gains or loses weight.
Weight Loss Formulas
Now look at a weight loss of 1 lb per week: a realistic goal, especially when first beginning a weight loss program. The idea is to take those 3500 calories you need to lose and divide them up over the course of the week. Essentially, you’re creating a daily calorie deficit. 3500 calories /7 days = 500 calories/day. So in order to lose 1 lb/week, you would need to create a deficit of 500 calories each day.
Five hundred calories per day – that sounds attainable, right? Well it is. But it still takes a LOT of work to achieve, especially on a daily basis. Think about what you’ve been doing so far to lose weight. Do you think you’ve been cutting out 500 calories every day? If you aren’t burning 500 calories in the gym every day (and you shouldn’t be – your body needs at least one day off each week), then your calorie deficit needs to come from your diet. This is almost ALWAYS the hardest part for my clients.
Counting Your Calories
As tedious as it might seem, keeping a food diary is the absolute best way to check your calories. Don’t worry – I’m NOT telling you to diet. As much as you think you know what you’re eating, I guarantee you’ll be surprised by the portions and/or number of calories you’re consuming. Items like butter, sugar, and other condiments can add a significant amount of calories to your meals, and you are less likely to notice them (or count them) if they’re not recorded. Likewise, serving sizes are very frequently underestimated. For example, start measuring your peanut butter and pasta – I bet you’re eating more than you think! (One serving of pasta is ½ cup; peanut butter is 1 tbsp, not 2).
Try keeping a food log for just two weeks at first. A good resource to try: www.dietpower.com. This software program includes an extensive food and exercise database, calculates the number of calories you should be consuming, and gives you a daily “grade”. They also offer a free 15-day trail too, so you can do your 2-week food log experiment at no cost! There are lots of free phone applications and websites that are useful as well.
Making Sure You’re In The Negative
Of course, your calorie deficit should come from a combination of decreased caloric intake and increased exercise. Exercising 45-60 minutes five or six days a week will help you burn calories to reach your daily deficit goal. Using two to three of those days for strength training will increase your metabolism, so you’ll burn more calories no matter what you’re doing! Strength training is so important for weight loss because it actually re-structures your body, making you more efficient at burning fat in the long run. Learn more on the benefits of strength training.
In the end, slow, steady weight loss is the healthiest way to approach your goals. This method will ensure the habits you develop stay in place. Remember that this is a lifestyle change, not a fad. Define your goals in the beginning and be realistic about how long it will take you to get there. It’s a good idea to aim for a loss of 1-2 pounds per week like in the examples. If you lose more than that you could end up losing lean muscle mass rather than fat, which ultimately lowers your metabolism (very bad!). Weight loss takes patience and persistence, but when you know the facts and stick with it, you’ll not only reach your goals – you’ll develop healthy habits that will stay with you for the rest of your life!
For more articles on weight loss, try “10 Ways to Make Weight Loss Work for You.”
Resources:
The Dietary Guidelines for Americans 2005, http://mypyramid.gov/guidelines/index.html
DietPower 4.4 software program, www.dietpower.com
NOTE: There are also a number of apps for your iPhone, iTouch, and other devices that allow you to look up calorie amounts when you’re out at a restaurant or track your calories for the day. Sadly, I can’t recommend any since I don’t have an iPhone – I know, I know, I’m behind the times… That being said, does anyone have application suggestions?
