There are 3,500 calories in one pound of body weight. In order to lose one pound, you must expend, or burn, 3,500 calories. If you consume 3,500 calories in excess of your body's requirements, you will gain one pound.
Most people require about 2,000 calories each day to sustain vital organ function and carry out daily activities like washing dishes, brushing hair, driving, etc. If you are a person requiring 2,000 calories per day and consume 2,000 calories per day, your weight will remain steady. No rocket science there.
Unfortunately, anything that you take in over 2,000 calories will be stored by the body as fat - whether that calorie came from protein, carbs, or fat. So if you've been eating an average of 2,500 calories each day, you will gain one pound over the course of a week: 500 calories/day x 7 days = 3,500 calories = 1 pound. On the flip side, by reducing your caloric intake under 2,000 per day, you can start to lose weight. A daily caloric intake of 1,500 would yield one pound of weight loss over a week's time.
Now on to applying the science of calories without carrying a calculator around...
Consider this common scenario: A woman (or a man) says to me, "Lindsey, I don't understand...I'm working out during the week every day and I watch what I eat. Sometimes I cheat on the weekends when I go out, but overall, I'm working really hard and I'm trying. I've been trying to lose 15 pounds for months and months, but my weight just stays the same."
The first question that arises is:
How do you cheat and to what extent?
This woman may be working very hard the majority of the week but not realize the profound caloric consequences of her cheating patterns. Let's say she goes out every Friday with her friends for Margaritas, and usually has about 3 drinks. Then Sunday she hits a BBQ and has 3 beers. Margaritas run about 350 calories each, beers 200. So she could easily (we all know how easily the drinks go down...) take in over 1,500 calories over the weekend. Assuming her other eating habits stay the same, two weekends of this activity would account for nearly one pound, one month of it for two pounds. I speak with people quite frequently who are eating in a manner that supports weight loss/maintenance most of the time, not realizing how insidious and detrimental their indulgences - even when they are sporadic - may be.
So the second pertinent question is:
How hard do you exercise and does it offset the effects of your cheating?
If this woman is taking in an excess of 1,500 calories per week, she needs to expend that additional 1,500 through exercise to maintain her weight and expend even more if she wishes to lose the 15 pounds. Let's say her workout schedule entails five workouts per week - 2 Elliptical sessions, 2 body sculpting classes, and one yoga class. From the details she offers me, I estimate that she burns about 300 calories/workout, putting her at about 1,500 calories each week. This expenditure would effectively cancel out her calorie consumption from alcohol on the weekends, but it would not be enough to fuel her weight loss efforts.
This is a classic example of the manner by which people tend to underestimate the calories they consume and overestimate the calories they expend. It is not necessarily sound logic to say, "Well, I can have this ice cream because I worked out." You have to ask the questions and be honest with yourself about the answers: How are you cheating and to what extent? How much ice cream are you having - a scoop? A pint? You have no idea? Can these calories likely to be incorporated into your body's daily caloric needs? Or have you worked hard enough through exercise to offset the effect of eating the scoop or pint?
There is no need to account for every calorie you eat each day, but having an educated and honest awareness about your body's energy balance may lead to significant improvement in the decisions you make regarding food and exercise. As my friend and yoga teacher, Corina, frequently reminds us in class, "You can have anything you want; but you can't have everything you want." You can have chocolate, Margaritas, and french fries...but you also have to find balance and moderation in order to comingle these yummy foods with fitness goals. Talk to a trainer or nutritionist who can help you understand more about the calories in your particular food/beverage indulgences, and to what extent they are conflicting with your goals.
