Updated May 02, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Life is all about achieving balance, right?  Well, not if you're trying to lose weight.  If you've achieved an energy balance then you will not lose weight. Energy balance helps you to maintain your weight. If you want to slim down, you need to knock that scale off kilter.

How Do I Find My Energy Balance?

It may take up to a week to accurately calculate your energy balance for the first time.  Energy balance is the difference between your energy input and your energy output.

The numbers you record for energy input and energy output change from day to day. But after a week or so you generally end up with a fairly good estimate.  Once you have your energy balance figured out, take a look at the result.

Here's how to evaluate your final energy balance number.

• Perfect balance: If you end up with a 0 at the end of your energy equation, you've found a perfect energy balance.  In this state you won't gain or lose weight. Perfect energy balance is for people who are in the weight maintenance stage of their weight loss journey.
   
• Positive energy balance: If you end up with a positive number, you've achieved the right balance for weight gain. For some people, like pregnant women, growing children and weight lifters who are trying to bulk up, this is a healthy state.
   
• Negative energy balance:  If you end up with a negative number, you've found the energy imbalance necessary for weight loss.  You've tipped the scales to slim down. For best results you want a negative result of 500-1000 calories per day to lose 1-2 pounds per week.

If losing weight is your goal and your energy equation was either balanced or positive, don't worry. If you found that your balance was negative, but the total falls short of the -500 calorie goal, that's okay too. There are three different ways to change your number and lose weight successfully. 

3 Methods to Adjust Your Energy Balance

There are only three ways to change your energy balance. In short, you have to either reduce your caloric intake, increase your energy output, or combine the two options to achieve the calorie deficit needed for weight loss. The right method for you depends on your health history, your lifestyle and your personal preferences.

• Reduce your calorie intake.  If you can't exercise or if you absolutely hate to exercise, you can reduce your caloric intake by 500 to 1000 calories per day to lose weight.  Once the weight is gone, however, people who choose this option may have a hard time keeping the weight off.  As you slim down, your metabolism changes.  That means that your energy output number decreases and you have to decrease your energy input even more to reach energy balance. In short, you have to eat less. For many people, that is not reasonable.
   
• Increase your physical activity.  You can also tip the scales by exercising more.  But to burn 500-1000 calories every day is very difficult.  Even fit, athletic exercisers need easy workout days or days off to recover and refuel.  Unless you are in a job that involves regular physical movement, this option may not be the most reasonable and it may put you at risk for injury.
   
• Combine increased activity and diet.  Making small adjustments to both your caloric intake and your physical activity is generally recommended as the most reasonable and sustainable method of weight loss.  It is also the best way to maintain your weight after you've slimmed down. 

How Do I Change My Energy Balance Numbers?

To lose one pound per week, experts generally recommend an energy deficit of 3500 calories per week. If you choose the combined method to change your energy balance, you can play around with the numbers to see what works best.  Here's an example:

Dieter: Roger

Current Plan

Calories consumed each day: 2500

Calories burned each day: 2200

2500 (energy input) - 2200 (energy output) =  300 calories

Roger has a positive energy balance of 300 calories. In this state, he will gain weight. To lose weight, he needs a negative balance of roughly 500 calories per day or 3500 calories per week.  To reach his goal, Roger chooses to make modest changes to his diet to decrease his caloric intake by 500 calories per day. Then he will add physical activity to burn more calories. His goal is to burn an extra 300 calories by walking or biking to work. On the weekends, he'll hike with his wife to burn 300 calories per day.

New Plan

Calories consumed each day: 2000

Calories burned each day: 2500

2000 (energy input) - 2500 (energy output) =  -500 calories

With a negative energy balance of 500 calories per day, Roger will have a total calorie deficit of 3500 calories per week and will lose roughly 1 pound per week on this plan.

When you first begin to use the energy balance equation to lose weight, be patient. It takes a week or two to adjust your numbers and see results. And there are many factors that affect your daily energy balance that can make the weight loss process more complicated.  But the energy balance equation is the basis of every weight loss plan and diet. The more you use it and understand it, the more likely you are to lose weight and keep the weight off for good.