Weight Loss and Energy Balance: What It Means For You

By Joe Chaitkin
Fitness Director, West Chester YMCA

So the summer is fast approaching and you want to look good in that bathing suit you just bought. What do you do? Start dieting? Exercise everyday? Take a Supplement? Well what most people don't understand is how the body actually loses fat weight. For every fad diet out there, there seems to be a different theory on how this works. However, there is one way and one way only that the body disposes of unwanted body fat. It's called energy balance and here's how it works:

Energy balance is the amount of energy that you intake versus the number of calories that you burn. Typically, this is discussed in terms of days, but that isn't necessarily how it works. In order to lose 1 pound of fat weight you must burn 3500 calories more than you consume. While on the other hand you must consume 3500 extra calories to gain one pound of fat. To most people 3500 calories is a scary number.

However, if you make a goal to lose 1 pound per week that means that you only have to burn 500 calories more per day than what you consume. This can be done through either diet or exercise alone, but is easier to accomplish if you take a combination approach. Before you try to burn more calories in a day than what you need we will have to figure out how many calories you need. Your daily caloric requirements are referred to as your Basal Metabolic Rate or BMR.

The formula to figure out your BMR is as follows:
Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )

Your BMR represents the total number of calories that you need in a day excluding the extra calories that you might need as a result of exercise or participation in a sport. To factor in your activity multiply BMR by the following:

• If you are sedentary (little or no exercise) multiply your BMR by 1.2
• If you are lightly active (light exercise/sports 1-3 days/week) multiply your BMR by 1.375
• If you are moderately active (moderate exercise/sports 3-5 days/week) multiply your BMR by 1.55
• If you are very active (hard exercise/sports 6-7 days a week) multiply your BMR by 1.725
• If you are extra active (very hard exercise/sports & physical job or 2x training) : multiply your BMR by 1.9

Once you have determined your energy needs you can then figure out how to go about losing fat weight. It is not recommended to attempt to lose more than 2 pounds per week. In fact, an attempt at losing more than 2 pounds per week is unhealthy and often leads to a loss of muscle mass which actually leads to a decreased BMR.

The healthiest and most effective method to weight loss is to exercise and make some small, non-drastic changes to your diet. If you are a big soda drinker replace that with water. If you put a lot of mayonnaise on your sandwiches switch to mustard or relish. Another huge improvement that most Americans can make in their diet is completely eliminating or at the least minimize the number of times they consume fast food. The key is to make changes that can be permanent because once you reach your goals, whatever they may be; you can't go back to your old habits and not expect to regain those unwanted pounds.