A good health and fitness program needs to focus on factors that prevent us from becoming unhealthy. One factor that has definitely a correlation with unhealthiness is obesity. The health consequences for being overweight or obese are vast and may include high blood pressure, diabetes, heart disease, stroke, gallbladder disease, sleep apnea and some cancers to name a few.Losing weight and becoming healthy for obese and overweight people is imperative and well designed fitness software can support this. One way it can be helpful is to calculate a person’s calorie balance and correlate these numbers to their body measurements and vital signs. It is very encouraging and motivating to see yourself lose weight and in the same instance your blood pressure and cholesterol levels go down.Weight loss all boils down to your calorie balance. If your intake is higher then you spend, you gain weight. In part 1, we talked about the calorie intake side of the calorie balance equation. Part 2 describes the requirements for the calories spent module.Let’s start out with the assumption that the calories spent will significantly vary between people and can not be generalized between high, medium and low activity level. We need a more precise method than that. If we look just plainly at the factors that influence our energy spending, we can conclude the following:Larger people will spend more energy than small people. It makes sense that when you move more weight it costs more energy. Younger people will spend more than older people. Males will spend more than females. Tall thin people will spend more energy than short stocky with the same weight. The tall thin person has more body surface and loses more heat. Lean muscled people spend more energy than the average or overweight person with the same weight. Muscles use more energy than fat cells. Active people will spend more energy than sedative people.During a day we execute many activities all with a different length of time and intensity level. Between activities there can be huge differences in intensity level. For instance fishing is way less intense than rowing a boat. Also within the same activity different intensity levels exist. For instance 30 minutes running will cost more energy then 30 minutes jogging or walking. Executing an activity with a high intensity level will spend more energy per unit of time.When calculating the calorie balance, the fitness software should take all the above factors into its formula and adjust the variables automatically. For instance if somebody loses weight, this should be immediately reflected in the outcome. Let’s say I weigh in on Monday and the system calculates 2500 calories spent and two weeks later I weigh again and provided my daily activities were exactly the same but I lost two pounds, the system should automatically calculate the new calories burned taking the 2 pounds lost into account.You should have the ability to create multiple activity plans in the system, individualized per person. Most people repeat their daily activities on a weekly basis, if today is Tuesday, next Tuesday my activities will be pretty much the same. From Monday till Friday the activities may be similar, but they can differ significantly from weekend to weekend.In order to calculate the calories spent during the day precisely, you will need to record all activities, the length of time for each activity and the intensity level it was executed. Doing so could mean a lot of time behind the computer entering all this data. To circumvent this problem, the software should allow you to create a plan that is repeated on a weekly basis with default values. Now you need to only to copy this plan and update the differences from what actually occurred. The actual activities with their time length are noted on an activity worksheet that can be printed on a daily basis. This way your data can be recorded within 30 seconds.Next we need to be able to compare our calories spent with our calorie intake. This can be done in the form of a chart that displays the calorie balance per person over time. See the following example: calorie analysis. This chart makes abundantly clear what your calorie balance is and consequently shows the reason why you lose weight or not lose weight.In the next article I will talk about body measurement and vital sign readings and how they correlate to your work outs, supplement intake etcetera.