Let's keep the answer simple; everything that is related to your health.
The most important indicators for your state of health can be measured though your vital signs, like blood pressure, cholesterol level, heart beat, body mass index etcetera. The major input that influence these health indicators are what and how much you eat and drink, smoke, medication use, life style, daily activity and air quality.
Beside our genetic disposition, we are what we eat, drink and breathe.
A good health and fitness software program should be able to capture the above mentioned input and correlate the results with the output, or health indicators. This way you create a cause and effect system that the user can analyze and consequently take corrective measures and improve his or her overall health.
The bigger picture teaches us that an effective health and fitness software program contains modules that can monitor our food intake, record our body measurements and vital signs. Furthermore it should track our daily activities and convert them into calories burned. Also it should keep track of our medicine and supplement intake and monitor our overall health level. For the sport and bodybuilders we need additional modules that can keep track of our workout activities, sport results and fitness tests
Let's start with food intake.
Most of the time we eat together with our family therefore a health and fitness software program should never be restricted to one user.
People tend to repeat the recipes they cook and meals they prepare on a regular interval. For most people this interval is between 20 and 30 days. Furthermore people tend to buy more or less the same ingredients for their meals. For this reason a fitness or diet program boosting databases with thousands of food items will be more of a hindrance than a benefit. The reason that I say this is because it will be very time consuming to pick an ingredient for a recipe or meal plan from a list of thousands of ingredients.
Look for a program that has the basic ingredients to build your recipes and allows you to add food items that are specific to your taste.
A food's nutrition facts change depending on how it is conserved, processed or cooked. For example a cup of canned spinach that is cooked will have totally different nutrition facts than a cup of fresh spinach. Look for a program that can make a distinction between these food properties.
The cost of buying special diet foods can be a lot more (up to 2.5 times) than what the average American spends on food. It is a plus if a health and fitness software program can keep track of the food cost by recipe, meal and day. It is really a bonus if the program can compare grocery prices between shops and help you budget.
A recipe module is imperative to a good health and fitness system. This is the place where you can experiment and adjust your recipes to your diet's nutritional fact limits. The recipe should calculate its nutritional facts per portion depending on the weight ratio of each ingredient that has been added to the recipe. Naturally you should be able to print the recipe and see the total recipe cost and the cost per portion. Having the ability of adding recipe pictures is a plus.
You should also have the ability to create multiple meal plans in the system. Maybe you would like a separate plan for the kids or baby. Or for a partner that has a cholesterol problem, high blood pressure or diabetes. Or you simply want to change diets. These meal plans should repeat over a certain amount of days. The timing of the meals should be more then just breakfast, lunch and dinner. Many diets ask for many small recipe portions during the day. The food items that you select on the meal plan should come from the ingredients as well as from the recipes. For instance you can add a raw apple to your meal plan, which is an ingredient to make an apple sauce recipe. The apple sauce recipe or the raw apple can each be added to the meal plan
As you would expect, the software program should be able to calculate the meal plan cost and nutrition facts by day and for the whole meal plan.
How are you going to keep track of what you actually ate on a particular day and how do you know how to stick exactly to your plan? You do this by printing a meal plan worksheet for a particular day and you note the actual differences from the plan.
We don't have much time in today's busy society; therefore you should be able to register the actual daily food consumption in less then 30 seconds. A system that forces you every day for every meal to select your food items from a list of thousands records is not going to make it in 30 seconds. Only select a system that automatically populates your meal plan for that day and you only update the actual differences from the plan.
Just adding your daily food intake to a database is not going to benefit you. It will create a "data cemetery", data that is never examined. The food data needs to be analyzed and correlated to other types of data like your body measurements or calories burned. Click on the calorie analysis hyperlink to view an example. The chart makes it very quickly clear that the calorie intake line is under the calories spent line and consequently you will lose weight.
Next article I will talk about activity calorie counting and the factors involved.

About The Author

© Erik Pijcke is founder and CEO of Pycke Inc. He is the architect and developer of Hythial Pro, an all-inclusive personal health and fitness software program. Part of this software program contains a comprehensive calorie counter module. You can download this program at http://www.hythial.com.
Hythial Pro - Health Diet Fitness Software + Free Online Recipe and Food Calorie Counter