Your energy and nutrient requirements depend on a number of factors. These include, first of all, your sex, age, weight, height and physical activity level. Interacting with an anonymous user, the website lacks this kind of information and can offer only an utterly generalized list of these requirements based on average values. When it comes to energy, it's 2250 kcal per day, and when in comes to nutrient requirements – these are mean values that are based on the requirements of all sex groups over 14 years old. You can read more about the source of these values here.

However, upon registration, you can have these requirements more precise and personalized. You can achieve this by specifying the necessary information via My Metrics page which is accessable from your profile. There, you should press the button "Create" and just input the basic information about yourself: your age, sex, weight, height, physical activity level. Information on your age and sex is necessary to fetch the exact values of your nutrient requirements from the summary tables of the employed source while all the provided data will be plugged into an appropriate equation from the same source to calculate your energy (calorie) requirements.

At this point you should know that you have an option to set your energy and nutrient requirements manually if you do not agree with the source for some reason. In particular, you can overwrite generic nutrient requirements by setting your personal requirements first and checking the corresponding box as you create your metrics, and your calculated energy requirements – by expicitly specifying the desired numbers in the provided fields that become visible when you press the button "set them manually".

You can also specify your prefered macros ratio if you want to. If you create your metrics without setting previously your personal requirements and leave the macros fields empty (or input values which are non-numeric/out of range), the website will apply default values, namely 50pct-30pct-20pct for carbohydrates, fat and protein respectively. If you have your personal requirements set and check the corresponding box as you create your metircs, then leaving these fields empty will result in cancelling the "macros" approach and using instead the macronutrient values you specified in your personal requirements list.

Of course, on My Metrics page, you can manage you metrics too. But please keep in mind that any changes are mostly not retroactive. It means they don't affect your previous statistics that ares based on those metrics except for a present day. Anyway, the edited metrics or generalized metrics (in the case of your metrics deletion) can/will be applied only from the present day.