How much should I eat?

According to the US Department of Health and Human Services in the Dietary Guidelines for Americans inside of My Pyramide published by USDA, they recommended the follow number of calories per day that you should eat:

For a person who practices 30 minutes or less of moderate physical activity, the number of calories that they should eat
Children--------2-3 years old 1000 calories
Children--------4-8 years old 1200-1400 calories
Girls-------------9-13 years old 1600 calories
Boys------------9-13 years old 1800 calories
Girls------------14-18 years old 1800 calories
Boys-----------14-18 years old 2200 calories
Females-------19-30 years old 2000 calories
Males----------19-30 years old 2400 calories
Females-------31-50 years old 1800 calories
Males----------31-50 years old 2200 calories
Females-------51+ years old 1600 calories
Males----------51+ years old 2000 calories

For a person who practices 30 minutes to at least 60 minutes or more of moderate physical activity, the number of calories that they should eat:
Children--------2-3 years old 1000-1400 calories
Children--------4-8 years old 1400-1800 calories
Girls-------------9-13 years old 1600-2200 calories
Boys-------------9-13 years old 1800-2600 calories
Girls------------14-18 years old 2000-2400 calories
Boys------------14-18 years old 2400-3200 calories
Females-------19-30 years old 2000-2400 calories
Males----------19-30 years old 2600-3000 calories
Females-------31-50 years old 2000-2200 calories
Males----------31-50 years old 2400-3000 calories
Females-------50+ years old 1800-2200 calories
Males----------50+ years old 2200-2800 calories