Calculate your BMR
BMR or Basal Metabolic Rate is the number of kilojoules or calories required on a daily basis to maintain your weight based on your lifestyle.
This figure is useful to know if you wish to lose or gain weight. For weight loss or gain you should aim to consume 250-500 calories or 1000-2000 kilojoules above or below your BMR.
Exercise is a large contributing factor to weight loss - for example, a one hour power walk for a 60 kilogram person expends around 250 calories or 1000 kilojoules.