A post above says to burn 1000 calories over what you eat each day -- and this one says 500 calories. Which is right?
Great question! Sorry for the confusion! Essentially 3500 calories = about one pound of body fat. Also keep in mind that every single body is different, so we are always talking about averages and approximations. We also talk in terms of averages and approximations because a lot of the time, we under estimate our calories consumed and over estimate our calories burned. Allowing for the averages and approximations allows for a certain margin of error.
That said, 500 calories daily for 7 days should be 3500 calories a week which would result in around 1lb loss. Again, it would be virtually impossible to ensure EXACTLY a 500cal deficit.
If you're creating a deficit of closer to 1000 calories per day, that would equate to 7000cal deficit for the week and would allow for a closer to 2lb loss for the week.
This is why we state "1-2lbs" per week. Because we aim for the deficit to be between 500-1000 calories daily, and 3500cal burned over what you eat in any time period would equal about 1lb.