deficit from tdee or bmi?

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I keep reading that to lose 1 pound a week you have to have a deficit of 3500 calories per week. Is this correct?
My bmi is 1439 calories.
My tdee is 1726 calories.
I am doing the 5:2 diet consisting of around 1500 calories for 5 days and 500 calories on the other 2 days. Does this mean I have to subtract 3500 calories per week? I feel like I'm missing something as the weekly calories seem too low.
I'm 42, female,73kgs and am 5"8.

Many thanks for your help xx

Replies

  • dorisopen9
    dorisopen9 Posts: 94 Member
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    With intermittent fasting you create your caloric deficit on the fast days alone. All non fast days you should eat to your TDEE, in your case around 1700 kcal. If you feel that 500 kcal are too much you can reduce the calories on the fast days to a quarter of your TDEE.
  • Sued0nim
    Sued0nim Posts: 17,456 Member
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    If your TDEE is right, which I doubt tbh, you are already cutting 3800 calories per week from it, if you are logging accurately - weighing everything
  • Sued0nim
    Sued0nim Posts: 17,456 Member
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    With intermittent fasting you create your caloric deficit on the fast days alone. All non fast days you should eat to your TDEE, in your case around 1700 kcal. If you feel that 500 kcal are too much you can reduce the calories on the fast days to a quarter of your TDEE.

    Can't see why that would make the slightest difference
  • Sued0nim
    Sued0nim Posts: 17,456 Member
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    Try this http://scoobysworkshop.com/calorie-calculator/

    Unless you do seriously nothing, no walking, climbing stairs, chasing kids then you are probably in the 1-3 hours light exercise range and your TDEE would be closer to 2000
  • Christine_72
    Christine_72 Posts: 16,049 Member
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    If your TDEE is right, which I doubt tbh, you are already cutting 3800 calories per week from it, if you are logging accurately - weighing everything

    I went to the scooby website and it says my bmr is 1449 and my tdee is 1738. To lose weight I should eat 1391 calories per day.
  • Christine_72
    Christine_72 Posts: 16,049 Member
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    I have a desk job and I do not exercise
  • yarwell
    yarwell Posts: 10,477 Member
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    I keep reading that to lose 1 pound a week you have to have a deficit of 3500 calories per week. Is this correct?
    My bmi is 1439 calories.
    My tdee is 1726 calories.
    I am doing the 5:2 diet consisting of around 1500 calories for 5 days and 500 calories on the other 2 days.

    bmR not bmi

    1500 * 5 + 500 * 2 = 8500

    1726 * 7 = 12080

    Existing deficit = 3580 per week - you're on track for a loss around 12 kg in a year.
  • Christine_72
    Christine_72 Posts: 16,049 Member
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    Thank you yarwell, as you can see I'm hopeless at working these things out!