The math?

eatingems
eatingems Posts: 106 Member
in Health and Weight Loss
It's not causing me any problems with weight loss, I've just been going with what MFP gives me and it's working for me just fine.

Anyhoo, I was bored and reading about the maths behind losing weight and I can't get my head around it.. "There are approximately 3500 calories in a pound of stored body fat. So, if you create a 3500-calorie deficit through diet, exercise or a combination of both, you will lose one pound of body weight. (On average 75% of this is fat, 25% lean tissue) If you create a 7000 calorie deficit you will lose two pounds and so on."

If my BMR is 1630(ish) and my TDEE is 2000(ish) without exercise, in order to lose 2lbs a week (in theory) I would need to eat 7000 cals less. 2000x7= 14000-7000= 7000 which is only 1000 calories a day?

Now, I'm not implying that's what I'm going to eat. I just would like someone smarter than me to help me understand the math haha! :)

Replies

  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    Basically that means that a 2 Lb weight loss would be too aggressive for your current stats. Yes, that is the math. Also, when using TDEE you should include exercise as TDEE is Total Daily Energy Expenditure...so your actual calorie target would be higher...but probably still too aggressive for your stats.

    More than 1% per week of your body weight is overly aggressive.
  • cee134
    cee134 Posts: 33,711 Member
    Losing 2 lbs a week isn't recommended for people that don't need to lose that much. It would be unhealthy to try to lose 2 lbs a week with only a TDEE of 2000.

    Therefor MFP would never suggest that for you. It would say eat 1200 a day. Which is healthier and more reasonable to get your goals.

    The math works but it's not suppose to be applied to every situation.
  • eatingems
    eatingems Posts: 106 Member
    Thanks guys, I get it now. I was obviously focusing too much on the 7000 and was blind to the fact that I'm eating about 1400 calories a day which puts me in a weekly deficit of about 4200 and I've been losing about 1.5lbs a week on average so, yeah, my TDEE is probably a little bit higher - maybe around 2150 to give me a weekly deficit of 5250 which would equate to that loss?

    1% of my body weight is 1.7lbs so I can see now that it makes sense that the 7000 wouldn't work for me.

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