Drop 10 pounds in 30 days..the math behind it :)

skyblu263
skyblu263 Posts: 91 Member
edited October 24 in Health and Weight Loss
I posted this forum about a week and a half ago. But, for those that missed it. Here it is again :)

http://www.myfitnesspal.com/topics/show/807681-how-to-lose-10-20-30-pounds-in-so-many-months
"Hey you guys,
I'm HORRIBLE at math. So, when I finally found a website that actually broke down the numbers on how to lose weight, I was pretty thrilled!
My attempt in November to lose a certain amount failed. I ate horrible. But, I'm not discouraged, just disappointed. Time to try it again for December :)

Anyway, if you ever wanted to lose 10 pounds in 30 days, or 15 pounds in 50 days or whatever, here's the math :) I hope this helps those who have a problem understanding and just need the nitty gritty broken down:

The facts:
3,500 calories equals 1 pound.

The math:
Let's say you want to lose 10 pounds in 30 days.
If 3,500 calories equals 1 pound and you need to lose 10 pounds you multiply 3,500 by 10. (3,500 x 10 = 35,000)
• You need to burn 35,000 calories in 30 days. How much is that a day? (35,000 ÷ 30 = 1,166)
• You need a 1,166 calorie deficit a day to make your goal
{Note: If you want to lose 15 pounds in 45 days or 22 pounds in 60 days, just replace the numbers.}

Now that you have that number, figure out how many calories you will be taking in for that 30 day period.
Let's say you decided to take in 1,400 calories a day.
The math here is add the deficit (1,166) to your daily calorie intake 1400: so, (1400 + 1166 = 2,566)
• You need to burn 2,566 calories a day to make your goal.

The great news! People burn TONS of calories a day just by breathing, driving a car, etc.

So, what's next?

Figure out your BMR (basal metabolic rate) so you know what you need to really burn through exercise alone.
Let's say your BMR is 1800. Here is what you need to burn through exercise alone...the math: (2566 - 1800 = 766)
• You would need to burn 766 calories a day through exercise of whatever kind in order to lose 10 pounds in 30 days.

Something to remember:
This is only math and calories. This is not taking into account hard core workouts like high intensity interval training. So, if you go on the treadmill and stayed on it until you burned 766 calories (if that was your end number) you'd lose your 10 pounds in 30 days.

*Weightlifting adds muscle and muscle burns even MORE calories :D

By the way, for those not familiar with BMR or how to find out yours, My Fitness Pal has a calculator:
http://www.myfitnesspal.com/tools/bmr-calculator

Hope this helps! It definitely helped me and made me feel TONS better to know what I just need to do. Now, if only I just get my butt in gear and do it! lol!"

Replies

  • isisbryan
    isisbryan Posts: 105 Member
    bump
  • curvycarrie
    curvycarrie Posts: 56 Member
    bump
  • Jem97
    Jem97 Posts: 53 Member
    you would want to find your TDEE not BMR for this, but otherwise pretty much how it works
  • plynn54
    plynn54 Posts: 912 Member
    thanks
  • noogie98
    noogie98 Posts: 451 Member
    not at my computer but I want to read this later ~ thanks for posting!
  • kylieab1978
    kylieab1978 Posts: 1
    That's awesome, thankyou.
    I have just started my weightloss journey and needed guidance with how much/how long to excercise each day and this is perfect.
    Thankyou!
  • Soosannah
    Soosannah Posts: 270 Member
    Bump for later
  • afromullet
    afromullet Posts: 1
    I was doing some thinking and doing some math, too -- since we know protein is 4 cals per gram, and I'm assuming muscle is mostly protein (not sure, bu this seems to make sense), and fat is 9 cals per gram. So 3500 cals about equals a pound of fat (~450 grams == 1 lb -- its actually close to 4000 so I dont know where the extra 500 comes from). ~1800 cals is a lb of muscle (again assuming it is all protein; there is likely some water in there too so this is probably a high estimate). I predict that you can and likely will lose weight faster than your cal deficit predicts because you will likely lose lean muscle mass (unless you are strength training) and some water weight as well. Not sure if this is good news. I do think it fits what I have witnessed.
  • terijoestoes
    terijoestoes Posts: 205 Member
    Bump
  • watfordjc
    watfordjc Posts: 304 Member
    I was doing some thinking and doing some math, too -- since we know protein is 4 cals per gram, and I'm assuming muscle is mostly protein (not sure, bu this seems to make sense), and fat is 9 cals per gram. So 3500 cals about equals a pound of fat (~450 grams == 1 lb -- its actually close to 4000 so I dont know where the extra 500 comes from). ~1800 cals is a lb of muscle (again assuming it is all protein; there is likely some water in there too so this is probably a high estimate). I predict that you can and likely will lose weight faster than your cal deficit predicts because you will likely lose lean muscle mass (unless you are strength training) and some water weight as well. Not sure if this is good news. I do think it fits what I have witnessed.

    Adipose tissue is not 100% fat. To quote http://www.sportsci.org/encyc/adipose/adipose.html :

    "Approximately 60 to 85% of the weight of white adipose tissue is lipid, with 90-99% being triglyceride. Small amounts of free fatty acids, diglyceride, cholesterol, phospholipid and minute quantities of cholesterol ester and monoglyceride are also present. In this lipid mixture, six fatty acids make up approximately 90% of the total, and these are myristic, plamitic, palmitoleic, stearic, oleic, and linoleic. Varying the composition of your diet can vary the fatty acid profile in adipose tissue. The remaining weight of white adipose tissue is composed of water (5 to 30%) and protein (2 to 3%)."

    Human muscle is about 16-21% protein.

    Since the variability between people (and cells within the same person) make it impossible to determine the exact caloric value without dissection (and in the case of muscle, even the dissection method uses estimates since separating fat from within muscle fibre is too difficult), and the math to do it is too complex for me, I trust the averages of 3,500 kilocalories per pound of fat and 600 kilocalories per pound of muscle.

    ETA: That is for losses and gaining fat, I'm not sure what the averages are for regaining muscle and gaining muscle. 2,500 kilocalories seems to be touted for bulking, but I think that is the "pound of muscle plus some fat gain that you'll later lose when cutting" figure.
  • ShayTayJay
    ShayTayJay Posts: 3
    Ooh thank god . Youre a blessing . Finally ! I understand ! Those examples was great . Thank you :-)
  • becausemexico
    becausemexico Posts: 20 Member
    i've never had it explained like that before, but it's really interesting. thanks!
  • Siansonea
    Siansonea Posts: 917 Member
    Smacks of effort. Pass. :drinker:
  • neng00
    neng00 Posts: 2
    bump
  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
    *Weightlifting adds muscle and muscle burns even MORE calories :D

    The odds of adding meaningful muscle while in a 1000 calorie deficit are very small. Beyond that, extra muscle burns a very small number of extra calories.

    Best to ignore that effect altogether.
  • gigglesinthesun
    gigglesinthesun Posts: 860 Member
    so for my numbers: that would result in 'only' 260 min of exercise a day ... clearly I have nothing else to do :laugh:
  • Lifeisgood4
    Lifeisgood4 Posts: 120 Member
    Bump
  • chai613
    chai613 Posts: 3 Member
    Thanks very much for this post. I'm going to start putting it to good use! I'll keep you posted..literally.
  • YourThoughtsCreateYourDestiny
    YourThoughtsCreateYourDestiny Posts: 10 Member
    This is very helpful. I figured I needed to do more exercise since I have neither loss nor gained much weight in a little while. Based on my calculations I am only off approx. 350 calories burned from exercise a day. That's not too bad, I just have to switch the type of exercise I do so that can get more bang for my buck given the amount of time I have to exercise each day. See...easy as pie....if I survive! :wink:
  • chelljo12
    chelljo12 Posts: 187 Member
    bump
  • leggup
    leggup Posts: 2,942 Member
    The idea that 1 lb = 3,500 calories is flawed on a very basic level. Yes, 1 lb of pure adipose fat is approximately 3,500 calories. However, when we are losing weight, we're not just losing fat. We're losing some lean body mass. We're losing water weight. The bigger you begin, the larger the % of that 1 lb lost is fat. Lean people tend to lose more lean body mass and retain more fat. Very aggressive low calorie diets tend to erode lean body mass to a greater degree than more conservative diets.

    Additionally, you have to modify the deficit to account for the lower BMR as the month goes on; this is especially true for longer plans. That is why it is a good idea to have MFP recalculate your daily calorie goals every 5-10 lbs you lose. When I first started on MFP at the end of Feb 2014, it told me I could have 1560 calories a day and lose weight at a rate of 1-1.5 lbs/week. It is now telling me to eat 1410 calories a day.

    By the very very basic calculation, if I wanted to lost 10 lbs in 30 days eating 1,410 calories a day with a BMR of 1,718, I would need to burn 858 calories every day. To burn that, I would have to:

    1. Jog (moderate pace) for 72 minutes.
    2. Do zumba for an hour and a half
    3. Walk for over two hours uphill.

    Is that really doable every day? No. Is it extremely discouraging? Yes. That's because you don't need the deficit to be 3,500 per lb loss. You also shouldn't try to lose 10 lbs in one month; that's 2.5 lbs per week. It's not sustainable.
  • mildammm
    mildammm Posts: 67 Member
    The idea that 1 lb = 3,500 calories is flawed on a very basic level. Yes, 1 lb of pure adipose fat is approximately 3,500 calories. However, when we are losing weight, we're not just losing fat. We're losing some lean body mass. We're losing water weight. The bigger you begin, the larger the % of that 1 lb lost is fat. Lean people tend to lose more lean body mass and retain more fat. Very aggressive low calorie diets tend to erode lean body mass to a greater degree than more conservative diets.

    Additionally, you have to modify the deficit to account for the lower BMR as the month goes on; this is especially true for longer plans. That is why it is a good idea to have MFP recalculate your daily calorie goals every 5-10 lbs you lose. When I first started on MFP at the end of Feb 2014, it told me I could have 1560 calories a day and lose weight at a rate of 1-1.5 lbs/week. It is now telling me to eat 1410 calories a day.

    By the very very basic calculation, if I wanted to lost 10 lbs in 30 days eating 1,410 calories a day with a BMR of 1,718, I would need to burn 858 calories every day. To burn that, I would have to:

    1. Jog (moderate pace) for 72 minutes.
    2. Do zumba for an hour and a half
    3. Walk for over two hours uphill.

    Is that really doable every day? No. Is it extremely discouraging? Yes. That's because you don't need the deficit to be 3,500 per lb loss. You also shouldn't try to lose 10 lbs in one month; that's 2.5 lbs per week. It's not sustainable.

    I think this is more of an informational post for people to understand what is happening math-wise in your body. It is an oversimplication, absolutely, yet the math isn't that far off, at least in people that have a lot to lose.

    When I first found out that a pound of fat is 3500 calories, it all just clicked in my head. It's not bad luck, genetics, metabolism, what-have-you... It was very freeing, in a way, to know that this weight is just a numbers game.

    I would not suggest trying to lose 10 pounds in 30 days, but it puts all of those magic pill/this one simple trick advertising promises in perspective (just makes you think about it in a realistic way, that maybe those shake advertisers are full of ****).
  • jilly1130
    jilly1130 Posts: 52 Member
    bump
  • elartigue
    elartigue Posts: 12 Member
    hello, Im just seeing this post. I myself have struggled with the scale system. the thought is this. 1. you lose 300 calories today then tomorrow the scale is going to hurt you. is not fair. but imagining that you need to buy a car 30,000 dlls right ? and you save today 300 dlls. then that is good right ? nobody is going to tell you having 300 in the bank towards your car is bad. at the end EVERYONE gets their car. and in reality very low percentage of people can really achieve their dream of losing weight. 30,000 dlls ---> 32,500 calories. then It clicked me. i read somewhere that for a guy 15 pounds is the amount needed to change a size of pants. soooooo I setup a goal for 52,500 calories deficit. (deficit of food + workout) and started to track accumulative amounts towards 15 3,500 goals and 1 big goal of 52,500...... no more scale, I know that when I finish my project the result (whatever it is) will be satisfactory.
  • 5stringjeff
    5stringjeff Posts: 790 Member
    Holy resurrected thread, Batman!
  • bpetrosky
    bpetrosky Posts: 3,911 Member
    thread_necro_zps92d0acb7.gif

    Yowza! The zombie thread apocalypse is upon us!
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