Weight loss math.

I hate math.

I should have this figured out by now but please help me work through the weight loss math. The first 50% of my weight loss was somewhat easy but this second half is getting tougher. I need to understand the math better.

My BMR is 1445. My daily calorie goal is 1200. If I’m doing the math for the week it comes out to this:

BMR 1445 x7 = 10,115/week calories burned just for living
Calories 1200 x7 = 8,400/week calories to consume
Pound of weight loss = 3,500 deficit/week

10,115 - 8,400 = 1,715 extra calories (BMR minus calorie consumption)
3500 - 1,715 = 1,785 calories in exercise needed (pound of fat minus extra calories)
1,785 / 7days = 255 calories worth of exercise needed per day.

That’s it? If I were to live in a perfect world and consume no more than my exact 1200 calories, all I would need to do is exercise an extra 255 calories worth per day? I feel like I'm missing something. I walk every evening between 3-5 miles at a pretty brisk pace so 255 calories per day really isn't much.

Replies

  • 126siany
    126siany Posts: 1,386 Member
    Don't go by BMR. That's the calories your body needs in a coma.

    You want to go with your TDEE, or Total Daily Energy Expenditure. You calorie deficit should be from THAT number, not from your BMR.
  • martinel2099
    martinel2099 Posts: 899 Member
    I hate math.

    I should have this figured out by now but please help me work through the weight loss math. The first 50% of my weight loss was somewhat easy but this second half is getting tougher. I need to understand the math better.

    My BMR is 1445. My daily calorie goal is 1200. If I’m doing the math for the week it comes out to this:

    BMR 1445 x7 = 10,115/week calories burned just for living
    Calories 1200 x7 = 8,400/week calories to consume
    Pound of weight loss = 3,500 deficit/week

    10,115 - 8,400 = 1,715 extra calories (BMR minus calorie consumption)
    3500 - 1,715 = 1,785 calories in exercise needed (pound of fat minus extra calories)
    1,785 / 7days = 255 calories worth of exercise needed per day.

    That’s it? If I were to live in a perfect world and consume no more than my exact 1200 calories, all I would need to do is exercise an extra 255 calories worth per day? I feel like I'm missing something. I walk every evening between 3-5 miles at a pretty brisk pace so 255 calories per day really isn't much.

    Ok time to forget all of that nonsense, you are over thinking it.

    I recommend that you practice IIFYM method of calorie counting, (If it fits your macros) and do not eat back your exercise calories. You need to chose a daily calorie amount that accounts for your active liftstyle. If you exercise consistently each week that wont' be a problem.

    Your starting number will be an estimate that requires adjustment with time. I recommend that you check out this video by vismal, he's a guy on the community that really knows his stuff.

    How to Calculate Calories and Macros for an IIFYM Fat Loss Diet.
    https://www.youtube.com/embed/7cc18wLJW3k?list=UUXDX5yHGUm5xIKv46yxm9JA

    how to determine macros- http://youtu.be/7cc18wLJW3k

    IIFM for beginners
  • Jim_Barteck
    Jim_Barteck Posts: 274 Member
    To answer your basic question: Yes, your math is correct.

    As another commenter pointed out, your BMR would be applicable if you were completely bed-ridden, which you obviously aren't. If you were to eat to this plan and get 255 calories of exercise per day, you would likely lose even more than 1 lb. per week as simply walking around your house burns more calories than being bed-ridden.

    It's not an awful place to start; however, MFP really does make it easy for you by giving you appropriate calorie targets depending on how much you currently weigh and how quickly you want to lose the weight. As the other commenter said, don't overthink it. Just set yourself on a guided MFP goal, and make sure you're logging *everything* you eat. You'll lose the weight.
  • RHachicho
    RHachicho Posts: 1,115 Member
    Eating under your bmr is ill advised unless you are extremely obese. And even then not by much. Your bmr is the calories your body needs for basic functions. If you don't even give it that and exercise on top then you will definitely be dipping into emergency energy sources. And that means your muscles, your bones and in extreme cases your internal organs.

    You're here to loose fat right? Sorry but your body's capacity to burn that is limited. You can't just starve yourself and expect your waistline to shrink without consequences.
  • inneedofanap
    inneedofanap Posts: 63 Member
    Thanks to you all. I knew I was over-thinking but it's nice to know my math is correct. :)
  • samsaints
    samsaints Posts: 6 Member
    you know im exactly the same im kind of getting it but still not completely so your not alone..keep up the good work :)