Newbie confused about BMR, "eating back" and calorie deficit

grimolive
grimolive Posts: 2 Member
in Health and Weight Loss
I am 25 years old, 5'6" and 160 lbs. I workout every day (usually JM RI30 or NMTZ) and run 5K every other day. I've lost 23 lbs over the past couple of months via exercise and healthy eating. Now, I am trying to get down to about 140 but have been stuck at this weight for about two months, and I'm getting frustrated!

I've calculated my BMR to be about 1500 cals a day. Up until recently I've been eating about 1200/1300 cals a day, which I realize now is probably too little and isn't helping my plateau. So I'm trying to eat more (healthily!) and have done some reading on MFP on eating back your exercise calories and don't really understand. I get that your body needs energy to perform basic funtions and to support itself through workouts, but I thought the key to losing weight was to create a calorie "deficit" wherein you burn more calories than you take in. A deficit of 500 cals a day=1 lb loss in seven days. It's just logic, right? So if I eat back all the calories that I burn from exercise, and eat 1500 for my BMR, where is this deficit coming from and how am I going to lose any more weight? And forgive this very silly sounding question, but if you eat back all the exercise calories what's the point in even exercising at all (even just typing that I realize how silly it is, but I'm honestly confused here!)

I hope my questions make sense and that someone can help me out :) Thanks!

Replies

  • WillMarple
    WillMarple Posts: 12
    MFP takes out 500-1000 calories depending on your goal. I'd explain more but I'm late for a meeting.
  • Momma_Grizz
    Momma_Grizz Posts: 294 Member
    Sorry I'm interested in the answer too and am so glad you asked :smile:
  • Lillouns
    Lillouns Posts: 40 Member
    Instead of eating back calories, I've always liked this calculator from fat2fit radio. It will give you your BMR and calculate the calories you need based on your activity level. http://www.fat2fitradio.com/tools/bmr/ I hope that helps!! I've also never eaten back calories if I work out for less than in hour. I think if you're really really active, it would be wise to eat more.
  • RedHeadDevotchka
    RedHeadDevotchka Posts: 1,394 Member
    I used to be confused as well. LOTS of numbers!
    OK, someone dumbed it down for you me and I was sooooo grateful!

    BMR- calories you burn doing nothing but laying in bed all day
    TDEE-total calories you burn from exercise, and other day to day activities. If you eat at your TDEE calories, its the maintenance amount to maintain your current weight. Doing a 15%-20% cut of the TDEE calories will help you lose weight.


    You can do one of 2 things. Set your calories at BMR and eat back your exercise calories or set your calories at TDEE and not eat them back. With TDEE the extra exercise calories are already worked into your total calories.
    Just depends on what's easiest for you.
  • grimolive
    grimolive Posts: 2 Member
    MFP takes out 500-1000 calories depending on your goal. I'd explain more but I'm late for a meeting.

    I actually haven't been using MFP to count cals or calculate my BMR. I just keep add them up in a notebook, so I don't think my confusion comes from that.
  • dlwyatt82
    dlwyatt82 Posts: 1,077 Member
    BMR is just one point in figuring out how many calories you're burning in total on any given day (or average, if that's what you prefer). If your BMR is 1500, you're burning at least 1800 calories per day even before you factor in your workouts; just getting up and going to work, etc, accounts for some calorie burn throughout the day.

    Sounds like your workouts are pretty intense as well. I don't know exactly what your calorie burns are, but I'd guess somewhere around 500-1000, and you're doing that every day. With that much activity, 1200-1300 calories per day is nowhere near enough. I'd bump up your average calorie intake to around 1800, and make sure you take a rest from the constant, intense workouts every now and then.
  • freezerburn2012
    freezerburn2012 Posts: 273 Member
    I get that your body needs energy to perform basic funtions and to support itself through workouts, but I thought the key to losing weight was to create a calorie "deficit" wherein you burn more calories than you take in. A deficit of 500 cals a day=1 lb loss in seven days. It's just logic, right? So if I eat back all the calories that I burn from exercise, and eat 1500 for my BMR, where is this deficit coming from and how am I going to lose any more weight? And forgive this very silly sounding question, but if you eat back all the exercise calories what's the point in even exercising at all (even just typing that I realize how silly it is, but I'm honestly confused here!)

    The deficit comes from your daily activies, outside of exercise. BMR is an esitmation of the amount of calories your body burns if you were to stay in bed all day.

    The point of exercise is to increase your fitness, not necessarily to control your weight (though it does help).
  • susannamarie
    susannamarie Posts: 2,148 Member
    BMR is not what you burn in a day -- that's what you burn all day without moving at all. Usually your sedentary energy expenditure is about 20% higher.

    I don't really think it's necessary to net your BMR, but I do think it's necessary not to go too low on a consistent basis, especially when you're getting close to goal. You're about 20 lbs off -- why not just set MFP to 1lb/week weight loss, enter your exercise calories (if you're worried about overestimation, start by entering a fraction of the time you actually spend -- I only enter part of the time for Aikido class because part of the time is taken with instruction), and eat what it tells you? If, after a conscientious month, you haven't lost 4 lbs, adjust your calorie goal slightly and continue.
  • msstuard
    msstuard Posts: 131 Member
    Eating back calories are really for people who train hard. You can't have a large deficit if your trying to bulk up and build muscle. It sounds like you are training quite hard yourself so you should be watching your total calorie count. you need a deficit but it can't be too large. The key is figuring out what your calorie count is each day and keep just under to loose weight at a healthy pace.
  • DanaDark
    DanaDark Posts: 2,187 Member
    Exercise will allow you to eat more and also makes the weight loss healthy. Someone that simply diets down to a weight will not look as good as someone that has exercised down.

    It is not advised to eat under your BMR, but some of us have TDEE's that are close to our BMR's.

    Example, me...

    My BMR is about 1500 and my TDEE is 1800. So, to lose weight, I need to eat between 1500 and 1800. But even if I eat just 1500, thats only a 300 deficit. There's no way I can safely lose 1lb a week! So, I have to add in exercise to increase that deficit.

    It is very important to get your BMR at least a day. The reason is that it is VERY difficult to get the proper amount of nutrition (Protein, vitamins, minerals, etc.) a day, if you eat much less than that. It CAN be done, but is generally only safely done through a medically supervised diet.
  • mcarter99
    mcarter99 Posts: 1,666 Member
    MFP takes out 500-1000 calories depending on your goal. I'd explain more but I'm late for a meeting.

    I actually haven't been using MFP to count cals or calculate my BMR. I just keep add them up in a notebook, so I don't think my confusion comes from that.

    In that case there is no need to 'eat back' your exercise, unless you find it helps you lose weight or be more content or something. The thinking is that people are generating too large of a deficit and will be losing more than 2 lbs/week or will get into 'starvation mode' and be losing less weight than their deficit implies. Some people seem to prefer to think they're 'fueling their workouts' with today's calories, not stored calories, too.

Categories