What's the math?

khristiana

Hi all,

I'm still having a hard time wrapping my brain around "net calories". What is the math for weight loss?

If I strive to stay around eating 1200 calories a day, with cardio 5 times a week for an hour, strength training 4 times a week and walking daily (I have two dogs!), what is the math??

Am I REALLY supposed to eat back the calories I burned off from a work out? In my mind, that's defeating the purpose of "losing weight"...

Please help me understand, as I'm still fairly new to the science of it all. I want to make sure I am doing this right.

Thanks!

blessedmama88

Net calories accounts for your intake (how much you eat and drink) subtracted from your calorie usage (your Basal Metabolic Rate & your burned calories from exercise and other activity). So....
1) figure out your BMR (there is a calculator on this site or you can do it manually (there are a few different methods - I like this one, as it seems to produce the results I expect) For females: 665 + (9.6 x weight in kg) + (1.8 x height in centimetres) - (4.7 x age in years). Remember, figure out the brackets first and then do the addition/ subtraction from left to right.
Once you have got that, multiply according to the following:
Little or no exercise: BMR x 1.2
Light exercise 1-3 days per week: BMR x 1.375
Moderate exercise/ sports 3-5 days p/w: BMR x 1.55
very active hard exercise/ sports 6-7 days per week: BMR x 1.725
Extra active very hard exercise/ sports BMR x 1.9

This gives you the calories to MAINTAIN your weight.

2) use the lists/ calculators on this site to figure out what you are burning through activity.
3) Add BMR and calories burned.
4) Subtract your calorie intake from your BMR+Calories Burned. This will give you your total for the day. Hopefully you end up with a positive number - as this means you are burning more that you are taking in. This is called the calorie deficit. Some people aim to create a calorie deficit that is 20% less than their BMR. I suggest you do a search, and see what suits you.

You have to burn (or create a deficit) of approx. 3500 cals to loose 1 pound. That is a guideline, and some people don't agree with that theory at all. Search it out for yourself and see what you think. Chris Powell (Extreme weight loss) is someone who uses this calculation emphatically.

It's also good to look at the ratio of Carbs/Fat/protein. Again, search some sites, and see what will work for you. When you keep your log here, it tells you how many of each you are eating.

Good luck with your journey! Post again when you have looked into it, and let us know how you go.
Anna

wolfordwebsites

Log everything that goes in your mouth (food, drinks, condiments, everything) and log your exercise. If you put your goals into mfp, it will tell you how many calories to eat. And you can eat back all of your exercise calories. Just have a positive number at the end of the day (1 calorie left or more). You will lose the weight. I didn't believe until I started and that was 7 weeks and 13 pounds ago!

psmd

Sometimes people try eating half their calories back. As long as you're measuring/weighing foods for accuracy, I promise you it works!

ILiftHeavyAcrylics

MFP intends for you to eat them back, especially with a 1200 calorie goal, which is as low as MFP will go. You don't want to create a deficit that is too large, as it can lead to binging, lack of energy, and loss of muscle.

That said, make sure you're logging accurately with a food scale. Or, alternately, only eat back half of them so you have a little buffer.

http://community.myfitnesspal.com/en/discussion/1234699/logging-accurately-step-by-step-guide/p1

khristiana

Thanks for all the info! I bought a digital food scale this past weekend. I do already log all foods, drinks, condiments, etc, as well as all cardio/strength.

I'll figure out my BMR and do the calculations.

khristiana

Ok... I did your calculations from above and got a BMR of 2069. MFP BMR calculator says 2043.

My front page says the following: Goal: 1200 Food: 688 Exercise -391 = 297 NET

What exactly does NET mean? Am I to eat an additional 297 calories?

khristiana

I think I'm figuring it out. So I have to burn more than what I I take every day, to lose weight... Looks like I should go to the gym more than 4 days a week?

khristiana

So, please tell me I got this right:

(2043 +391) BMR + Cals Burned =2434
-Calorie Intake for the day (around 1200)
=1,234

So basically that 1,234 is what is going towards the 3500 to lose one pound, right?

blankiefinder

khristiana wrote: »

I think I'm figuring it out. So I have to burn more than what I I take every day, to lose weight... Looks like I should go to the gym more than 4 days a week?

You don't want to burn more per day than you eat! That's where the 'net' part of this equation comes in.

Keep it simple. Set your goals for a reasonable weight loss per week so that you don't give up and throw in the towel. Exercise. Log it and reduce the calories it gives you for your exercise by half. Don't log anything you do as part of your normal life - cleaning the house, bedroom activities, walking the dog for 10 minutes... that falls under your activity level that you set in your settings (i.e. sedentary, etc). Eat back those 50% of your exercise calories. And most importantly, log accurately and use a food scale!!

You can do this! Read the stickies at the tops of the various forums here for some good, and accurate advice.

LKArgh

khristiana wrote: »

Ok... I did your calculations from above and got a BMR of 2069. MFP BMR calculator says 2043.

My front page says the following: Goal: 1200 Food: 688 Exercise -391 = 297 NET

What exactly does NET mean? Am I to eat an additional 297 calories?

Set your weight loss to something more realistic (I am assuming you have set it to the maximum MFP allows). If your BMR is around 2000, 1200 is too low for you right now, try something in the range of 1500 to 1700.
Then add your exercise calories to this, and start by eating around half of them back (or all of them, if you have an accurate way of measuring what you burn).
So, if MFP estimates you burned 500 calories per day, add around 300 calories or so to what you eat per day. So, if on days without exercise your goal was e.g. 1700 calories, on the day with the 500 calories from exercise, aim to eat around 2000.

If you are losing too fast or feel exhausted after a couple of weeks, then eat more of your exercise calories back. If you are not losing, then go through your logging and figure out if you are underestimating what you eat, or overestimating what you burn.

Lissa_Kaye

Take the 2434 and multiply by 0.8 = 1947. Start around there first. You should lose decently easy. And you could lose more than a lb a week, to 2lbs. See how your body does and adjust accordingly. The more you lose weight, the more you will want to taper down your calories. If you start at 1200 you will stop losing at some point unless you are very petite. Recalculate for every 10-20 lbs you lose.

ILiftHeavyAcrylics

khristiana wrote: »

I think I'm figuring it out. So I have to burn more than what I I take every day, to lose weight... Looks like I should go to the gym more than 4 days a week?

No that isn't what that means. You burn calories just by existing-- that's what your BMR is. Mine is 1400, meaning if I just lie in bed all day and do nothing that's my calorie burn for the day. Since I don't do that it's higher, usually around 1900. As long as I eat less than 1900, I lose weight. I do not need to go to the gym and try to burn off 1900 calories.

There are two ways to go about it and you've got people in this thread telling you both of them. It's important that you don't try to do both at the same time or you'll get yourself in trouble. If you follow MFP you set your calorie goal to a lower number and then you eat back all of the calories you burn with exercise. So at the end of the day you want your NET calories to equal your goal. If your goal is 1500 and you burn 500 at the gym, you would eat 2000 total.

The people talking about taking off a percentage are using the TDEE method. That means you manually set your MFP calorie goal higher and DO NOT eat back your exercise calories. So if you figure your TDEE (total number of calories burned in a day) is 2434, then you take 20% off of that, which @Lissa_Kaye says is 1947 and I'll trust her math. You set your MFP goal to 1947 and just eat that amount every day regardless of exercise.

Both sides have pros and cons. With MFP's method you might find yourself encouraged to exercise in order to get more food, but rest days will suck because you won't be able to eat as much. With TDEE method you don't have all those ups and downs in calorie allowance but if you don't exercise as much as you told the calculator you would then you won't lose as much weight as you planned.

runfoorun

An easy way to do it is to estimate how many calories you burn each day, which is easy to do if you pretty much do the same workout daily. So assume you burn 600-800 calories a day with your 1 hour of cardio and strength training. So set your daily calorie goal somewhere between 1800-2000 so you can hit that "Net" goal of 1200 ish.

brianpperkins

khristiana wrote: »

Ok... I did your calculations from above and got a BMR of 2069. MFP BMR calculator says 2043.

My front page says the following: Goal: 1200 Food: 688 Exercise -391 = 297 NET

What exactly does NET mean? Am I to eat an additional 297 calories?

NET is your caloric goal using MFP's Non-Exercise Activity Thermogensis (NEAT) calorie counting system where you are expected to eat back your exercise calories in order to maintain the built in deficit.

Assuming your numbers are accurate ... 688 is way too low of a daily intake. You then burned off nearly 400 calories meaning you provided your body with a net of under 300 calories of fuel for the day. Basically when your net is that low you are setting yourself up for health issues as the body starts looking within for nutrients to keep vital organs functioning ... you'll burn some fat, muscle mass, eventually you'll see mineral depletion from your bones, functions such as keeping your hair and nails growing healthily cease so you lose hair, etc.

khristiana

Ok cool... Thanks everyone!

khristiana