Can someone clever explain this? (Calories and maths)

[RoryGlory]

Going by the table below I need -410 calories a day to get to my goal.

If my resting metabolic rate is (I believe) 1800

So if I eat 1200 calories a day I have a deficit of 600.

So 1200 - 600 = 600

So to get to -410 ... I would need to burn a further 1010 calories? Is that right?

That's only a 200 calorie deficit though

How did you burn that many calories today OP?

OP wil not lose 4.5lbs per week by burning off 1600 calories while eating 1200 calories. It is only a 400 calorie deficit per day so the maths do not make sense

You're doing the wrong maths @dementedpixie

Your maths implies a BMR of 1600, consuming 1200 and no extra exercise. That gives a deficit of 400. That's not what we're talking about.

OP is trying to consume -410 calories per day. Which is the same thing as saying you need to expend an extra 410 calories per day more than you eat. So if you eat nothing, you need to burn 410 calories. If you eat 1200 calories, you need to burn 1610 calories to get back to that -410 position. This is through additional exercise, not through just living and breathing and sitting around because the calculator has already allowed for that.

So how many calories in total should she aim to burn each day?

Because if you mean over and above the maintenance rate then why is it wrong to add the 2 figures together to give the 3410 we have been saying

It isn’t that simple. If you severely restrict calories your body will reduce your metabolism so you burn less energy. You’ll just feel tired instead of losing weight. On the other hand, if you eat loads or exercise loads your body can actually boost your metabolism and burn more energy.

So to put it another way:

The required deficit is:
1800 - -410
=1800 + 410
= 2210

Of that 2210, she will achieve part of the deficit through eating less:
1800 - 1200 = 600 deficit

The remainder of the deficit will need to be achieved through exercise:
2210 - 600 = 1610

I.e. the amount of calories she's eating plus 410.

@BizzzzyBee I absolutely agree. This has to be up there with the most deluded weight loss plans. It sounds like a great way to mess yourself up.

1lb of fat weighs the same as 1lb of muscle
But it will be a smaller volume because muscle is denser. If you’re muscular you’ll be thinner than someone the exact same weight who is composed of fat.

You have set yourself an unrealistic target. That's what it means.

But you are still saying an extra 1610 needs to be burned off on top of what her body naturally uses each day. She would not be aiming to just burn off 1610 calories in total

In case anyone's interested in how the calculator arrived at these silly figures all it's done is this:

28lb weight loss x approx 3500 calorie deficit required per lb = 98000 deficit required

Divide by OP's 44 day target: 98000 / 44 = 2227 - round to 2210 as they must have used numbers to different decimal places or whatever

Then it's subtracted that from her BMR:

1800 - 2210 = -410

It's an extremely rough and ready calculator with absolutely no functionality built in as to whether it's actually possible (spoiler: it's not).

@dementedpixie she wanted to know how many extra calories she needed o burn off. That was literally what the question was. You don't have to set out to try and burn off your BMR - it just happens by virtue of being alive.

Though you seem to think you know better, so how about you come back in the middle of October and tell us how your attempt to lose 2 stone in 6 weeks went.

Ok, so you gave the extra calories and others (including me) gave the total calories. We weren't wrong , we we just answering a different question

Just read this and it made me wonder about my own weight loss..I lost 1st 11lb in 6 weeks. I didn't do any exercise (sw) so why wouldn't 2st be possible (I was only 3lb off that myself?) I don't understand the numbers but If I regulary lost 3.5lb a week (first week was a much bigger loss), surely if you need 3500 deficit a week for a 1lb lost I would of had 12,250 deficit when I lost 3.5lb? How is that even possible? I am done losing weight now but my current maintaining calories (according to mfp) is 12880 for the week? So surely it wouldn't of been that much higher when I was losing weight to be a 12250 deficit?

I’ve dieted till I’m literally starving and can’t lose any weight because of breastfeeding hormones. Your body contains numerous hormones and it has several survival tricks to hang onto fat stores. It isn’t a mathematical equation, that’s a very naive view of weight loss. All you’re going to do is reduce your metabolism so when you eventually start eating normally again you’ll pack the pounds on.

All you’re going to do is reduce your metabolism so when you eventually start eating normally again you’ll pack the pounds on

Why would I?

I’ve always found this notion odd. If you reach your goal weight and then stick at your maintenance calories then you should stay the same.

People only gain weight after ANY diet if they eat above the maintenance level.

Surprised you didn’t say I’d be in starvation mode.

Because your BMR also depends on your % muscle.

Muscle not only looks better on your body, it takes more energy to maintain. If you trash your body with this 'diet' amd lose loads of muscle, your maintenance cals could be 1200 not 1500,leaving you on a diet for the rest of your life.

Or taking your calories back up to 2000 as you try to regain muscle... You'll always gain fat at the same time, so rinse and repeat indefinitely?

Thanks Hobby I thought I was going to have to do a spreadsheet

PPs have confused calorie deficit with net calorie intake, it took me a while to work it out tbh because it sounded convincing!

@RoryGlory have a look at Michael Mosley's Fast 800/Blood Sugar Diet.

There's lots of info and knowledgeable folk on the boards here on MN, sounds like it's pretty much what you're looking for

Blood sugar diet and fast800 thread 16 www.mumsnet.com/Talk/fasting_diet/3671814-blood-sugar-diet-and-fast800-thread-16

You can eat real food, and lose weight on our blood sugar diet thread. Keep up your weight bearing exercise and cardio, and eat 800-1000 (or more) calories of the right foods.

I might save this thread. It baffled me so much last night I fell asleep in seconds