Is eating 4% below BMR really that bad?

I understand that if you use "sedentary tdee" that I need to eat back exercise calories.
But you said that you shouldn't eat at 20% deficit if you are sedentary and not exercising.
My question was why would these calculators even give you a tdee-20% calculation for sedentary, if you shouldn't do that much of a deficit? It doesn't make sense to me that they are just "assuming" that I will exercise on top of that number. If they wanted me to exercise, then sedentary shouldn't even be an option. Do you know what I'm saying?

I want to point out that I'm not arguing with any of the advice being given here. But I see a lot of advice thrown around without an explanation behind it. If I am going to follow the advice of someone - I want to understand the reasoning behind why I should be doing something.

The calculators give you a TDEE-20% calculation for sedentary because they assume you will be adding exercise calories on top of the number that you get.

I personally set my calorie goal to about TDEE - 20% for sedentary. I add exercise calories back on top of that.

If I did no exercise, I would not set my calorie goal to TDEE - 20% for sedentary.

The reason I recommend not doing that is because eating a significant calorie deficit while doing no exercise is a recipe for muscle loss, poor cardiovascular health, fat maintenance, fatigue, and general feelings of tiredness and lethargy.

Ok, I understand what you are saying.
So basically, to answer my original question - since I am not currently exercising, I should not use TDEE - 20%.
I should use a lower deficit for now.

If I begin exercising, I can increase the deficit to 20% and it would be ok to be slightly under my BMR.

Correct?

Yes, that would be my recommendation.

Ok makes sense.

How accurate do you think the TDEE calculators are that don't include body fat (since I don't have a caliper to measure body fat). ?

They seem to be really good for normal people actually. Pretty much everyone I know that followed them lost weight at expected speed.

Good to know!

So problem now is, you say its ok to be a little below BMR (if i'm exercising) because it isn't a magical number and I should be more concerned about the size of my deficit.

Yet others here say the BMR is what you need in a coma and you should never, ever eat below it.

So who is right?

The only importance BMR has is that it's the starting point for calculating TDEE. That's it.

There's nothing at all magical about BMR once you have TDEE. The only numbers that matter are the actual number of calories you've burned in a day - your TDEE - and the actual number of calories consumed.

The arguments for "never eat below your BMR ever" are nonsensical. They often resort to ridiculous car analogies or try to scare you with "eating fewer calories than you need to stay alive!" This doesn't make any sense. The entire point is to eat fewer calories than you need to stay alive so that your body taps into its fat reserves to make up the rest.

Also, you may have already said this and I just forget.. if I'm not exercising - what deficit would you recommend for now? 15%? 10%? (I have 41 lbs to lose)

My recommendation would be to exercise, even if that meant half an hour of jumping jacks and lunges in the living room 3 times a week.

I know that's not the answer you want, but honestly I wouldn't recommend anyone try to lose weight without any exercise unless they were literally so fat they could not do any.

Starting out, I can't lift more than 3 lbs - my arms feel like they are going to fall off after a few times.

I did not exercise at all to lose the 40 lbs.

These facts are probably related.

Starting out, I can't lift more than 3 lbs - my arms feel like they are going to fall off after a few times.

I did not exercise at all to lose the 40 lbs.

These facts are probably related.

Yes obviously but you have to start somewhere. If all I can do for now is 3 lbs, isn't that better than doing nothing, and just maintaing my weight, when I still have 40 lbs to lose?

Well, you can do more than 3 lbs, even if you don't think you can. Presumably you can, say, open a car door, yes?

How about a gallon of milk? Can you lift a gallon of milk?

Opening a car door requires more than 3 pounds of force. A gallon of milk weighs almost 9 pounds.

Women always underestimate how much they can lift. I don't know why. They just view themselves as inordinately weak.

So why can't you do any calisthenics or anything in your house? Do you have some physical limitation that you can't do some lunges or something?

I tested out the dumbells in the store and I could barely lift more than 3 lbs. Yes, I can pick up a gallon of milk. Can I do 45 bicep curls with it? No, I can't. I bought the heaviest ones that I could.

I had an injury and for now, all I can do is light upper body.

Doing 45 bicep curls with anything is one of the biggest wastes of time possible.

Look, you need to exercise in some fashion. You seem unwilling to do so. I'm not going to spend all day fighting your excuses.

Best of luck to you.