Eating under BMR?

hj1119

I'm a 5'10ish female, 32 yo, currently 163 lbs - 32%ish body fat. I met with a consultant over the weekend to have my BMR tested. She is not a certified dietician, but according to her has "all the education but none of the credentials."

Anyway, I "blew" a 1454.

She then proceeded to put my stats into her handy dandy calculator. Even though I am on a plan that is kind of working for me, I humored her. I told her I work a desk job so she selected sedentary. I told her I walk the dogs daily, aim for 10K steps on my fitbit, and run 3 miles, 3X a week. She dismissed all of that activity and told me "anything I did was a bonus" but that according to her spiffy dietician tools, I should aim for 1398 calories a day to lose weight.

I am confused - I thought it was strongly advised against to eat less than your BMR?

WalkingAlong

No, that's a forum myth.

willrun4bagels

This is worth a read: http://www.myfitnesspal.com/topics/show/1058378-oh-noes-i-am-eating-below-my-bmr?hl=oh+noes&page=1

That being said, what are your goals? Given your stats, I'm quite sure you could eat more than 1398 cals a day and still lose weight (albeit, slowly, but depending on what your goal is, your weight loss should be slower as you're closer to goal).

michikade

I'd be a little skeptical in regards to "exercise is a bonus" but there are two schools of thought:

1) eat more than BMR
2) eat no less than 1200 calories

These aren't mutually exclusive (won't have many people advocating less than 1200 calories regardless of which one they believe without being under the supervision of a doctor).

Now, if she's saying that you should eat 1398 NET calories (and eat back exercise) then it really comes out in the wash that way with your BMR what was determined - assuming that's right - because each day that you exercise you'd actually eat quite a bit more, whereas days when you rest you eat a bit less.

I've been doing the math and for me personally, it's two means to get to the same end --- with TDEE - 20% I don't eat back exercise, so on days when I exercise I net lower than on rest days but eat about the same amount everyday calorie wise, whereas before I was eating less when I rested and more when I exercised. It's still the same weekly deficit FOR ME PERSONALLY (your mileage may vary).

MinnieInMaine

It's not THAT far below your BMR so I wouldn't worry about it. There are a couple of custom goal settings on here that suggest calculating based on goal weight and that would probably give you about the same result. If she said to eat a few hundred under your BMR, I'd be concerned but 50 calories is nothing in the grand scheme of things.

However, I disagree with her suggestion not to eat calories back. I'd eat back at least half... I don't know about you but if I don't, I"m starving, especially on days after a good run.

Mischievous_Rascal

That sounds like a pretty high deficit. What is your goal? You could probably eat a little more and still lose in a slow and steady manner. However, if you exercise, you should definitely be fueling that and eating those calories back. And truly, if you're hitting 10K+ steps a day, that is FAR from sedentary.

There's a reason to see an accredited dietitian for these things. if she really had all of the education, she would have the degree to go with it, not just a handy dandy little "tool". That only makes sense, yes?

levitateme

It's not the worst thing in the world to eat under your BMR, but it's not necessary.

Although you are much taller than I am, we have similar stats. I'm 5'4", 31, 159 lbs, 29.1% BF and I am achieving a slow recomp eating about 2500 calories per day (sometimes more). You are very active, there's no reason to eat so little.

ukaryote

That is not a big deficit. 1454 BMR - 1398 suggested = 56 cal deficit. Think 1/6 of a Bruggers Bagel each day.

yarwell

So your resting metabolic rate is about 1400 and you were advised to eat about 1400. Your deficit therefore comes mainly from activity and digesting food so is going to be 300 - 800 or so depending how active on a given day.

RHachicho

Eating a little below your BMR will in most cases produce no ill effects. Honestly we really can't handhold you here. Every life is different. Our habits both nutritionally and activity wise play a huge role in determining what constitutes a wise calorie level.

Personally with me I am very active. So if my diet was to become too restrictive it would show immediately on my exercise.

It depends how fast you want to lose I guess. You could go a bit higher. But then you would lose slower.

lemurcat12

It looks like what the consultant is doing is taking your BMR and multiplying by the sedentary multiplier and then subtracting 500 calories to get what you'd need to lose 1 lb/week without exercise. Then if you exercise on top of that you'd lose more than 1 lb a week.

On the whole, I think this is a reasonable approach--before I discovered MFP I generally thought of weight loss as working that way--subtract about 500 from maintenance calories and then try to add exercise to lose more. MFP has "eat back exercise," but that's in large part because people tend to go for a 2 lb deficit and MFP sets you up to do it with just calorie cutting, which leads to a higher deficit than works for many and, of course, more than the recommended 1-2 lb/week if one also exercises on top of it.

So in theory if you just went for a 1 lb deficit goal, there would be less reason to eat back exercise.

This is assuming you'd want to aim at more than 1 lb/week, which you might not given that you are already a healthy weight. That's a separate issue to the more general question of whether you should always eat back exercise. I keep seeing people say that their trainers/doctors are against eating back exercise, but it really depends on how the deficit is built in the first place, IMO.

As for BMR, I've never understood why it is supposed to matter one bit whether you are below BMR if the deficit is otherwise reasonable (which it quite easily could be). That's something I've seen only at MFP. I suppose it can be a rough way of checking if a deficit is reasonable for people who are not sedentary, but I don't worry about it (I am currently eating more than my estimated BMR because I'm trying to be active, but when I started I didn't).