How far below you BMR can you go or do you always need to meet it?

There is no need to eat at or above your BMR estimate, especially when obese.

While I don't have an answer to your question directly, I will say that it's a bigger deal if you sustain it for very long periods of times.

So going crazy low for a week or a month might not be a big deal, going unnecessarily low for a year could lead to problems.

The only way you're going to lose weight is to eat less than your body needs to run.
The BMR is the minimum your body needs to function, if you're lying in a hospital bed in a coma all day.
If you're 500 under, but feeling & functioning OK, it's probably OK.
Since you have lots of energy reserves you won't feel the effect as much as someone who's at the low end of a healthy BMI range & undereats the same amount.

When I started working on losing weight last year, my BMR was 1974 & my goal calories were 1700.
My current BMR is 1636 and my calorie goal is 1400.
(Those are TOTAL calories, not net. Ignore net / exercise.)
My doctors are all quite happy with my progress & health.

At 445 lb you're probably eating 4450 cal/day to maintain weight.
Cut 1000 cal/day from that and you should lose 2 lb/week.
If you're not losing, drop another 100 calories & wait a couple weeks. Repeat until you see results.
When you hit a plateau, drop another 50-100 cal & wait to see results.
Keep doing that until you get to a calorie level which is 10x your healthy goal weight (look at a BMI chart, aim for the top of the green range for starters; you can adjust lower once you get there & see how you feel/look).

shadow2soul wrote: »

MKEgal wrote: »

Keep doing that until you get to a calorie level which is 10x your healthy goal weight

Seems like really bad advice to be just giving out to everyone. I understand that this is what your doctor told you and it works for you, but lets think about it.

Your saying a 4'10 person with a goal of 98lbs should only eat 980 calories per day regardless of activity level.

Your advice, in my case would give me a deficit of around 1300 calories per day or even more if I decide I want to go a bit lower. So almost 2.5lbs per week loss. I'm not obese. Only overweight. This kind of deficit wouldn't be healthy for someone like me. If I decided I wanted a bmi of 19, then my goal would be less than 1200 calories according to your advice.

I'm not trying to be mean, but what your doctor told you isn't really one size fits all.

I've pointed this out a few times with no response. My healthy goal weight might well be 115 (I don't have a firm goal), and I train hard--was doing half marathon training until recently, multiple hour bike rides, etc. As a result, I was losing 1-2 lb/week when consistently eating 1700 (this seems to have stalled, although I suspect it's more that I was eating too much during the holidays and not logging well), suggesting a TDEE of over 2200 (with only 15 lbs left to get to 115). And yet I should eat 1150 and not anything more to account for a 2 hour run? Hmm, seems like a bad idea.

I also find the assumption that people don't exercise enough for it to matter and undercount calories problematic. When I first started (and was obese) I consistently lost substantially MORE than MFP and the calculators predicted, which suggests that I may have been overcounting (I think this is not uncommon when starting out for certain kinds of personalities) or underestimating exercise.

I think it's great MKE's doctor knows her and was able to come up with good advice for her, but it would have been terrible advice for me--and that's for the best, since I'm not the patient and no information about me has been collected. (My own doctor said "keep doing what you have been," but certainly did not suggest that my calories should be dictated by goal weight. She asked what my calories were--at the time 1600-1700--and said that sounds good, even though I was 145 or less at the time.