keeping up metabolism and losing 5 lbs a week?

First, 1200 calories a day is the suggested net intake on MFP - not gross dietary calories eaten. You may already know that but many people new here are confused by the site's presentation of information and lack of clarity.

Honestly, there simply aren't many studies that have been done on massive caloric deficits (50% or below) and the effect on energy expenditure. Thus, there is really no way to accurately measure the degree of decline in energy expenditure or your Resting Metabolic Rate after two months at such a deficit. The famous Minnesota Experiment lasted six months and the men experienced a 40% decline in energy expenditure. Even given that example, you can't even estimate what that would mean for you because you are a woman and would be assuming a much larger deficit...

One thing you can likely count on, if you assume that large of a deficit, is: depressed Resting Metabolic Rate, reduced leptin levels, increased cortisol levels, and a likelihood of reduction in RMR due to loss of muscle mass.

Also, the vast majority of that 5 lb weight loss will come from water weight with some muscle loss, not true fat loss. This is especially true if you have been dieting or sustaining a caloric deficit for some time.

hi everyone, i got a fitbit and have been researching and trying to understand it all quite a bit. I concluded that I can eat 1200 calories a day and burn 1200 calories a day and end up with a deficit of 2410 (my BMR) a day for an approx loss of 5lbs a week. Now I know many people say to not eat below your BMR but I am trying hard to lose 5 lbs a week before my beach vacation in October. (So only about 5 weeks of doing this) Could I do this plan for the next month and a half and then go back to trying to lose 2 lbs a week or will my metabolism be screwed up? Will staying at 1200 calories a day be the key to keeping my metabolism up or will I ruin it? Thanks for your help!

You're joking right? 2410 deficit. Very bad idea. Hair loss, muscle loss, bone loss, fatigue, exhaustion, dehydration, maybe even a bonus trip to the hospital. It's unhealthy and dangerous...and quite honestly moronic.

So you are going to try and live on 0 calories for 5 weeks? :noway:

If you need to lose 5 lbs a week the only thing I can suggest is liposuction or amputation.

Forget metabolism worries, this kind of diet will put you in hospital. I seriously advise against it. Aim for 2 lbs a week max.

but what about me ?

Good question, we don't know anything about you. If you were obese you could run a deficit of 1200+ calories per day but that needs 40 lbs of excess fat to fuel it. Is that you ?

A deficit of 10 - 15% is a gradual weight loss and easier to manage, but it does mean a long wait if you have a lot to lose. So starting with a larger deficit and tapering off is usually recommended.

Thanks so much for your answers (especially geekyjock.) That makes a lot of sense. I didn't realize I should be netting a minimum of 1200. You are right, there are a lot of things on here that are not clear but that does clear it up. Sounds like you have done your research! And it sounds like that extra few pounds won't be worth it to lose quickly.

Lizziebeth, no I wasn't "joking." The extreme weight loss show gives the extremely obese a caloric deficit of 3500 a day and they lose a pound a week, so in my mind it was possible to do slightly less for a slightly smaller person. I think there are a lot of people who don't understand the specifics of how to lose weight the "right way." I certainly am one of them. If there was a clear cut answer, I wouldn't have struggled with my weight my entire life.

The big question here.... what is the maximum deficit that would be healthy? I know they say 1000 a day for a 2 pound a week loss as an overall, but this applies to people of all weights. If people on the weightloss show who weight 350+ can deficit 3500 a day (from a licensed nutritionalist and fitness coach) and seem to be pretty healthy, what can someone who weighs 250ish deficit? It seems like a fair assumption that the bigger you are, the bigger you can expect to lose each week or the more you of a calorie deficit you can give yourself. People who don't have much to lose need to stick to 2 lbs a week... but what about me?

The contestants on extreme weight loss shows are closely monitored by Doctors. 2 pounds of week is the maximum recommended for healthy weight loss and this number is not for people who don't have a lot to lose (in fact people who only have a few pounds to lose it's only recommended 1/2lb to 1lb).

Still a bad idea. Not even close to healthy OR safe.

You are really willing to risk your health for some vanity outing in a swimsuit?

Burning that much could cause you to be sick, weak, faint, and such.

*facepalm*

This is really a better question to ask a doctor, rather than a group on the Internet. A professional who knows your complete health history can go a lot further to help you plan a diet/exercise regime, and may be able to advise you on how much you can expect to lose per week. Keep in mind that not all weeks will be the same!

MFP is full of a lot of people with a lot of different health and fitness philosophies. I find it more confusing than helpful to try and sort out the truth in all the vastly different ideas here. It's definitely cool to see so many approaches, just not something I'd recommend to build one coherent plan.

You say you're looking to lose 5 lbs weekly. How about you not focus on the scale & just really focus on exercise. Inches are more noticeable than the # on the scale.

How heavy are you? Because my BMR is like 2500 (i eat between 1200-1500 a day) so if I ate 0 cals id barely lose 4 pounds. Cmon smarten up a bit.


edit: And eating back calories is the most counter productive thing if you are trying to lose weight (NOT bodybuilding). You might as well not exercise.

MFP confused me with the net and deficit thing already built in too, so I read a suggestion somewhere that has helped me, at least visually. It probably wont be great for most because it requires a little math

I take out the deficit - i over write whatever MFP says with 500 more or whatever I calculate my normal base calorie expenditure actually is (I ended up with 1500 since I am pretty sedentary - but trying!). It will increase that as I exercise, but whatever is showing is approximately what I *really* am burning. Usually it ends up around 1900 by the end of the day, so I am eating between 1300-1400 most days, more if I exercise a lot, less if I dont (which really is about how it should be?)

Then I just aim to finish out the day at 500 less than that. I dont think of it as "eating my exercise calories", although that is what it is. I just know I want to eat 500 less per day than I burn, so I lose about a pound a week. If you want to lose 2 pounds a week, aim to finish out the day 1000 less than your allowance. It is just much more upfront this way for me than thinking about that hidden thing going on.

It also helps because I know that on my "bad" days, I can go ALL the way up to the total shown and not "blow it" since that is my maintenance calories - what I need to stay right where I am. A day here and there of ending up almost at my allowance wont hurt me one bit other than slow down weight loss. But no gaining if I dont go over. Makes me much less hard on myself.

Agree with the others - make it something you can sustain, not something you want to accomplish all at once. Try to lose 10 pounds over the next 5 weeks and then celebrate on your vacation knowing that you have the system figured out now and next year you will be way beyond that initial 25 you wanted. Honestly, at over 200 pounds even with losing 25 pounds quickly - you wont notice enough of a change in your body to be worth the risk! Get a good shaping suit and enjoy yourself healthily! (is that a word?!)