Okay, so we all pretty much know that if we don't eat enough calories, we'll invoke the body's starvation response i.e. the # of calories we have ate are way below maintainence level.

But wait. If you're eating at maintainence level, will creating a HUGE calorie deficit via excercise cause your body to go into starvation mode????

Thanks in advance!

From examples I have read - basically yes. You will tend to burn more muscle that you would otherwise and retain fat. In order to do this, while in a severe calorie deficit, your metabolism will slow.

This is one way of getting skinny fat - it make take quite a bit of time if you have decent muscle mass to start with (or a lot of fat).

I think I remember Berardi giving an example of an athelete who could not get her BF down untill she started eating more.

Now there are ways of keeping your metabolism higher that it might otherwise be for a certain calorie deficit - lots of veggies, protein (?), fish oil/right fat ballance etc..

As with many things, more is not always better. This is why 1-2lb/week is a generally recommended 'safe' rate of weight loss. Obviously if someone is very obese (or already lean) these numbers are less applicable.

Thanks for the reply NEdge. Unfortunately, now I'm more confused. If you don't mind, could you help me clear this enigma?

So, a severe calorie deficit whether it comes from eating too little or burning way too many calories from hardcore excercise causes the starvation response----which causes your body to become very ineffective in spending bodyfat as energy. Thus, we have to carefully ensure we eat enough calories to make sure the deficit is "small" enough for our bodies to forgive.

Now, this might sound like a really trivial followup question, but why then is excercise necessary at all? Let's assume our goal here is purely to shed bodyfat, and we don't care about lean body mass.

I mean, in the end, it's a NET-calorie-deficit that determines how much bodyfat you lose right? Sure, having more lean mass increases Basal Metabolic Rate (BMR), but doesn't that only make a person burn more calories throughout the day? If you're burning more calories throughout the day by resting, then you're more likely to create a bigger calorie deficit----which we'll have to compensate by eating more to reduce the severity of the deficit.

What's the point of excercise then---in other words, why even bother increasing our BMR's??? We could create the same deficit at the end of the day simply by eating just the right amount of food.

That depends on your goal...You train because bigger muscles look better. I´m sure that you could lose fat with the right diet even if you didn´t train at all. It´s really a fitness issue. Fat loss is not everything if your goal is to look as good as possible. Or if you want to be fit and healthy.

Personally, I don't believe there is such a thing as a starvation mode unless you are TRULY STARVING, i.e. not eating any food.

It's a hyped up overblown phrase people use to justify eating more calories and not going low calorie to cut.

There IS homeostasis ... the body tries to stay the same. You lower your calories, your metabolism will slow. This isn't starvation. This is simply an adaptation mechanism. It's not healthy. Research suggests it could even extend your lifespan. It's more related to calories.

Starvation is a complex topic. Many people who eat well over maintenance calories are starving in one sense, because they are getting almost no nutrition. They eat a lot of fried and processed foods that have little nutritional value, and the body starves from lack of proper nutrients. This is serious and leads to degenerative disease over time.

On the other hand, some people might eat well below what the equations call maintenance and do fine because they are packed with nutrients, etc.

Then there's the question of WHAT IS maintenance? If I've eaten low calorie for a long time, my metabolism is slower than what the equations would suggest. In other words, I'm no longer eating below maintenance because my maintenance IS by definition the lower calories. Again, it's not starvation, it's just having a slow metabolism.

So I think short of fasting for days, the concept of starvation mode has to be thrown out the window or only applied to extreme cases where perhaps you slash calories in half or are on some restricted program that seriously limits your nutrients.

Jeremy

Okay, so we all pretty much know that if we don't eat enough calories, we'll invoke the body's starvation response i.e. the # of calories we have ate are way below maintainence level.

But wait. If you're eating at maintainence level, will creating a HUGE calorie deficit via excercise cause your body to go into starvation mode????

Thanks in advance!

Jeremy, you're my absolute hero, with this response and the response to the target heart-rate thread. I've always been of the opinion that our bodies aren't such delicate machines that we have to stay precisely within a set number of calories or an exact heart rate in order to avoid all our muscles breaking down immediately.

I agree with everything Jeremy posted. But I would argue that if you go too low for your current state you will not necessarily get the optimum body composition results. I think this is particularly true with most people's diets, even if they think they are really 'clean'. Of course this may not really be 'starvation mode' - I guess I'm not even entirely clear what that means - just that you will tend to loose/burn muscle rather than fat is the way I think of it rather than metabolism 'crashing'.

For instance if you are say training by running 15 miles/day and eating 2000kcal, I dont think you are going to easily get ripped.

But, that does not mean that there is a set calorie limit which 'starvation mode' or muscle loss will kick in. As Jeremy said, as you reduce calories, your maintanance will change. If you stick to say 500kcal below maintance, you may well be able to get ripped while eating 1000kcal.

Most of us just dont want to eat that little - I can't keep that up simply because of family commitments for instance. So when I cut, I refeed or increase calories for a while to get maintanance level up before cutting again. It takes longer but is less painful and more doable from a social standpoint.

Still, when Jeremy was cutting I'd be surprised if he was loosing more than 1lb/week at 8% or below without also loosing quite a bit of muscle. What calorie level he was on is not as relevant in my mind. Especially as he knows his body and was certainly feeding it enough of the right foods for it to 'feel' fed at a low calorie level. I think what most people run into is they reduce calories by a lot, but do not have their nutrition absolutely 'wired'. Then wonder why they loose muscle instead of fat or go wild on cheat days and get fatter and claim starvation mode.

Our bodies are very adaptive, more than most would lead you to believe. I have certainly done 'unorthodox' things that have been very successful, but they may not work for everyone and for the 2-3 weeks I did this my diet was absolutely spot on. I can't tell you what 'spot on' would be for you or anyone else, but adaptation to change can be quite remarkable.

If you're eating at maintainence level, will creating a HUGE calorie deficit via excercise cause your body to go into starvation mode????

That's a contradiction in terms. "Eating at maintenance" means, by definition, eating neither a surplus nor a deficit of calories. It means that the calories you are eating matches the calories you are burning (through exercise and metabolic processes).

My opinion, culled from everything I have seen and read - and from thinking about it logically - is that what people call the "starvation mode" is more often than not simply the body slowing down because of the deficit. If this happens to a large degree, then it gets to be a vicious circle in which you don't have the energy to exercise properly, and everything you do is more sluggish. So you burn fewer calories and the deficit is now reduced. Over a long enough time, the poor exercise performance could also lead to a loss of fitness and a slowing of the metabolism - which further reduces the deficit and also makes it more arduous to exercise. If you then try to resume the weight loss by eating less, you'll slow down even more and hence burn even fewer calories (and hence have even less of a deficit and slower weight-loss).

I don't think this is usually true "starvation" - the things that happen in concentration camps or during hunger strikes is another thing altogether.

I also happen to think that if you increase your food intake and increase your exercise by the same number of calories, although this doesn't significantly affect weight loss it is still an advantage. If you eat more, then you have an opportunity to get more vitamins, fibre, minerals, antioxidants, etc. In fact, for me, this is one of the most important functions of cardio: to increase the amount of calories you burn each day, so that you can increase your food intake by the same number of calories and therefore get more micronutrients and fibre :) (Not to mention that if you are like me, eating is actually enjoyable as well.)

Thank you all for replying. I appreciate it!!! You guys made me realize that I had my definitions all screwed up, and my initial question was pretty much nonsense........sorta like "how do you chew water?"

I was so caught up in estimating my maintainence level in calories by using the Katch-Mcardle formula/physical activity multiplier (a la BFFM chapter 6) that I forgot that one's maintainence level itself depends on how much excercise one does.

I was so caught up in estimating my maintainence level in calories by using the Katch-Mcardle formula/physical activity multiplier (a la BFFM chapter 6) that I forgot that one's maintainence level itself depends on how much excercise one does.

The way I look at it, there is only one possible way to determine how many calories you have to eat to achieve maintenance (= equality between calories in and out, = zero net weight gain/loss). And that one possible method is trial and error - observation. If your weight is increasing, you know you are consuming a surplus. If your weight is decreasing, you know you are consuming a deficit. Between the two, when your weight is stable, you know you are at maintenance. To achieve the desired state, you have to observe the trend in weight change, and if necessary, increase or decrease the gap between calories in and out.

The formulas give you a helpful starting point to kick the process off. When you're just starting, you need an initial amount of food to try eating, and the formulas, being based on average populations, are a reasonable place to start in the trial and error process. They show you a good place to start on the map.

From all the information I gathered through various articles, your body is more apt to dispose of more fat when burning calories through exercise, as opposed to the same amount of calories being cut in the form of food. Also, your body burns more subcutaneous fat rather than visceral this way. So I've read. Now, I love science, but first hand experience is what convinces me most times.

For me, when I just cut calories and do not exercise at all or very scarcely, it feels as though I'm a deflating marshmallow. Specifically, I do not lose INCHES. Whereas when exercising an adequate amount, say at least 45 minutes a day, I not only lose inches, but it actually feels like my fat is shedding off my body. Like my skin is getting tighter and thinner. Actually, it's like I lose from the inside out through diet, and the outside in through exercise.

That's what happens with me anyway. I think starvation mode is overblown as well, something that takes weeks or months to set in ( I have no personal experience with that though) but I believe you can slow your metabolism down by either too much physical exertion or through starvation from inadequate calorie intake. Either way your body is not getting enough nutrition.

philph: no doubt. i'll be taking data periodically and careful analysis will follow.

naturegirl: i can corroborate both the "marshmellow" and "shedding" feelings. i really don't know if it's just our mind's biased perception of accomplishment, but i really feel as if my body has lost fat the morning after a great workout.

John Berardi has argued that what adding exercise brings to your nutrition efforts is a "nutrient partitioning" effect, essentially, it makes your body more efficient at processing nutrients and using them in the most desirable manner. Depending on the time, type, and amount of exercise, these effects can occur over a short window of time during the day or in a more general, quasi-permanent sense. Read up over at his website--it's pretty interesting stuff.

And I totally agree with philiph--invoking the "starvation response" idea is usually just a convenient way of talking about a slowed-down metabolism.

Great thread! Naturegirl I appreciate very much how you put it.
Like GreaseVeteran, I also feel the "marshmallow" and "shedding" sensations.
Or at least, those are some of the best words I have seen yet,
that capture what I think I am sensing.

I just wanted to share a little about fasting.
I did a 24+-hour fast not too long ago. I hadn't fasted like that in years.
I haven't truly fasted more than several times in my life.
It was an enlightening experience. Or, an experience with much opportunity for enlightenment.
I might equate it to what a career couch potato feels after his first week of workouts.
But I knew, after doing it, just knew, that I did not want to fast often.
But still, I'm going to do it again on New Year's Eve.
Then, probably, not do it again during 2006.

It's wrongly termed the stravation response. The deal is metabolism is a dynamic system and input affects output. When you drop calories your metabolism will slow down to a degree. This is true even with a healthy deficit. But it's unavoidable and necessary. But if you drop calories excessively, your metabolism can slow down so much that you're not eating at a caloric deficit anymore. Fat loss will stop. It's a protective mechanism. If your calories are too low, your body slows metabolism a lot so that you don't starve to death. That's probably how it got its name. How low is too low is different for everyone, and it's also impacted by training, what you eat, and nutrient timing. But the take-home message is that lower is not always better. Sometimes upping the calories a little bit and help bust through a plateau whereas further dropping would actually be counterproductive.

Great thread! Naturegirl I appreciate very much how you put it.
Like GreaseVeteran, I also feel the "marshmallow" and "shedding" sensations.
Or at least, those are some of the best words I have seen yet,
that capture what I think I am sensing.

I just wanted to share a little about fasting.
I did a 24+-hour fast not too long ago. I hadn't fasted like that in years.
I haven't truly fasted more than several times in my life.
It was an enlightening experience. Or, an experience with much opportunity for enlightenment.
I might equate it to what a career couch potato feels after his first week of workouts.
But I knew, after doing it, just knew, that I did not want to fast often.
But still, I'm going to do it again on New Year's Eve.
Then, probably, not do it again during 2006.

Any reason why New Year's Eve is the day you're choosing to do it?

Any reason why New Year's Eve is the day you're choosing to do it?

Purely a personal reason:
I want to celebrate what discipline I've acquired in 2005, with...more discipline.
The fast I did recently gave me an unexpectedly strong inner reassurance,
like a confirmation of faith in self - a feeling of "hey, I AM in control here."
I didn't expect that, really - but it was something I can see needing to nurture,
now and again, but only once every great while.

Really, it's not that I have any kind of bad history of partying too hard,
I just don't want to party after the prevailing tradition. I want to party my way:
Light exercise on Dec 31. But only water. No eating.
(I have a history of overeating. I really kicked that out of my life in 2005.)
I'll probably eat just a lump of cheese at midnight, to break the fast, then, go to bed.
And not work out on New Year's Day, going back to normal eating then. Then, back to workouts Jan 2.

Purely a personal reason:
I want to celebrate what discipline I've acquired in 2005, with...more discipline.
The fast I did recently gave me an unexpectedly strong inner reassurance,
like a confirmation of faith in self - a feeling of "hey, I AM in control here."
I didn't expect that, really - but it was something I can see needing to nurture,
now and again, but only once every great while.

Really, it's not that I have any kind of bad history of partying too hard,
I just don't want to party after the prevailing tradition. I want to party my way:
Light exercise on Dec 31. But only water. No eating.
(I have a history of overeating. I really kicked that out of my life in 2005.)
I'll probably eat just a lump of cheese at midnight, to break the fast, then, go to bed.
And not work out on New Year's Day, going back to normal eating then. Then, back to workouts Jan 2.

Kind of a cool idea. Good luck with that.

Here's a cool article I just found on the effects of semi starvation. Dont know if it's ever been posted before. It has more to do with the psychological aspects but here's a line that caught my attention:
At the end of semistarvation, the men's BMRs had dropped by about 40% from normal levels. This drop, as well as other physical changes, reflects the body's extraordinary ability to adapt to low caloric intake by reducing its need for energy. This was after 6 months time and a restriction of about half of their previous, normal calorie consumption.

And unfortunately this one too:
During semistarvation, two subjects developed disturbances of "psychotic" proportions. During the refeeding period, emotional disturbance did not vanish immediately but persisted for several weeks, with some men actually becoming more depressed, irritable, argumentative, and negativistic than they had been during semistarvation. After two weeks of refeeding, one man reported his extreme reaction in his diary:

I have been more depressed than ever in my life. . .I thought that there was only one thing that would pull me out of the doldrums, that is release from C.P.S. the experiment? I decided to get rid of some fingers. Ten days ago, I jacked up my car and let the car fall on these fingers. . .It was premeditated. (pp. 894-895)

Several days latter, this man actually did chop off three fingers of one hand in response to the stress.

I know there are other studies out there done more recently that could give a more scientific analysis (this one was done in the 50's) but it's still an interesting experiment.

Thats scary