Some days I eat 2,000 calories and some barely a 1,000. I'm short -- 5'2.5" tall and can't see that I would need 2,000 calories day in and day out irrespective of exercise. More activity would seem to indicate the need for more calories -- but then I read an interview with Korean ice-skating champ Kim Yu Na's coach who said Na eats a strict 1,200 calories when training and yet she must be burning 10x that. She is 5'4" tall. So unless the coach is lying -- it seems that we might be grossly overestimating our caloric "needs." Thoughts?
To paraphrase Art DeVany, the energetic landscape of the hunter gatherer is a fractal with periods of overfeeding/plenty following periods of underfeeding/starvation.
At least in the field of longevity research, there seem to be tangible benefits from calorie restriction (although this may be stimulated by simple protein/methionine restriction) such as telomere preservation and stimulation of other regenerative pathways (the idea being that the body switches from "reproduction" to "preservation").
Intermittent fasts, whether planned or by happenstance seem to work fine for many people. Chronic calorie deprivation could very well be damaging overtime as cortisol and other stress hormones are elevated and available resources are depleted, especially concurrent with a high training volume.
I don't think that a lot of hard-core professional athletes are particularly "healthy" so I don't put much credence into their diet/exercise habits. Look at Michael Phelps' diet!
Here is a picture of what he eats in one day BTW...
I'd say fluctuation good. I mean depends on your definition of "need" is. I "need" more than 1200 calories in a day to not rip someones head off. Sure I could live on less, but a couple of other people may have to die for it. But hey I'll do it for a day or two....then eat 3000. I like to mix it up too, and actually I think most paleo thinking would agree with that approach.
I find that my intake varies a lot day-to-day. Sometimes I'll have a busy day and not eat as much. Then, over the course of the next couple of days I end up having a stronger appetite and making up whatever I didn't eat on my busy day. When I look at weekly averages though my average calorie intake stays pretty steady. I think our body regulates our intake, but it seems to balance it out over longer periods instead of making us want to eat the same amount every day. This probably worked better for Grok who couldn't always get the same amount of food per day.
I think it's good to vary your intake.
I doubt our ancestors consistently ate X-amount of calories a day. I imagine it was probably a bit of feast-and-famine for them, depending on the success of the hunt.
As far as the 1200 calorie thing goes, no, I don't think that's a healthy amount for an athlete. She's severely under-eating for the amount of training she does. I maintain on easily 2,000 calories on a lazy day, more when I'm active (and by active, I mean: cleaning the house, hauling my butt across campus, mowing the lawn).
Then again, our caloric needs are individual, and as Annie stated, the quality of the food probably plays a larger role in our weight/health than most realize. For me, though, I need ample amounts of food with plenty of fat to stay sated. I would probably get very gaunt very quickly on only 1200 calories per day. :)
I forget what the diet is called but there is one where a person would eat 500 calories one day and binge the next day and just keep alternating to lose weight. The theory behind this way of eating is that you would get the benefits of fasting but without the metabolic slow down. Many people were successful at losing weight eating this way. Not sure if it had to be done long term but I'm sure if you did some research on it you would find the book or more resources.
This just proves to me that all calories are not "equal." She is working her tail off and only eating 1200 calories a day. If she were on a high-fat, rather than a low-fat diet, (just an educated guess) she would be getting a lot more calories and she would be a lot less hungry, while still maintaining her physique and athleticism.
We have the hardware to deal with a feast/famine situation, but is it optimal? I'm not sure, from my reading a little fasting, and in particular protein fasting could be beneficial.
There is no way an elite athlete could sustain themselves of 1200 calories a day through a season of competition. It is possible that during preseason base training that she is on a restricted calorie diet to lean out from a rest period over the off season. Otherwise the coach is simply foxing.
I'd say if you listen to your body you'll figure it out, each person is different and some days you need more than others. It seems you are already figuring that out by flucuating your intake.
I'd be concerned over 'binging' techniques or severe restriction in your intake. Find a happy medium that works for you and tweak it!!
So How many calories--sorry long post? 10 Answers
Help Me Get 4k Calories! 7 Answers
calories needed to lose weight? 6 Answers