Looks like I've been doing this wrong

Until now, my diet basically involved eating about 500 calories a day for a week then moving up to 1000 for a week followed by a fortnight of 1500 calories (where my weight would plateu) in the hope of keeping starvation mode at bay until I repeated the cycle.

Reading the forums here I get the impression my fortnight of low calories will be doing serious harm to my body. My goal for today was going to be 500 calories (which I met by late evening) but I'm now going to consume another 450 and from tomorrow will aim to stay between 1200 and 1500 per day on a permanent basis.

One question though for those better informed than I - I've never been able to eat breakfast without feeling ill in the mornings and often found that I'd not get the time to eat at work (but get plenty of fluids). This means the majority of the time I get all my calories between the hours of 1900 and 2300 and go hungry the rest of the time. Can anybody explain in simple terms whether (and how) this may be doing damage to my diet or am I ok to keep this lifestyle up as long as I get the correct calorie intake and eat healthy food?

Depending on what you consume between 1900 to 2300 hours eating this way may give you energy ups and downs when you don't need them i.e. just before going to bed unless you are up all night there is not much point eating all your food at night.

Also your body will absorb nutrients better if you provide them in smaller meals and spread out over the entire day. You also make your body run on empty by only eating a few calories all day.

However the fact that you are keeping your body hydrated helps a lot, if you say you have time to consume fluids, how about drinking some home made soup?

I am not a doctor or anything these are just my perceptions.

why not substitute a protein shake for some of your fluids?

Well this is my two cents worth.  I was always a lean, muscular girl never had a weight issue.  Had three kids, and gained (kept) twenty lbs from my last two pregnanices. I wasn't concerned, I lost all the weight from my first pregnancy, and like I said I was always lean and thought 'I'll bounce back no biggie'.  I was about a size 11/12 at that point. 

here's the thing, due to lifestyle I never ate breakfast, and wouldn't eat until maybe 2p.m., again at dinner, etc.  Basically, my eating habits were irregular and more importantly I did nothing to retain any muscle.  I didn't overeat, at times for sure, but on the whole no.  Over the next few years I lost a few lbs here and there, usually put it back on in a few months, but didn't care really.  I was still like - don't worry you'll lose it.  Needless to say I didn't lose it, but I didn't gain - in weight anyway.  I did lose my muscle tone and grow another 1 1/2 sizes! 

Why is that?  When you wake up your body is in fasting mode.  It will continue to fast until you feed it.  The only way to keep your metabolism burning hot, is to feed the furnace.  so, in my case my body stored much of what I got, although, I ate much more than you so I can't say I was in starvation mode, but my metabolism was running slow.  I ate late at night all the time.  That's perfect for your body because when you go to sleep it does nothing but store fat.  Your not feeding your body enough protein, so it is going to eat it from your muscles, which gives you less muscle - which over time also slows your metabolism down, and over time you will weigh the same but look fatter because you have only increased fat stores with yo-yo dieting. 

More specifically, eating all your cals in a four hour period also slows your metabolism down, and doesn't give you the needed protein or nutrietnts.  Your body cannot store protein, so it will turn what you don't use in the immediate period following your feeding time into - fat.  Also, it wil have nothing to build muscle with the rest of the day, or the esential amino acids in protein.  I'm happy your going to start eating, but you would do your self a great service by eating small meals over the day.  You will burn MORE cals by spreading out your 1500 than by eating them in one sitting. 

If you don't like breakfast fine.  Eat one-2 hours after awakening and then eat small 200-300 meals the rest of the day.  If you can start doing some strength training - this will boost your metabolism even when resting.  Good Luck!!

I can't eat most things within an hour or two of waking or I feel sick the rest of the day. The exception to this, for me, is fruit! I find that one serving of fruit doesn't give me the ickies all day like other things do.

Also, for eating at work, why not pack a granola bar or a Special K cereal bar or a Nutrigrain bar so you can eat on the go? How about some beef jerky? An apple?

Gotta feed the body to keep it healthy. Developing a habit of large night-time meals probably isn't going to help you in the long run with maintaining your healthy weight once you reach it.

I also like to "break the fast" (breakfast) with a piece of fruit.  I find that an hour or two after my fruit, it is easier to eat breakfast.

I eat the bulk of my daily calories at lunch.  I tend to eat a light dinner, salad or fruit or steamed veggies or something.

Thanks for all the helpful advice.

I'll try the route of eating some fruit for breakfast each day as it's certainly lighter on the stomach than cereals.

Not sure I could find the time in my life to snack on 200-300 cal meals throughout the day but I shall try my best to cram in some fruits and a dinner each day.

A nice big glass of milk also goes far in the morning. That and a big piece of fruit is an acceptable (if not ideal) breakfast.

Do make sure you stuff something down your gullet at lunchtime. Maybe a prepackaged meal bar or something?