Water. We absolutely must drink water to survive, and it has zero calories, so there's no excuse to not drink it. As we typically get much of our water content through foods, when we reduce food intake we begin to dehydrate ourselves, which is dangerous. Also, cold water chills the body and may raise metabolism to get warm again.

Vitamins and minerals. We must have these, too, to survive and so again there is no excuse to not take at least a basic daily multivitamin (which may help reduce some cravings as well). Vitamins are vital in keeping our bodies functioning and our skin / hair / teeth nice. Particularly be aware of electrolytes (potassium, magnesium, salt, along with water balance) and calcium.

Protein. Protein is necessary, particularly if you're exercising. It maintains and repairs our muscles, including heart muscle, which is (last I heard) kind of a requisite for continued survival.

Watch fat intake. Fat has, per gram, more calories than any other source of energy and is stored more easily. Switch to low fat everything, then progress to nonfat. Nonfat food tends to taste like crap (in my opinion) and you may end up eating less because of that.

Caffeine. While caffeine can be an appetite suppressant and can increase your metabolism, it will also act as a diuretic. Drink a glass of water for each cup of tea, coffee, or diet soda you have. Again, dehydration is a potentially serious problem.

Always read labels to avoid nasty surprises. This happens to me all the time and makes for some panicky stress-moments. Also, look up food charts and be aware of the caloric / nutritional content of everything you eat.

Understand yourself. Learn what you need, and when, and why. Everyone is unique and there are no hard-and-fast universally applicable laws. Our bodies are very good at telling us what we need, and knowing what you need gives control over how you choose to satisfy those needs.

Find your binge triggers, be they food or places or people or feelings. Avoid them at all costs. Figure out more acceptable ways of dealing with those triggers than stuffing yourself silly.

Learn when you tend to eat and why you eat then in particular. Plan to be doing something unrelated to food at those times. Many of us find night to be the hardest time to avoid food.

Get plenty of sleep. Steal naps whenever you can and rest when you need to rest. Sleep deprivation increases appetite and makes you age faster.

Self-Control

Keep a food diary. Write down everything you eat and anything else you feel might be helpful to know. This will allow you to measure progress and track patterns over time.

Set yourself rules regarding food. Pick ones that you know you can follow and stick with them. Then, keeping these, gradually add on more rules until your eating is entirely under control. It's hard to restrict yourself all the way at once, and more effective to do it in increments. The idea here is to sort of sneak up on yourself in tiny little stages, adapting to each new rule before making another.

Reward yourself, don't punish. Punishment is not effective and will do more emotional harm than physical good. Calculate how much money you're saving by not eating and add this up until you have enough to buy something you like (but not food). Or, put a penny (dollar, marble) in a jar for every small goal you keep and treat yourself with something (not food) once you reach a certain amount. Remember that these rewards will last longer and give more pleasure than food you would just eat, process, and discard.

Eat slowly, in small bites. Cut your food up into small pieces. Pause while eating to drink water or whatever other liquid you enjoy. It takes a while for "full" signals to get from our stomach to our brain. Also, if you eat over a longer period of time and add more liquids, it can trick your mind into thinking you've eaten more.

Take out only the amount of food you plan on eating. Wrap everything securely up before you start eating and put it away. Don't go back for seconds. Don't nibble while preparing food, either. Those bites and crumbles add up staggeringly fast.

Think about food before and while you eat it. Think about where it came from and exactly what happened to it before it reached you. This works particularly well with meat, dairy, and egg products.

Food associations. Find something that makes you feel vaguely ill or unpleasant, get a picture of it, and put the picture beside your food. Switch pictures frequently and make sure to look at the pictures while you eat. After a while you may began to associate food itself with unpleasantness, which will make you less inclined to eat.

Give yourself permission before eating. Stop and think about it, consider if you really want to eat whatever-it-is. If your answer is yes, then say (or think) something like "I'm allowed to eat this" or "I have permission to eat this".

Plan your meals in advance, for the day or week or whatever. Decide what you are allowed to eat each day. If you know that you will be eating, it may help you avoid eating other things.

If you feel yourself starting to lose control while you're eating, stop. Set your food down, take a long drink of water or some other cool liquid, and take a deep breath before resuming eating. This can help interrupt a slide into binge-mode. Remember to remind yourself that you are still going to finish your food and that you aren't stopping, just pausing for a moment.

Sabotage your food. Make it with too much water, too little sugar, an ingredient you don't care for. Add too much salt or pepper before you eat. You will eat less of it if it tastes bad.

Pick apart your food cravings. If you eat food in separate parts instead of all mixed into one, it feels like you've eaten more and you don't get extra stuff you don't really need. For example, if you're really craving pizza, think about what it contains. Bread, tomato sauce, cheese. Drink a can of V8 or eat a tomato. If you still want pizza, have a rice cake or a few crackers or some other starch. If you still want pizza, have a piece of cheese. Or if you're craving peanut butter, have a handful of peanuts and avoid the added sugar and oil contained in most commercial peanut butter. If that doesn't work, eat a spoonful of honey for the sweetness overload. Same net effect, fewer total calories, no wasted empty added crap.

Distractions

Brush your teeth. Get a travel-sized toothbrush and toothpaste set and use it often. A clean minty mouth can make the thought of eating less attractive. Also, if you brush after every meal and every supposed meal, it's less obvious whether you've eaten or not.

Take a shower. Hot steamy water can suppress the appetite, in me at least, and paying close attention to your body will serve to remind you exactly why you're losing weight in the first place. If you feel clean you may not want to "dirty" yourself with food.

Fidget, take up a new hobby, find something to focus on. Find something with which to distract your hands and / or mouth. Chewing gum works for many people, but check for calories. Sewing or stringing beads is good, detail-oriented and monotonous. Keep yourself occupied.

Exercise. Find something you love to do and do it. If, like me, you're too self-conscious to exercise where people can see, then do it when you're alone at home or in a locked room or other safe place. Make it interesting. The best I've found? Dancing. Find music you love, cover the windows up, and don't even think about what you may look like since there's nobody to see. It's a lot of fun, and it helps you get more familiar with your body as well.

Find triggering pictures. You have internet access, I know you do. When you feel like eating, pick an actress or model that you think is particularly beautiful and search for pictures of them... or for pictures of people you find particularly ugly and fat. It's a slow, involving process and for me at least a great way to avoid eating.

Take a nap. A lot of people think they're hungry when really they're just tired. Also, drink water, since thirst can make you think you're hungry as well.

Purging

This is not good and I am not suggesting it for anyone. In fact, I suggest that you do everything you can to lose any purging habits you may have picked up. It's dangerous and very damaging. But I understand that some people need to purge (hell, sometimes I do) and I think that if you're going to do it then you may as well be as safe as possible.

No syrup of ipecac. I'm not kidding about this one. This shit is terribly dangerous and for use in medical emergencies only. It causes severe and permanent heart-damage. People have died from taking this, sometimes the very first time they've used it. I've tried it, it sucks, don't do it. Trust me here. Remember that if you die in painful screaming misery, you'll never reach your weight-loss goals and will probably be found crumpled up in your own assorted by-products.

No diuretics or water pills. There's no point. They don't make you lose any real weight, only water, and water loss does not count as weight loss. Dehydration can kill; you want more water, not less. A water-starved body will be more hungry as well and will hold onto everything you do put into it. If you're retaining water, drink more water and a little caffeine. It will go away eventually on its own.

No laxatives. They're habit-forming in that after a period of time your digestive system will not function without them. Overdoses of laxatives can dehydrate you to the point of death, or rupture your intestines. If your digestive system isn't behaving right, go for fiber supplements like Metamucil instead, they're good for you instead of bad.

Avoid throwing up whenever possible. Stomach acid is vicious. It eats away teeth and makes them ugly. It eats away at your esophagus and sphincter valves. Over a period of time, throwing up will disable your upper digestive system as thoroughly as laxatives will disable your lower digestive system. It also puts terrible strain on heart and head, and can cause dangerous electrolyte imbalances.

Avoid punishing a binge with an immediate fast. If your body expects large amounts of food, then depriving it cold turkey may cause even more hunger and binging. It's a cycle... binge, fast, binge, fast. Don't start. Regulate your food instead and be gradual with changes in how much you eat.

Remember that exercise in itself doesn't really burn off all that many calories and is pretty useless for burning the results of a binge. However, exercise raises metabolism and builds muscle, and the added muscle raises your metabolism even more, so you burn more calories all the time. Design yourself a steady exercise program and follow it consistently instead of sporadically overworking and hurting yourself.

Keep a box of baking soda, a cup, some water. Rinse your mouth with baking soda dissolved in water after purging. This helps neutralize acids and spares your teeth and mouth somewhat.

If you use laxatives, make very sure to be well-hydrated beforehand. Drink extra water and take potassium. It really helps against cramping, pain, and dizziness.

Drink a ton of water while binging. Say, a full glass of water between every couple units of food you're eating. Not only does this fill you up faster with fewer total calories, while still letting you get the taste of the food you want, it makes purging a hell of a lot easier and more effective. Be sure to drink water before a binge, or right at the start of one, and then space the water throughout so it mixes with all the food instead of just sitting on top of it.

Eat the healthy stuff first. Fruit or veggies or a salad or something fairly low-cal that you wouldn't mind digesting as much. Since it's hard to get everything up, and since food comes up roughly in reverse order to how it went down, cushion the bad high-cal junk with safer foods.

Secrecy

Depending on your situation you may have a greater or lesser need to keep people from finding out your behaviors.

Don't raise suspicions. Once people realize what you're doing, you'll be watched and monitored and suspected. Start hiding your habits and practices before anyone even sees them. It's much easier to keep people clueless than it is to fool people who know something's going on.

Check the fridge when nobody else is around. Find foods that you would have eaten and get rid of them, for example, three eggs and a piece of butter. Then if someone asks, you can say you had scrambled eggs and are really full. And if they check, the ingredients are gone, which reinforces your story. Consider dishes and silverware as well.

Don't bring up the subject of food around other people. Have your excuses for not eating ready in case they should bring the subject up. Some excuses I use : "My stomach's a little upset", "I'm too (tired, excited, nervous, busy, etc) to eat", "I don't feel like (whatever food it is), I'll get something later", "I did eat, didn't you see?", and "I stopped by (Arby's, Burger King, Subway, etc) earlier".

If you plan to say you stopped by a fast-food place or restaurant, be sure to take out several dollars from your wallet (or wherever you keep it) and hide them someplace they won't be discovered. Be sure also to stop and wait for about the amount of time it would have taken to eat the food before going home, and know what you supposedly ordered. The money you hide can be saved up as a reward.

Spend different meals with different groups of people, tell them all that you had a big meal earlier or will be eating something later on. Make sure the different people will not be comparing notes. Or plan your schedule so you're too busy at mealtimes to eat then.

Trash. Watch where you dispose of uneaten food or other "evidence", make sure that it isn't going to be seen or found by anyone. Wrap food up and throw it away outside the house. If you live alone, always take the trash out before anyone else comes over.

Buy food. People are fairly predictable. If they see you buy food and come home with food, then they just naturally assume that you eat it as well. Get things like crackers and cookies and dried fruits, keep them in your room, and carefully pack them out again later to throw away. Careful, this can be a little dangerous if you're prone to binging and have trouble keeping food around, or if you feel guilty about throwing food away. If the food's something you don't like and won't binge on this may be easier to do.

Don't get angry. Don't deny everything if confronted. People will believe a little truth with a big lie much easier than a huge lie. Act as if it's no big deal instead of reacting emotionally and people will tend to believe you.

Tell people you're on a diet, you became a vegetarian, your doctor has you eating only certain things, whatever. Often people will be very helpful in keeping you from eating if they think there's a socially acceptable reason for it.

Don't show off your weight loss until you've reached the weight you want to remain at. People will start to watch you more carefully and maybe ask questions, and you want to avoid calling attention to yourself.

Re-feeding

Eventually you may decide to try a more regular-type food intake. This sounds much simpler than it actually is, particularly if you've severely restricted or been purging.

Tums are your friends, don't leave home without them. There will be much stomach acid. It will hurt like holy fuck. Watch your acidic-foods intake, like fruits and veggies, because they can be particularly hard on insides before your chemical balance re-establishes itself.

Yogurt. Stick with the nonfat kind if you like, but eat as much as you can take, helps re-establish healthy intestinal flora.

And gingersnaps. Great for settling the stomach.

Just because you're eating doesn't mean you have to eat like a fat ass. Diet and nonfat foods are perfectly acceptable. Hell, everyone else eats them... and it doesn't seem to register with watchers that there's a difference between a 600-calorie plate of turkey and a 150-calorie package of fat-free turkey slices, or a 200-calorie bottle of Sobe and a 15-calorie bottle of Sobe Lean. Exploit as desired.

Bread products are great. Fiber is vital for rebuilding and strengthening atrophied intestinal muscles. Be warned, though... there may be gas, irregularity, and general discomfort for a while as this happens. Always know where a nice private restroom is.

Soy milk. The nonfat kind if you like. You will need extra protein if you have much muscle to replace, and it's pretty low-cal.

Avoid saturated fats and cholesterol.

Continue to take your vitamins, damnit.

Listen to your cravings, your body will have a very good idea of what it needs to take in for proper reconstruction. Continue to take whatever precautions against binges you need.

Re-hydrate. Very important as your body gets used to processing food. Drink V8 and soymilk and non-acidic fruit juices like mad.

Miscellaneous

About weighing yourself. Everyone has different methods here that work for them. Many people get discouraged with weighing themselves every day, because our weight is not a stable thing and can vary drastically from little insignificant things. Try to get a better overall picture through the fit of your clothing instead.

Throw food away before you eat it. A lot of people feel guilty and don't like to toss food. There's nothing wrong with this. Remember, though, that food gets discarded any way you look at it... purging, digesting, tossing... and isn't it better to get rid of the food before it puts fat on you instead of after? If you still hate to discard food, see how much of it you can donate to your local shelters and community service programs.

Apple cider vinegar (or possibly vinegar in general). It may help raise metabolism and burn fat. It may for you work as an appetite suppressant. Be careful, though, it may also hurt your stomach or cause nausea. Don't take more than a couple teaspoonfuls at a time. Try it mixed with honey in a glass of water, or in diet 7up or other clear carbonated soda about twenty minutes before eating, you may feel full quicker or decide not to eat at all.

Eat dense foods. They'll feel like more in your stomach. Light or fluffy foods tend to compact, and don't fill you up as well. Drink lots of liquids.

Avoid refined foods. They're in large part empty calories, and they don't satisfy the body or supply good solid nutritional requirements. The closer to natural you eat, the more value you get per bite, and the less you'll need to eat. Substitute whole grains for white flour and raw sugar for refined white sugar particularly.

Don't fill up on bread. It's deceptive. Six slices of bread can feel the same as one sandwich in your stomach, and it gets processed very quickly. If you do eat bread eat whole-wheat or grain bread, which will feel denser in your stomach as well as be healthier for your digestive system. Make a sandwich with vegetables or low-fat cottage cheese or salsa instead of eating bread plain.

Avoid alcohol and other drugs. Anything that can affect you will affect you more strongly and in different ways, and anything that affects your mind will lower your level of control. I hear the munchies are a nightmare when you're trying to lose weight, and waking up with a hangover surrounded by half-eaten food evidence can't be too much better.

Be careful with over-the-counter weight loss products, including the natural and herbal ones. They speed up your metabolism, yes, but they're designed to be taken with a decent amount of food and can be very very bad for your heart, head, digestive system, and nervous system if you use them with a severely restricted food intake. They can also mess up your sleep cycles, and people with irregular sleep cycles tend to eat more. I would suggest half doses to start with since they'll have more of an effect on someone eating very little, and watch for signs of panic, anxiety, or irritability.

Don't get discouraged with yourself. You didn't put on weight overnight, and it won't come off overnight either. These things take time, and time will pass no matter how much you're eating.