I am about to get back to serious weight lifting, and to do that requires some good nutrition to be effective. I needed a refresher on what I knew so I dug up an old thing I wrote about nutrition for some extra motivation and decied to post it and read it.  Sorry for the long read, but it is informative. 

The biggest thing that people need is a proper amount of calories a day. The way to figure this out is to use their calculator based on your BodyFat % and your current wieght and age and activity level. This will give you the amount of calories per day that you need to eat to maintain current wait with your lifestyle. I'll run through tings based on a 2500 calorie a day diet.

Ok, this does not mean that you can eat what ever you want all the way up to 2500 calories. While technically this can work you will have a lot of side effects for yourself that can really screw your body up. So no 2500 calories a day of cake and ice cream. Now what do you need 2500 calores a day of well 3 things. Protien, Fats and Carbs.

Now you may be saying oh no fats are bad for you no no no you lie. Well that is completely wrong. There are 2 basic types of fats Saturated Fats and Unsaturated fats. Your saturated fats are what is solid at room tempurature. Your unsaturated fats are liqued at room tempurature. Well your body NEEDS unsaturated fats. Now this is easy to obtain through fishes and gel caps. Just when you get that steak trim off that saturated fat cuz it is bad.

Also you need protien this is the good stuff this is what heals your body. Basically, when you are sore from a workout or you cut yourself your body goes to the protien for the amino acids to promote healing because when you work out what you have done is created tons of micro tears in your muscle and the protien stimulates muscle growth.

You also need Carbs. Carbs are great they can burn body fat at a higher rate than than anything else if used effectivly with some caffiene. :D Carbs are what your body burns through and when you get the right amount your body will hurry and burn through that really really fast it speeds up the metabolism. That is why you can easily get hungry after eating just rice.

Now, lets put all this together as one to see how it works. When you eat effective portions of all 3, which I will explain next. You can literally turn your body into a fat burning machine and be able to burn nothing but body fat, but it takes precision and patience. Basically you need about 6ish meals a day that vary in size. The reason you eat so many is once you eat your body's metabolism is no high speed and peaks after about 2 1/2 hours then if you eat around then it keeps it at that high rate of speed. So by eating about every 2 1/2 hours to 3 hours you will maximize the amount of food burning time.

Now for the first month you will not lose any weight in fact you may gain a pound or two no worries. What is happening is your body is slowly speeding up the metaoblism and getting used to the food consumption. After about a month your body is now used to the food and you will drop your calories from maitenance level of 2500 to 2000 calories. This will allow you to lose nothing but fat with out any extra effort physically a week.

Now I will go a bit into the math of loseing weight because in a sense all weight maitenance, losing, or gaining is basic math.

A few things to know is that in order to burn a pound of fat you need to burn 3500 claories a week, or 500 calories a day. That is for 1 pound of body fat. That should be done with nutrition I do not suggest ever going below 500 calores below maitenance level a day. The rest should be burned with cardio workout, running what ever. Not weight lifting though that is something completely seperate don't even count that.

Now how do you figure out how many protien fats and carbs you need a day well that is easy. You know that you need lets say 2000 calories a day so we just do some simple conversions.

1 gram of protien = 4 calories
1 gram of carbs = 4 calories
1 gram of fats = 9 calories

the suggested scheme to follow is 40 40 20. 40% protien 40% carbs 20% fats.

Now 40% of 2000 is 800. So you need 800 calories or 800/4 = 200 grams of protien and 200 grams of carbs.
20% of 200 is 400. So you need 200 calories or 200/9 = 22.2 grams of UNSATURATED fats a day. Now that may seem like a lot and when you eat clean foods it is a lot of food, but look at it this way eat clean food to equal these stats and you will be eating a lot. Now what do I mean by clean food. Well stuff like grilled chicken breast eggs broccolli fruits vegetabals tuna things like that fish. There is a food database at bodybuilding.com that gives the proportion sizes and stuff like that to create a perfectly balanced diet.

Also when I refer to carbs I don't mean sugar, potato's, fires anything starch that almost imediatly turns to fat well really fast anyway. What I am refering to is stuff like grits, oatmeal, or brown rice (no white rice) You can also have wheat bread but not too much and be sure to get bread that does not have fructose in it.

The fats you need mostly come from fish the quickest way to get it is to have fish oil gel caps or flax seed oil.

Also, the reason I say that weight lifting is completely seperate is because you are trying to gain muscle and while you won't gain a lot you will be burning that fat and converting some to muscle the more muscle you have the more fat you will burn faster. So depending on how you want to do it you could bulk up really big and then do a clean cut to a low body fat range.

Here are some things to be aware of. You have to change how you look at weight loss it can't be oh I need to lose x number of pounds it needs to be I need to lose x number of bodyfat %.

Now some things to keep in mind women and men are made up different so they have to have a certain amount of body fat that is higher than men, but you wouldn't be able to tell.

For guys: body fat percentages
3% = dead
3.5 - 4% = Bodybuilding competition weight
8% = 8 visible abs
9.5 - 10% = 6 visible abs
13% = average male athalete
16% = average male
32% and up = obese

for Women: Not as sure since i don't give much advice to women.
7% = dead
9% - 10% = Competition
14% - 17% = visible abs
20% - 24% = average girl
38% and higher = obese

Thes are all relative but pretty dead accurate.

I hope this helps someone now don't take my word solely for it go read http://bodybuilding.com they also have forums with nutiritionists that can give you pointers and all that.

btw, losing fat is 80% nutrition 15% phyiscal and 5% mental, though that 5% can really cut into it big time when starting.