Depending on who you are and what you do, you are going to need to change your diet. But not all of us are nutritionists, so here's some help.
1. Read the label! This is the best way to learn about a food. It gives you almost all the information about that food you'll every need. If your trying to lose weight, you're going to choose foods with low calories. If you want to gain weight for a football team or something, your going choose food with lots calories. Too many calories, not enough exercise, and eating too much at one time, can make you fat.
2. Fat, is something that can be very deceiving. For example, if your trying to loose weight, your gonna look for food with low fat content, BUT there are some foods that have good fats, these fats are like monounsaturated fat and polyunsaturated fat. These fats add calories from fat, and so does trans fat and saturated fat, so they combine, which can be confusing. It's important to look at the saturated and trans fat content. If you see 20 calories from fat on the label, but 0g of trans fat and saturated fat, that means that there is polyunsaturated fat and/or monounsaturated fat. Polyunsaturated and monounsaturated fat are good for you. They protect your heart and increase 'good' cholesterol. Its good to have enough good fats, but all good things have to come to an end.
3. Sugar, resembles fat in many ways. There, again, is good sugar and bad sugar. We all like sugar, it's natural. And that doesn't mean if your trying to loose weight, you can't have sugar at all. The bad sugar, sucrose, makes you fat, because its high in calories, and it's sweet. The good sugar, glucose, is a natural sugar that comes from fruits and other natural plant sources. Glucose, the good sugar, goes into your blood, not your belly. It 'enriches' your blood, in a way. Sucrose, the bad sugar, doesn't go into your blood like glucose does. To put it simple, its raw energy turned into a sweetener, and when energy isn't used (exercise), its stored (fat). Thats why on the label, sugars is below carbohydrates and indented, indicating that it is related to carbohydrates. So eat fruits, avoid candy and sweets, if your trying to loose weight.
4. Salt, doesn't really affect your weight so much your health. If your an athlete, you have to make sure you have enough salt, or sodium. When you perspire, or sweat, the liquids your body releases, is combined with sodium, so you loose some salt from your body when you sweat. But if you consume to much salt, it could really hurt you. Even out your sodium intake by reading the labels.
5. Potassium, mostly affects your blood. Its very important to athletes. This is because when you sweat, you perspire sodium and water, and the potassium gets too low. When this happens, its like having water as blood, it just doesn't work. Potassium is important to everyone, but mostly to athletes. And it doesn't effect your weight, so people who're trying to lose weight, don't worry about it.
6. Cholesterol, has plagued many many people. The cholesterol on labels of food, is the bad cholesterol. So don't say that you can have food full of cholesterol because its the good kind. The good cholesterol in food is measured in polyunsaturated fat and monounsaturated fat. This stuff is bad for you, limit your intake of the bad kind no matter what your trying to do with your body.
7. Carbohydrates, is energy. Now, some people thing that energy is stored as fat when it's not used. I am one of those people, as I said before. But that does not mean that carbohydrates make you fat. Imagine, if your body didn't have any carbohydrates, what would it be running on? Fat. But if you used those carbohydrates, even in something as simple as being awake, walking, and more active things, like running, exercising, etc., the carbohydrates won't be turned into fat. If you are going to run a marathon, and have a major carbohydrate consumption, you'll burn those carbohydrates up in about 45 minutes, depending on how fast your running. So, if I was trying to loose weight, i wouldn't worry about carbohydrates as much as I would calories.
8. Dietary fiber, is a mineral that is released to clean out your system and get rid of waste. If you look at a label, dietary fiber is below carbohydrates and indented, sugars is also below carbohydrates. This means that dietary fiber and sugars are types of carbohydrates. Like I said before about sugar being raw energy. Dietary fiber is important to any diet. If you don't have enough of it, you won't 'go' enough. Antioxidants with dietary fibers is powerful. Antioxidants can work together with fiber to release worse wastes. Antioxidants lets waste release when you breathe and urinate, too. No matter who you are, you should have a good amount of dietary fiber.
9. Protein, lets your muscles develop and grow easier. It's the last item on a label (besides the vitamin and mineral content). You should have as much protein as you can in your diet, no matter who you are. Protein comes from many foods, meat especially. The problem with protein is that it usually comes with fat, like in meat. A good low fat alternative to meat is tofu. It's pretty much a chewy block of protein. Have as much protein you can get, that's to everyone.
10. Vitamins and minerals, are essential to life. Your body is made up from water and minerals, and the vitamins help with health. If you don't have enough vitamins and minerals, you will die, but that is only in very extreme cases (not eating for a week or a long amount of time). If you have too many vitamins or minerals, your body will just release it in urine and stern. There are certain vitamins or minerals that you can have too much of (vitamin A, iron, only a few others). You should also have a large variety of vitamins and minerals, too, not just vitamin A, C, and D, because it won't do. Again, vitamins and minerals are for everybody, kids, adults, seniors, men, women, jocks, skinny people, everybody.
11. Taste, is a big role in the food you eat. If your not on any particular diet, you probably don't care what you eat. But you should. Taking some potato chips and sitting on your couch and watching TV isn't really an ideal lifestyle. For people not on a diet, don't just gorge yourself with junk food. Snack on fruits or vegetables, or something healthy. It's better for you, and you'll feel better.
Evening out your intake of fats, sugars, sodium, and cholesterol can change your health a lot for the better if you have a good intake of them.
Remember not to be confused with fat content and sugar content.