Losing weight is difficult. Keeping lost pounds off is hard, too.

There are plenty of people who want to get thinner. Problem is, many of them don't know the best ways to go about it.

You've probably heard the old adage that losing weight is a lifestyle change. That's largely true, but shedding some pounds doesn't have to be complicated. Here are a few things everyone should know before trying to slim down.

  • Nastia11, ThinkStock

    Your Goals Should Be Realistic

    A lot of people start a new weight-loss plan with immediate gratification in mind. But that's not how it works.

    Patience is just as vital of a component to losing weight as what you put into your body. You need to understand beforehand that the changes you seek won't happen overnight; they will be gradual.

    So instead of thinking about losing 30 pounds, for example, set several staggered goals, like losing one pound the first week, then being down 2.5 pounds by the end of the second week, and so on and so forth.

  • Creatas Images, ThinkStock

    A Lot Of It Is Mental

    Losing weight isn't all about physiology--much of it is psychological.

    You've got to remain positive. In fact, you should set aside time regularly to remind yourself of the positive changes you're making. It might sound silly, but take a minute or two each day to just say out loud and affirm to yourself that you're capable of achieving the changes you want and that you're heading down that path.

    Because you are.

  • Hans Van IJzendoorn

    Water Is Your Best Friend

    Drink water. A lot of it. Then drink some more.

    Having a belly full of water makes you feel full, which means that you won't be hungry. So instead of giving in to a hunger pang by eating something that isn't particularly good for you, have a tall glass of water. It has no calories in it, and it fulfills the same purpose as that cupcake without any of the guilt!

  • inxti, ThinkStock

    Take Your Time Eating

    It's easy to get carried away during a good meal. Especially if you've been craving it for a while, as can be the case when you're on a diet.

    But do your best to exercise discipline and eat slowly. By taking your time, your body will feel full. And that's good because when you're done eating you'll be satisfied and won't feel the impulse to eat something in addition to your meal.

  • Stockbyte, ThinkStock

    Don't Overeat

    Portion sizes are out of whack. Just look at this graphic to demonstrate the changes we've seen over the years.

    Be disciplined and limit yourself to what you need, not what your eyes think your stomach wants. Here's a helpful chart to determine how much you really ought to be eating.

    By cutting out overeating you're cutting out a lot of unnecessary calories, and those add up fast!