If you have trouble estimating portion sizes, find yourself eating too often or typically choose foods high in fat and calories, meal replacements may work for you. We all know that losing weight is one thing, but keeping that weight off for one, two or even three years or longer is a completely different story. For people who really have trouble changing their eating habits permanently, using one meal replacement per day may be just the ticket to keep weight from coming back. As an added bonus, reducing body fat typically results in decreased risk of diabetes, high blood pressure, osteoarthritis and heart disease.

But just like other diet plans, meal replacements aren't for everybody. If you need the taste of real food and prefer to chew rather than drink your meals, you're probably better off sticking to healthy foods, not meal replacement shakes and bars. A meal of six baby carrots and a turkey sandwich on whole-wheat bread with mustard and dark green lettuce is just as healthy as a 220-calorie meal replacement shake.

Six Ways to Maximize Your Results with Meal Replacements

Use these helpful tips to make meal replacements a successful part of your weight loss and weight maintenance plan:

1. Use a meal replacement for no more than two meals, or one meal and one snack, per day, unless you're closely supervised by your doctor.

2. Choose meal replacements that contain at least 200 calories. They should also have a balance of carbohydrates, proteins and fats to provide adequate nutrition and decrease between-meal munchies.

3. Use meal replacements at the meals that cause you the most trouble. If breakfast is always a donut on the run, drink a Kashi shake instead. If you routinely skip lunch, or succumb to the fast-food advertisements, grab a Slim-Fast lunch bar. If you can't find the time to make a healthy dinner, have a Snapple-a-Day.

4. Mix and match so you don't get bored. You can use two meal replacements on some days and just one on others when you have more time to make healthy meals. Also, try lots of different meal replacement products to keep your taste buds happy. For example, you could have a Slim-Fast shake for breakfast and a bowl of Special K for lunch.

5. Choose fresh fruit for snacks twice a day for added nutrition and fiber. If you're drinking lots of shakes, you'll be happy to have something you can chew!

6. Maximize your weight loss by making your traditional meal well balanced. To do so, make your plate look like this: Fill half with vegetables (raw or cooked, your choice), one-quarter with protein (chicken, fish, tofu, legumes, red meat) and the remaining quarter with the starch (pasta, potato, rice, bread).