the best way to diet is you schedulle with 5 times eat a day. It's not joking, but it's true. your body need metabolism and you must eat to avoid hunger, why? after you get hunger you will eat more food and it will become more fat. Each time you eat, should contain 5 things: healthy fats, quick digested carbohydrates, protein, fiber and drink without sugar. It all helps your body metabolism, blood sugar does not drop and there is no accumulation of fat.
Start breakfast with a bowl of cereal like fiber and nonfat milk and bread wheat and do not drink juice but replace it with tea. Morning snack eat a bowl of cheese and blueberries. If you do not like cheese, try apples with peanut butter or a mixture of nonfat yogurt. Fill lunch with grilled chicken breast so that your protein needs are met. You can eat with lettuce, corn, black beans, and shredded cheese and other vegetables, may add tortilla chips and salsa. For afternoon snacks, any fruit mix likes apples, strawberries and Jamaican grape fruit. Then last supper with baked corn tortillas, ricotta cheese, dried tomatoes and grated cheese.
you eat like that everyday but in a week you cheat a day, because routine eat can make your body get fat. for more information read http://www.fees-1st.com

I am assuming that you are referring to the pre-packaged meal programs that are available online. In todays fast paced society, many people eat out at fast food restaurants, and despite going to the gym, people are not losing weight. The prepackaged meals are often a little more costly than eating out, however I have seen friends who have lost quite a bit of weight.

Nutrisystem - is the only one that I know that people have used and lost weight.
ediets.com
weightwatchers - my mother used them years ago, and sad to say, I don't believe she lost any weight.
Jenny Craig
Medifast