Please do not fall for the line of the shysters hawking diets they say will cause you to lose 30 pounds in 30 days. That is not going to happen.
Here is the way that body weight is determined: calories in contrary calories out determines body weight. If you eat MORE calories than you burn, you gain weight. If you eat fewer calories than you burn, you lose weight. That's IT …. there is nothing magic about it. The old saying, "you are what you eat" is actually pretty accurate …. at least your body weight is determined partly by what you eat. The other component is how many calories you expend.
When I hear people talk about "diets that really work", I always want to stop right there and give the above lecture. The ONLY diet that will cause you to lose weight is one in which you eat fewer calories than you burn. It does not matter how you count those calories, either. You can count calories, carbs, fat grams or use a "points" system …. the objective is still the same; fewer calories in and more calories out is the cause of weight loss.
A pound of body weight is worth about 3600 calories. If you eat 3600 more calories than you burn, you will gain a pound of body weight. On the other hand, if you eat 3600 more calories than you burn, you will lose a pound of body weight.
When I speak of spending calories, I'm talking about the calories your body burns that just keep you breathing and your organs functioning (the brain requires about 400 calories each day) AND deliberate, intentional, on purpose physical exercise like walking, running, jumping rope, swimming, bike riding, etc.
There are TWO components to any diet that actually works:
1. Consuming fewer calories 2. Burning more calories.