It is unscientific to say that drinking carbonated drinks is used to lose weight. The most scientific way is to ensure normal eating habits and sleep, "full in the morning, full at eight o'clock in the afternoon and full at seven o'clock in the evening."
You can also choose eggs+bread+milk or soybean milk (nutritious but not fattening) in the morning, and have a normal diet at lunch. Protein is a supplement to meat. Sugar and starch are the main culprits that make you fat, but that doesn't mean not eating these two things or eating more meat, because a balanced nutrition is normal.
If you lose weight, you can have a better dinner, but not too greasy. Snacks must be stopped.