Your body uses glucose as the main source of energy. When you eat high energy foods, your body starts producing insulin which is a hormone that helps control glucose intake. As the body's insulin levels rise, your body shuts down fat burn and starts worrying about all the glucose coming into your body meaning your fat burn stops and your fat gain starts. So in a nutshell, as you eat more energy than what you need, that glucose coming in is converted into fat storage. So how do we keep the body from raising its insulin levels so it can keep burning that fat you so dearly want to get rid off? The answer is simply eating foods that do not cause an insulin spike. Any food that is high is sugar and carbohydrates are going to spike your insulin so the best diet is a diet that is high in protein(good for those healthy muscles), high in fat(healthy fats are vital for your organs) and you should keep the carbohydrates coming from plants since you still need some. Eat REAL food!
Studies have been done where western diet was introduced to areas in the world that have enjoyed a diet of REAL food and the results we straight scary. People were getting sick left and right. It's no surprise that type 2 diabetes is a product of the western diet.
To be able to stop weight gain, you have to stop putting high refined energy into your body and start enjoying the real foods we have all around us. As the insulin stays down, your body shape changes and your fat content will slowly start walking away! REAL talk, REAL food!