Rani Mukherjee said that Jowari Roti in her diet plan helped her reduce 7 kgs. Is Jowari Roti that good? How?

It is said that Jowari roti is the best food when it comes to reducing the wieght. But seems no one has published any research paper on the subject.How can Jowari roti help an obese person is my concern area. Is it a good food for diabetic patient too, as it is showing in search results?