Hi, I would suggest cutting out food that have added sugars first such as sugar sweetened beverages, fruit juices, confectionaries. Quench thirst with water, non-sweetened tea/coffee. Replace unhealthy snacks with a handful of baked nuts, greek yogurt, a small fruit or cheese with crackers. 

There are many different diets which can help with weight loss and they can all be used as long as you are aware of the issues with each of them and you have a health care professional guiding you along. Some diets may not be suited to certain health conditions. They can all lead to weight loss but the difficulty is in consistently keeping to these diets. 

For weight loss in diabetes patients, it will be important to get your doctor's advice. There are certain diabetes medications which can help control your diabetes and promote weight loss. And if you do want to embark on certain diets, your doctor will need to advice you if the diet is suitable based on whether you have other health conditions like kidney problems and risks of low sugar.