I've been on a roller coaster with my weight for the last 25 years but now that I've been diagnosed with diabetes 2 I've changed all that. Basically my body doesn't process carbohydrates effectively. To get my levels under control  I had to cut out sugar. Amazing what you'll do when the prospect of injecting yourself every day is staring you in the face. That meant only 1 piece of fruit a day. Like a small cup of frozen blueberries or a punnett of strawberries. Now I  eat a protein rich diet. Like eggs for breakfast. Sometimes bacon. Lunch is salad with sliced turkey meat mixed in. I snack on begga cheese slices. Dinner is different all the time but basically some meat and locarb veges. I still have a coffee with Splenda every day and  I've lost 7 kgs in 2 months. I also use my exercise bike most days for 20-30 mins.  The good thing about having protein is it fills you up and your not hungry an hour after breakfast as I would be if eating cereal or toast.  The reason that it works is your body wants carbs and if your not eating them then it will go to its reserve tank and use that first. If you go on youtube there is a documentary called MY BIG FAT DIET.... Which explains it a little better.  Hope that helps.