For the Most part for me, the Nutrition is what is Important. Having lived through being a type 2 diabetic, and then losing 100 pounds, I discovered over years of self preservation that empty calories, empty carbs are the worst.
Cokes, potato chips, cookies, and other such items are examples of empty carbs. The calories that these foods and drinks provide do not have the nutritional punch that foods dense in carbs, such as Oatmeal, carrots, broccoli, and other vegetables, cooked or raw, are the way to go. The nutrition is dense and there is also Fiber which helps all this come out the other end properly.
I may have been on a low fat diet, for the most part, but my body would take empty carbs and turn the excess sugars into fat.
Exercise also is crucial for allowing the foods you eat to be absorbed properly and get the most bang for your buck.
Drinking lots of water helps also.
Hope this answer helps.