Don’t neglect insulin.
Macro breakdown when in a calorie deficit is very important, at least from a protein sparing standpoint. A steady stream of new amino acids into the body has been shown to be protein sparing, especially when weight training is added. A steady stream is necessary because our bodies changes the excess aminos into fat, glucose, or immediate energy.
There is a vast amount of other nutrients and phytochemicals that are found in fruit that could aid in weight management and if not are shown to promote a healthful life.
The Krispy Kreme diet, would leave you plugged up to no end. Very low fiber intake. It is also deficient in many beneficial fatty acids which can aid in wait loss. Think CLA for starters.
Fruits aren’t that high in glycemic load making them usable even on a blood glucose controlled diet. The more processed a food it the higher it GI and GL become, fruit are good example of a non processed whole food carbohydrate source.
High fiber high water/ low calorie foods are beneficial to weigth management. They take up a large amount of space in the stomach which supports feeling full. The churning of the stomach upon the fiber delays gastric emptying wich lowers the GL of a meal keeping insuling in check.
The “hybrid” approach you have mentioned is indeed one of if not the best mehtod of rapid body recompositioning.
At the end of the day, energy balance has yet to be overturened as the best way to loste “weight”.