it mostly consists of mixed vegetables, instant HPW mix, some fruits (blueberries, banana, apple), glideraid once or twice a week.
While it is true that instant HPW (from exotic nutrition) does not contain Wombaroo High Protein Supplement as it name tries to imply, I do not think it has a lot of fillers. It may or may not be a good diet - it is still relatively new so there are not long term observations of gliders fed this product long term.
If it is SIMILAR to the original HPW - is may not be very high in calcium and like original HPW it may have a ratio about 1:1 or roughly equal amounts of calcium and phosphorus. If so, feeding the frozen mixe vegetables every day may be too much phosphorus - throwing the overall balance of the diet in to a lower amount of calcium than phosphorus.
Try offering a wider variety of fruits and vegetables and include some higher calicum foods a few nights each week. Spinach or other dark green vegetables, bok choi, okra, broccoli, papaya would be good to include.