There are several questions regarding efficiency of quest bars in hcg diet. Sorry to say but it is better to stay out of this product. WHY? There are many people who have noticed apparent rise in their blood sugar levels that might also increase weight. While it is okay to boost blood usgar levels naturally, Quest bars contain Erythritol and the usual sucralose which is additional flavors and sweeteners that might boost sugar levels and definitely not in a good way.
But then there are few who have tried it in Phase 3 and 4. However, the topic is still murky.
Better to stay out of it and stick with the hcg protocol.