Focus on food > fads
After reviewing the scant data from the present HCG diet
and the one in the 70s, i still believe a reproductive endocrinologist can comment best on effects of hcg.
Wrt being on the diet when ttc or pregnant, i say avoid lo-cal. There are few times in life when diet matters more. The goal is to have the healthiest body for the healthiest baby. Eating 3 toxin-free balanced meals with snacks is best.