a) I tutor chemistry. Sharon Welcher’s book is the best on the market. Harnick on Ave. J, a”h, once sold it. Now, I believe Barnes and Noble in Park Slope sells it.
b) Weight Watchers is good, and offers a lot for the non-CY kosher keeper (they’re foods are available widely and almost are all OU). Regardless, eat lots of fruits and veggies and limit bread to Shabbos. Allow yourself “cheats” as your oneg shabbos, but watch what you eat the rest of the week.