Thinnergy - For Thinness and Energy is a fictional diet book, giving information on how nutrition can increase a person's energy. Marcy recommends it to Peggy when she fears that Al does not find her attractive anymore.
Marcy describes the book's content as not just a diet plan but "a way of life". It lists "bad foods" that drain a person's energy and "good foods" that add to their energy to help them eliminate their "bad foods" so they wake up with more energy (and go to bed with more energy, too, as Marcy adds). Draining foods mentioned include potato chips.
The health plan suggests a carrot for breakfast, as it has a natural sweetness, and natural spring water with everything. Suggestions for supper include grapefruit, kale and broccoli, and salad, as it has riboflavin, folacin, iron and magnesium. The plan also includes a Radish Day.
The book adds that the participants might go through grouchy periods as the toxins leave their bodies and suggests to stop and share a nice memory whenever they feel an argument coming on. (This does not work for Peggy and Al.)