As with Hidden Pictures (1986) and Sleepwalking (1982), Wolitzer's chosen an intriguing topic for her new novel: two children--Erica and Opal Engels--who grow up watching their famous overweight mother crack up studio audiences on late-night talk shows. To the children, their comedienne mother, Dottie Engels, is a ""kind of Brunhilde figure, armored and huge and fearless."" Their father exists only in snapshots taken before his separation from Dottie--a thin, pale, barely corporeal man who forgot them once the divorce papers were signed. Even though Dottie calls them in their palatial N.Y.C. apartment every night from the coast, sends them to a posh private school, hires comic hopefuls to amuse and babysit them, and cuddles them in her capacious lap whenever her schedule permits, the girls grow up troubled. Erica, the older, gets fat just like mom, only unfunny, confused, clinging to a loveless relationship with a drug dealer named Jordan Strung. Opal, thin and popular, identifies too closely with Dottie, dropping out of Yale when her mom's career hits the rocks. For a while, Dottie manages by promoting a line of clothing for obese women, but then a heart attack forces her to decide between dying or checking into a California clinic to slim down and shape up. Ultimately, it's Opal and Erica who get her to make the right choice, and along the way, they also find themselves through relationships with helpful men. This shadowboxes with strong themes and maintains a finely balanced seriocomic tone. But Wolitzer's metaphor for celebrity--obesity--consumes the whole, so that, finally, the book is more about fat than fame and, thus, disappointing.