“The Nutty Professor” worked for a number of reasons. For starters he did not make the protagonist, Sherman Klump, into a buck-toothed nerd à la Jerry Lewis, but rather a painfully shy and brilliant man who was all too aware of his physical appearance handicap, namely, being grossly obese. A desperate Klump concocted a chemical formula which he hoped would make him young and dashing. The result was the Klump morphed into the handsome but obnoxious gent named Buddy Love. Sherman and Buddy wound up competing for the affections of the lovely graduate assistant played by Jada Pinkett, with our corpulent hero winning the day.

“The Nutty Professor” had a sweet quality to it, but it also had a raucous, witty touch as well. Eddie Murphy created not only Sherman, but also other members of the Klump family to enhance the comedy. The other Klumps helped vary the mix, but the primary focus was on the relationship between Sherman and Buddy. The key problem in “The Nutty Professor II: The Klumps” as is clear from the film’s title, is that Murphy tries to give equal time to the rest of the supporting Klumps (he plays all of the here, as he did in the original). That turns out to be a critical mistake, since they are at best marginal supporting characters. The Sherman-Buddy conflict is downgraded here to almost an afterthought until a frantic and desperate finale.

“The Nutty Professor II” starts out like gangbusters with two sidesplitting scenes. In the opening frame, we see Sherman having a nightmare about his wedding day with a very attractive colleague, a biology teacher named Denise Gaines (Janet Jackson taking over for Jada Pinkett). Once again, he and Buddy are duking it out for a lass’s affections. Shortly thereafter Sherman and the rest of the heavy-set Klumps “attack” an inexpensive all-you-can-eat buffet. After the first twenty minutes, however, it all goes downhill.

Whereas Sherman invented a liquid brew that made him slimmer in the first film, here he invents a youth potion. The only thing this does is allow Eddie Murphy to make numerous tired Viagra jokes as well as to take mean-spirited jabs at senior citizens.

In another plot contrivance, Buddy Love comes back to life, but because of a botched experiment in the lab involving a dog, Buddy returns with the instincts of a canine, merely laying the ground for countless flatulence and defecation jokes.

It is painfully obvious that after an hour, the filmmakers ran out of ideas and helplessly tried to pad the running time. Eddie Murphy, Janet Jackson, and the supporting cast, which includes Larry Miller as the unctuous dean at Klump’s college and Kathleen Freeman as a crazed neighbor of the Klump’s, work hard, but they can’t save this film.