BY DESIGN : THE FALL COLLECTION / CALIFORNIA : Small Helpings : The designers who do show their fall lines in L.A. tend toward overly easy, casual dressing. Such a restricted diet leaves fashion-watchers hungry.

Where’s the beef? That was the question posed by many who watched two Los Angeles fall fashion shows last week. And they weren’t talking about the food.

The buffets were bountiful, as usual, on Friday evening for the New Mart’s show in the building’s high-tech theater. And again on Saturday night when the rival California Mart took over the Variety Arts Theatre for its grandly titled “Legends.”

But the dearth of designers--and sometimes designs--left fashion addicts feeling undernourished. Traditionally, the California talent has put more oomph into exhibiting spring collections. Yet every year, optimists hope for a better fall feast.

Once again, the show at the New Mart--the landmark Downtown building that has lured away such former Cal Mart tenants as Jessica McClintock and David Dart--was bland and heavily weighed toward casual comfort.

Which means McClintock, mistress of dressy dressing, didn’t show, but Dart, master of office and weekend ease, did. His palette was subtle and soft, often with gray and white stripes or plaids mixed with solids in cozy fabrics that appeared in layered country ensembles.

The evening was loaded with stripes, from misc.’s hip narrow-legged pants--worn with a shapely little shirt jacket--to PTA-ready red dresses with striped jackets by J’Coute Cher all the way down to unisex long johns by P.J.’s Salvage.

At the Variety Arts Theatre came proof that short shorts, or hot pants, are, well, still hot. Biya took the sophisticated road with a dark gray tweed pair worn over opaque hose and under a cavalry-style long coat. Yo Kwon’s take was more humorous: hot pants printed with images of Mona Lisa and combined with a single Mona on the front of a sexy, shiny cropped top. And Van Buren chose pinup cult-figure Betty Page as its finale legend, dressing her in black leather hot pants with a leopard bustier.

It was also a big night for satin. There were solid satin suits and dresses, long and short, in the L. Bates collection. Naomi Hasak did a long, sleeveless dress in a rose print on black that could do night or daytime duty. And Biya dressed her finale legend, Joan Crawford, in a vanilla-colored satin gown with a crinkle skirt and sleeveless V-neck satin top.

Moschery started the steady parade of suits with chic, short silhouettes in a black-and-white windowpane plaid trimmed with narrow black patent belts and patent pocket flaps. A mustard-colored wool “suit” turned out to be a short jacket over a sexy dress with spaghetti straps and a leopard bra.

Many pantsuits featured narrow trousers that stopped well short of the ankle. Jackets were shapely, often short and always well tailored--with eye-catching buttons and artistic buttonholes used as decoration.

No one did suits--or dresses, or whatever--better than Van Buren by Maggie Barry and Ty Moore. The fun-loving team, who took their post-finale bows dressed in a kitschy mix (a beanie and Dr. Pepper T-shirt for him, a leather aviator outfit for her), stole the show.

Their novel prints, inspired by ‘40s newspaper photographs, appeared on long dresses and on a jacket topping an impeccably tailored short gray dress.

For Moore and Barry, the show was a chance to make a trial run with 40 of the collection’s 85 pieces. Next week, they will show for the first time in New York, in a slot recently vacated by Mary McFadden.