Finally, there's a scale that weight-conscious Americans can do something about. The furniture scale.

It seems our living rooms and dens are overstuffed with furniture too wide, too deep and too heavy for the surroundings, and it has some interior designers ready to put homeowners on a decorating diet.

"The most important thing in a room is scale and proportion, and if you don't get that right, no matter how beautiful the furnishings are it's not going to work," laments Carol Swetman, ASID. "It's not easy these days when some of the rooms are so large and the ceilings so high."

Big homes with big spaces are often singled out for blame. With great rooms formed from a coalition of dens, family rooms and kitchens, it's no wonder homeowners see big as better. Manufacturers made sure consumers got furniture to match such outsized construction as less frequently used formal rooms such as living or sitting rooms were downsized.

Furniture selection is far from a one-size-fits-all proposition.

That furniture is a potential mismatch for a room is a foreign concept to most homeowners. Ill-fitting furniture and accessories can quickly produce a room that appears out of kilter.

How-to conversations seldom dwell on issues of scale, thus size and volume rarely turns up on homeowner radar screens.

In fact, Swetman says she has "never had a single client mention it (scale). As an interior designer, I'm thinking of scale and proportion and they're thinking of style."

So when does furniture come close to tasteful size boundaries? interior designer Robert Schoeller estimates sofas cross the line when depth approaches 40 inches. In his view, a more body-friendly "lighter scale depth" is 34 to 36 inches. The upper boundary for chairs is 38 inches deep while an ideal depth is in the 36-inch range.

Compounding the depth issue is thick, dense furniture arms, and chunky backs that exacerbate the sense of enormity.

Yet no hard and fast rule exists that says "this is too big and that is too small." Deciding factors are room size, including height. However, the unfortunate tendency is to assume spacious rooms must be filled to the brim with large pieces, and small spaces limited to dainty items.

Scale may also work against comfort. Both Swetman and Schoeller cite instances of residents seemingly swallowed up by couches and easy chairs.

When furniture is more apt for Hercules than Uncle Harry, things have gone too far, says Swetman, who believes monstrous pieces make the user "feel like a child if their feet can't reach the floor."

The advice is to test furniture just as you would lie on a showroom mattress. Sit or slouch in it for several minutes. Measure and plot the dimensions of the furniture and your room on quarter-inch graph paper. Furniture that seems fine in a furniture gallery may be too massive once delivered to your home. Ask store designers for advice or consult with an interior designer.

You may see what Swetman calls "human scale furniture" show up in stores. "The pendulum swung too far toward big furniture," she says. "We may start to see it swing the other way."