After hanging on the doctor's office wall for 24 years, the traditional height-and-weight charts have been changed again, revising "desirable" weights upward by as much as 13 pounds in some cases.

The Metropolitan Life Insurance Co. of New York has been putting out height versus weight charts since 1942, and they have become a standard wall decoration in doctors' offices.

The charts are based on data from 25 insurance companies and 4.2 million people whose health has been tracked for years. The charts mark the "desirable" weights of those with the greatest longevity.

Doctors and the insurance company said that because the weights have been revised upward does not mean that fatter is better. It only reflects a change in the risk factors for Americans, especially those for Americans who are slightly heavier.

In addition to changing the height-to-weight ratios in the tables, the insurance company doctors said they no longer call the weights in the chart "ideal or desirable," since those adjectives may be misleading.

Dr. Paul S. Entmacher, vice president and chief medical director for Metropolitan, said the weights in the chart "do not necessarily indicate weights that will reduce the likelihood of illness, nor are the weights those . . . at which a person looks his best." He said they are merely statistical ranges inside which the longest lived people fit.

He said the weight gains in the chart do not mean people "have a license to gain. It simply indicates that many people may have fewer pounds to lose."

The last time the insurance companies compiled health data and Metropolitan drew a height-and-weight chart from the information was 1959.

The 1983 tables have an average increase of 13 pounds, or 10 percent, for short men; 7 pounds, or 5 percent, for medium height men; and an increase of 2 pounds, or 1 percent, for tall men.

For short women, the average increase is 10 pounds, or 9 percent; for medium height women, 8 pounds, or 6 percent; and for tall women, 3 pounds or 2 percent.