Most men can expert to reach their peak weight between the ages of 35 and 44, but women keep growing heavier until they are between 55 and 64, a government survey shows.

The study of the National Center for Health Statistics also found that men and women weigh a few pounds more than their counterparts did in a national survey conducted in the early 1960s.

Alice Haywood, a spokeswoman for the center, said yesterday it is not clear why a woman's weight does not turn downward until she reaches her mid-50s or later.

Men who are 5-foot-7 or shorter don't reach their peak weight until the ages 45 to 54, or a decade later than men of average height.

While men who are 5-foot or taller shed pounds after reaching their top weight between 35 and 44, they gain some, but not all, of it back between 55 and 64 before losing weight again.

The average adult man stood 5-foot-9 and weighed 172 pounds. The average woman was a shade over 5-foot-3 1/2 and weighed 143.

People were measured for height with their shoes off. Weight figures include an estimated half-pound of clothing.

In the new survey, based on health examinations of more than 13,600 persons from 1971 to 1974, women under 45 weight 4.7 pounds more on the average than women checked in 1960 to 1962. After age 45, the difference was less than a pound in the two surveys.

Men under age 45 were 3.8 pounds heavier and those 45 and older weighed 4.8 pounds more than their counterparts of a decade ago.

The center's report said, "Average weights of men increase rapidly until the age group 25-34 . . . [and] then flatten out."

Women's weight climbs rapidly until 35 to 44, and then increases slowly until it starts dropping as women approach their retirement years.

The center released tables showing the average weight by height for adults at different age groups. It said the figures were "not presumed to indicate 'ideal' or 'desirable' weight," but simply reflected what the survey found.