BY intent and by design, the Ten-State Nutrition Survey (TSNS) of 1968-1970 was concerned with both undernutrition and overnutrition. One concern was caloric and nutrient insufficiency and the effects of inadequate nutrition on growth and development. A second concern was caloric excess, as reflected by the level of fatness, and especially the prevalence of obesity, in different socioeconomic groupings and in different population segments. In the design of the TSNS, it was obvious that weight alone—or even weight relative to height—was an inadequate measure of fatness. A child might be "overweight," yet of less than average fatness; another child or adult might be underweight, yet actually obese. Accordingly, two fatfold measurements (commonly but improperly called "skinfolds") were incorporated into the anthropometric program. One benefit of the TSNS may be seen in the fact that we now have nine-decade triceps or subscapular fatfold data on more than 40,000 individuals; nearly one half of them are American Negro (i.e., black), for whom scant data were previously available. A second benefit is that these new data are sufficient in scope to describe lifelong changes in fatness, including some phases not previously known in detail. A third benefit is the socioeconomic partitioning of fatness, showing both an economic-related fatness increase in the male at all ages and an economic "reversal" of fatness in the female at adolescence and beyond. The TSNS was conducted on a household and family-line basis, including both parents and their children.1 So we have the opportunity to compare true family-lines, parents and their children, brothers and sisters, and husbands with wives.