Total body potassium (TBK) data calculated from longitudinal measurements over 18 y of 40K by whole-body counting of 564 male and 61 female healthy humans in a 2-pi liquid scintillation counter show little change in females younger than 50 y compared with males of those ages. Males show less TBK from 41 y onward as they age, with most rapid rate of loss between 41 and 60 y. Females have a rapid loss of TBK when they are older than 60 y; the loss is at a greater rate than that of males. Percent total body fat calculated from total body weight and lean body mass (LBM) derived from TBK document greater adiposity in females at all ages except ages 51-60 y when females are similar to males in change in percent fat per year per centimeter.

One hundred sixteen male volunteers between the ages of 32 and 62 years (mean age 46) consumed two whole fresh eggs daily in their customary diets for 3 months and also eliminated eggs for 3 months before or after eating eggs. The men had had normal-range serum cholesterol and triglycerides for the past 7 years. Four-day food records kept by them in each experimental period were assessed for nutrient intake. A Latin square design allowed analyses for season and sequential effects on serum lipids. The serum cholesterol and triglyceride levels at the end of 6 months were compared with their initial levels on customary free choice diets as well as their levels after the first 3 months of study. No significant increase in mean serum cholesterol was found nor was there a significant association of dietary cholesterol intake with either serum cholesterol or triglyceride.

The old adage, "You are what you eat," is not always reliable, as demonstrated in this mixed-longitudinal study of men that began in 1969. Mean values of percent body fat, total body potassium (TBK), and total serum cholesterol (SCHOL) did not show changes that correlated with any studied nutrient from repeated 4-day diet records. Mean blood pressure increased with increased body weight as age increased. High-density lipoprotein cholesterol decreased when polyunsaturated fat intake increased. The men had decreased mean height, TBK and increase in percent body fat as age increased. Food energy intake decreased equally from carbohydrates, protein and fat as age increased. Large standard deviations of mean values of measured parameters document heterogeneity of these subjects. A subset of 144 male cohorts was studied serially for 20 years in time-age, cross-sectional and longitudinal series. As they aged, height and TBK decreased (p < or = 0.05), percent body fat and blood pressure increased (p < or = 0.04) and SCHOL had no significant change. Intake of all nutrients decreased significantly (p < or = 0.03) longitudinally and with time, showing a time effect.

The mean values for serum total cholesterol for 47 males, aged 32 to 62 yr who, over a 10 1/2 month study ate, within a self-selected diet, beef as the only meat for 3 months, poultry and fish for 3 months, and pork for 3 months showed no statistically significant difference, whereas 17 of 29 females of the same age who participated in the same study had borderline statistically significant differences in mean values (p less than 0.055). When data from all subjects were considered together, no statistically significant changes in mean serum total cholesterol or serum triglycerides were noted, but there were significant changes in mean high-density lipoprotein cholesterol values, both upward and downward. The important results of this study are documentary to the lack of influence of "meat" and its fat on effecting a significant change in serum total cholesterol within a self-selected diet.

1) importance of using serum holotranscobalamin TCI and TCII as markers of cobalamin deficiency, 2) necessity to use documented quantitative components of dietary intake if strong comparisons are to be made among quantitative values of serum or plasma homocysteine, folate, cobalamin, and nutrients in food intake.