This study used balance theory to illuminate the relations of eating-related attitudinal consistency between self and friends to psychological well-being and eating behaviors. It was hypothesized that attitudinal inconsistency, relative to consistency, would predict lower well-being and poorer eating habits. A population-based sample of 2287 young adults participating in Project EAT-III (Eating Among Teens and Young Adults) completed measures of psychological well-being, eating behaviors, and eating-related attitudes from the standpoint of self and friends. Of participants who cared about healthy eating, those who perceived that their friends did not care about healthy eating had lower well-being and less-healthy eating behaviors (fewer fruits and vegetables and more sugary beverages per day) than those who perceived that their friends cared about healthy eating. Conversely, among participants who did not care about healthy eating, those who perceived that their friends cared about healthy eating had lower well-being and less-healthy eating behaviors (more snacks per day) than those who perceived that their friends did not care about healthy eating. In accord with balance theory, young adults who perceived inconsistent eating attitudes between themselves and their friends had lower psychological well-being and generally less-healthy eating behaviors than people who perceived consistent eating attitudes.

We examined the association between sleep duration and BMI in young adults, and, specifically, in possible gender differences. The population-based sample included 955 young men and 1051 young women (mean age = 25.3 years, s.d. = 1.7) who participated in Project EAT-III (Eating and Activity in Teens and Young Adults)-III. In 2008-2009, study participants completed a survey, on which they reported their weight, height, and typical bed and awakening times. Gender-specific regression models estimated cross-sectional associations between sleep duration and weight status, adjusting for age, race, SES, family structure, depressive symptoms, physical activity, and sedentary and dietary behaviors. In multivariable-adjusted linear regression models, an hour increase in sleep was associated with a -0.38 (-0.70, -0.048) BMI in men. Men who slept <7 h had a 1.4 unit higher mean BMI (27.9; 95% confidence interval (CI): 26.9, 28.9) than men who slept 7-9 h/day (26.5; 95% CI: 26.1, 27.0). Prevalence estimates of overweight (BMI ≥25) and obesity (BMI ≥30) were also inversely associated with sleep duration among men. Sleep duration was not associated with BMI, overweight, or obesity in women. Among women, but not men, there was a statistically significant positive association between trouble falling or staying asleep and mean BMI. Sleep may be an important modifiable risk factor for obesity, particularly in young adult men.