Eating patterns and dietary composition in relation to BMI in younger and older adults

Objective: To compare relative associations of eating patterns and dietary composition with body mass index (BMI) in younger (aged 20-59 years, n= 1792) and older (aged 60-90 years, n = 893) participants in the Continuing Survey of Food Intakes by Individuals, collected 1994-1996. Methods: Data from two 24-h dietary recalls from individuals reporting physiologically plausible energy intake (within +/- 22% of predicted energy requirements, based on previously published methods) were used. Results: Mean reported energy intake was 96 and 95% of predicted energy requirements in younger and older subjects, respectively. Older subjects were less likely than younger subjects to skip a meal, but snacking was common in both age groups. Fiber density was significantly higher in the older group. A higher BMI in both age groups was associated with a higher total daily energy intake, and higher energy intakes at all eating occasions. In both age groups, eating frequency was positively associated with energy intake, and eating more than three times a day was associated with being overweight or obese. In the younger group but not the older group, a lower fiber density coupled with higher percentage of energy from fat was independently associated with having a higher BMI. Conclusions: While no one eating occasion contributes more than any other to excess adiposity, eating more often than three times a day may play a role in overweight and obesity in both younger and older persons. A reduced satiety response to dietary fiber in addition to lower energy expenditure may potentially further contribute to weight gain in older persons.