By Kat Procyk
Photography by Joshua Franzos
Samaneh Farsijani, assistant professor of epidemiology, University of Pittsburgh School of Public Health, has a broad fascination with aging—specifically how every day, modifiable behaviors like exercise and nutrition can shape the trajectory of health, resilience and independence as people grow older.
However, she doesn’t necessarily agree with the one-size-fits-all approach used by current dietary guidelines.
These guidelines focus mostly on nutrient composition or dietary patterns and don’t consider important factors like meal timing, which is crucial for maintaining circadian rhythms and metabolic health.
“Many dietary guidelines are intended for broad populations and do not fully address differences across age groups, sex or race,” Farsijani said. “The research I’m doing is primarily focused on developing age-specific dietary recommendations to promote healthy aging. What I see missing in our current guidelines is not just what specific foods and nutrients we need depending on how old we are, but when we should eat.”
On Friday, April 10, Farsijani will present “A Multidimensional Precision Nutrition Approach to Healthy Aging” as part of the 2026 Senior Vice Chancellor’s Research Seminar Series. (Join the lecture here.)
In her research, Farsijani discovered a significant difference in the timing of food and beverage consumption across age groups. Older adults tend to eat breakfast and final meals earlier, while younger adults tend to eat more at night. Her findings supported that older adults have a narrower eating window, and this shorter window was associated with lower muscle mass, strength and leg power in older adults.
In recent years, time-based diets such as intermittent fasting and time-restricted eating have become increasingly popular, yet little research has examined how these patterns affect older adults. Fasting, for example, is widely promoted for weight loss, metabolic health and longevity, but Farsijani’s research raises questions about whether these approaches are appropriate for older adults.
“Most evidence so far comes from animal studies and short-term human trials in younger adults, so we don’t know whether these patterns are safe or beneficial for other population subgroups, like older adults,” Farsijani said. “They may even be harmful for some individuals. Our findings suggest that longer fasting periods may not be ideal for older adults.”
Farsijani realized the need for more personalized diets during her dietic internship in different hospital settings and community clinics. Intensive care and major surgical patients typically have higher protein needs, and dietitians adjust their protein intake to support healing and recovery. Farsijani noted that in some cases patients’ healing was so rapid that physicians asked what food was prescribed.
“Seeing how strongly the body responded when nutrition was tailored to a medical condition really shaped my interest in the field,” Farsijani said.
Currently, Farsijani is using observational studies for her research, but her next step is to conduct clinical trials to establish a causal relationship between diet and health outcomes.
“Clinical trials are the gold standard for advancing nutrition science,” Farsijani said. “To meaningfully improve dietary guidelines, we need evidence that goes beyond associations and actually demonstrates how specific dietary patterns influence real health outcomes. When that level of evidence is strong, it gives us a far better foundation for translating research into practical, trustworthy guidelines.”