Nutrition Editor
Sarah Chen is a Registered Dietitian Nutritionist with a Master's in Nutritional Science from UC Davis. With 12 years of clinical experience, she specializes in metabolic health and evidence-based dietary interventions. Her work has been cited in the American Journal of Clinical Nutrition.
The sun synthesizes vitamin D in human skin only when it hits at a steep enough angle. North of 35 degrees latitude, that angle is unavailable for months at a time — which changes everything about how supplementation should be approached.
Roughly 70% of the body's immune cells reside in the gut. The trillions of microbes living alongside them are not passive tenants — they actively calibrate how the immune system distinguishes threat from background noise.
Intermittent fasting has generated enormous enthusiasm and equally fierce skepticism. The clinical evidence lands somewhere in between — and reveals important nuances about who benefits most.
The recommended daily protein intake varies dramatically depending on who you ask. Here's what the science actually says about optimal protein consumption.
Decades of research have made the Mediterranean diet the most evidence-backed eating pattern in nutrition science. Here's what the latest studies add to the picture.
Body Mass Index has been the go-to metric for decades, but emerging research suggests we need a more nuanced approach to measuring health.