Obesity affects heart health at every stage of life, from childhood through adulthood. On World Obesity Day 2026, PHRI is highlighting research that is helping to better understand how obesity develops, how it increases cardiovascular risk, and what approaches may help reduce that risk over time.
Led by scientist Jorge Wong, the BRAVE trial is examining whether bariatric surgery is a safe and effective way to reduce the risk of death and major cardiovascular events in people with obesity and established heart disease, compared with medical weight management.
PHRI researchers are also studying obesity prevention earlier in life. The Living Green and Healthy for Teens (LiGHT) trial, led by scientist Zubin Punthakee, is evaluating whether a health app can help youth and their families adopt healthier habits related to physical activity, eating, and sleep, which may reduce the risk of obesity and its complications.
“Health apps can reach a broad audience and have the potential to impact health behaviours at a population level,” Punthakee said.
Evidence that changed how obesity risk is understood
INTERHEART, a major landmark trial led by Salim Yusuf, founder and emeritus executive director and senior scientist at PHRI, examined risk factors for heart attacks in 29,972 participants from across 52 countries.
The study found that nine easily measurable and modifiable risk factors account for more than 90 per cent of the risk of a first heart attack worldwide, across regions and major ethnic groups. It also showed that abdominal obesity, measured using waist‑to‑hip ratio, is a stronger predictor of heart attack than body mass index. These findings shifted attention away from weight alone toward fat distribution and metabolic risk.
Research that starts early
PHRI researchers also investigated how obesity develops early in life. Studies such as FAMILY and START explored how environmental, metabolic, genetic, and early‑life factors contribute to excess body fat and future cardiovascular risk.
PHRI is involved in national initiatives such as the Canadian Pediatric Weight Management Registry (CANPWR), which followed children enrolled in weight management programs across Canada to better understand obesity‑related health conditions over time and differences in how children respond to current treatments.
DECCO, led by associate senior scientist Katherine Morrison, examined cardiovascular risk factors including blood pressure, cholesterol, and blood sugar response in children and adolescents who are overweight, and how these factors change during structured lifestyle programs.
“Our research addresses important gaps in the understanding of obesity that can help inform clinical decision‑making and health‑care guidelines,” said Hertzel Gerstein, PHRI interim executive and senior scientist. “What sets PHRI apart is our use of innovative research approaches to better understand the causes and impact of obesity across populations, ages, and backgrounds, helping to open new opportunities for prevention and treatment.”
