Key Takeaways
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Healthy eating can boost heart health even if a person doesn’t lose weight
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About a third of participants in three major nutrition trials didn’t lose weight
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Nonetheless, a healthy diet improved their cholesterol, belly fat and hunger
MONDAY, June 9, 2025 (HealthDay News) — Don’t get frustrated if switching to a healthy diet doesn’t result in any weight loss – your heart is thanking you nonetheless, a new study says.
These included an increase in “good” HDL cholesterol, lower levels of the hunger hormone leptin, and less belly fat putting pressure on internal organs, researchers report.
“We have been conditioned to equate weight loss with health, and weight loss-resistant individuals are often labeled as failures,” said lead researcher Anat Yaskolka Meir, a postdoctoral research fellow in epidemiology at Harvard T.H. Chan School of Public Health.
“Our findings reframe how we define clinical success,” Yasolka Meir said in a news release. “People who do not lose weight can improve their metabolism and reduce their long-term risk for disease. That’s a message of hope, not failure.”
For the study, researchers analyzed data from 761 people with obesity in Israel who participated in three landmark workplace-based clinical trials involving nutrition.
In each trial, people were randomly assigned to adopt and stick with healthy diets for between 18 and 24 months.
Results showed that nearly one-third of the participants did not lose any weight.
However, people who were resistant to weight loss still showed many of the same improvements as those who did drop pounds, researchers said.
“These are deep metabolic shifts with real cardiometabolic consequences,” Yaskolka Meir said. “Our study showed that a healthy diet works, even when weight doesn’t shift.”
The study also found 12 specific sites where a person’s genetics can strongly predict their ability to lose weight.
“This novel finding shows that some people may be biologically wired to respond differently to the same diet,” senior researcher Iris Shai, an adjunct professor of nutrition at the Harvard T.H. Chan School, said in a news release.
“This isn’t just about willpower or discipline — it’s about biology,” Shai said. “And now we’re getting close to understanding it.”
SOURCE: Harvard T.H. Chan School of Public Health, news release, June 5, 2025
What This Means For You
People should consult their doctor or a nutritionist on ways to improve their diet.
