Weight loss and heart disease

Specifically, if young people who are overweight loss weight in middle age, does their risk of heart disease go down.

Answer: yes.

Previous studies have linked being overweight as a teenager or young adult to deadly consequences later in life, including an increased risk of heart disease. But it was unclear if the risk was higher simply because heavy teenagers become heavy adults, or because being overweight or obese as a young adult causes irreversible damage.

... when the researchers factored in middle age, adjusting for the subjects’ weight at that time, they found that the risk changed. The men who started college overweight or obese but were of normal weight in middle age no longer had a higher risk of dying of heart disease.

Body mass index in middle age was a strong predictor of dying of heart disease, the study showed. Being overweight in middle age increased the risk 25 percent, and being obese raised it 60 percent.