New York: If you are able to steadily maintain a lean body all your life, you are likely to live longer in comparison to those who have since childhood a heavy body that has got heavier during middle age, new research reveals. The findings showed that people who had a heavy body shape from their childhood and also put on weight during their middle age are at highest risk of mortality with a 15-year risk of death being 19.7 percent in women and 24.1 percent in men. In contrast, those who remained stably lean throughout life had the lowest mortality, with a 15-year risk of death being 11.8 percent in women, and 20.3 percent in men. "Our findings provide further scientific rationale for recommendations of weight management, especially avoidance of weight gain in middle life, for long-term health benefit," said Mingyang Song, doctoral student at Harvard University in the US. In addition, high body mass index (BMI) in adulthood can also increase the mortality risk. Among the study participants, lowest mortality was found in the BMI range 22-23 among including healthy non-smokers and excluding people with prevalent diseases. Obesity has become a public health crisis in most countries worldwide. But, these results indicate the importance of weight management across the lifespan, the researchers noted. For the results, published in The BMJ, the team of researchers tracked the evolution of body shape and associated mortality in two large cohort studies. Body shape of 80,266 women and 36,622 men were studied at ages 5, 10, 20, 30, and 40 years. Their body mass indexes were measured at age 50, and were followed from age 60 over a median of 15-16 years for death. In a second study, the team carried out a large meta-analysis of 230 prospective studies with more than 3.74 million deaths among more than 30.3 million participants. They analysed people who never smoked to rule out the effects of smoking, and the lowest mortality was observed in the BMI range 23-24 among this group.