Study evaluated siblings over 36 years to try to explain the role of genetics, environment and lifestyle in the predisposition to gain weight. The research, published in the journal Obesity, is the first of its kind to decipher in a pair of twins with large differences in weight between each other.

The author of the study, Bram J. Berntzen, from the Institute of Molecular Medicine of Finland, assures that this “novel approach” opens doors to discover the factors that protect or predispose people to weight gain.