Weight loss is a subject that is on the mind of almost every human being worldwide. Most people try and lose weight as a means of improving their appearance, increasing their energy levels, or decreasing their cholesterol. While these are all okay reasons to want to lose weight, there remains one more reason that stands above the rest—the fact that excess body fat can actually shorten your life span by shortening your telomeres.

Telomeres are the DNA sequences on the extreme ends of the chromosomes that aid the cell in cell division. Telomeres lose a little bit of DNA every time the cell divides and eventually they become so short that the cell stops dividing, stagnates, and dies. The longer a cell’s telomeres are, the longer the cell can continue dividing.

Shorter telomeres have recently been linked with high body mass indexes. A study published in the British medical journal The Lancet followed 1,122 women ages 18 to 76 and discovered that the more obese women had an average telomere length 240 base pairs shorter than the thinner women. The science shows that between two women of the exact same chronological age, the one with the lower body mass index is likely to be younger on a molecular level because her telomeres are longer.

Obesity has already been linked to many age-related diseases like cancer and heart disease. The correlation between high body fat, shorter telomeres, and age-related diseases may serve as a new-found motivation to hit the gym to try and drop a few pounds.