Professor Ruth Burke, Dean of the Faculty of Health Sciences at Ariel University in Israel, has been studying this topic for many years. According to Prof. Burke, a considerable amount of traits and diseases are developed on account of someone's genetics - including obesity.
Yet the tendency towards obesity isn't solely up to genetic hand me downs through someone's parents, it also comes from environmental factors such as nutrition and exercise as well.
To date, hundreds of genetic influences have been found that increase the chances of gaining weight in high-caloric intake environment, yet no influences have yet been found that simply increase the chances of someone gaining weight.
This means that although a genes do have a role to play, they're not the sole reason for someone's tendency towards obesity, as environment factors need to be involved as well. Nutrition is an obvious is an obvious contender in contributing environmental factors towards obesity.
Prof. Burke, who also lectures in Ariel University's Department of Nutritional Sciences and does research on genetics on nutrition, states that customized nutrition based off someone's innate genetic structure is an option that exists in private companies. According to Prof. Burke it is an innovative and developing field with potential but also great complexity.