Given the short time frame, this is likely due to changes in diet or activity level rather than inescapable genetic destiny.
Those are not the only possibilities. For example, it’s been hypothesized that obesity might be linked to some now-ubiquitous chemical exposure that messes with human hormone balances. If it’s a novel environmental factor, some people might be especially genetically susceptible or resistant to the effect.
Those are not the only possibilities. For example, it’s been hypothesized that obesity might be linked to some now-ubiquitous chemical exposure that messes with human hormone balances. If it’s a novel environmental factor, some people might be especially genetically susceptible or resistant to the effect.
The most known ubiquitous chemical that messes with human metabolism is sugar.