Drink coffee and tea, no soft drinks - fat.
My mother, drinks tea - fat
DP, drinks tea, coffee and soft drinks - slim
Next door neighbour, no hot drinks - morbidly obese
NDN's boyfriend, no hot drinks - morbidly obese
Old neighbour, no hot drinks - supermorbidly obese
Colleagues x 2, drink tea and coffee - very slim
Boss, drinks tea and coffee - underweight
Line manager, drinks tea - obese
90-odd% of the teenagers at work, soft drinks, some tea, some coffee - slim
<5% of teenagers at work, no hot drinks - not as slim
<5% of teenagers at work, hot drinks - not as slim
It's as if there's no real correlation, other than if they drink (and eat) more calories than they need at whatever temperature they prefer.