General

Looking at it from a scientific point you would think that hangovers would be easier to deal with since the higher body weight the less drunk you get in the first place. I suppose if you measured to the same level of intoxication it might not matter as much but since your body weight is higher it would deal with the alcohole easier and the hangover if any should be lessened. This is just a theory though since I haven't tested anything. It would be interesting to test though.

you are more likely to have a hangover as an obese person. this is because your body is composed of less water by proportion when you are obese. the metabolic waste produced from breakdown of alcohol is water soluble, therefore obese people concentrate these products relative to non-obese people and are more likely to have hangovers due to increased concentrations of acetaldehyde and be dehydrated morning after.

obese people can help avoid hangovers by drinking water before going to bed after drinking, and some sugar is also a good idea since alcohol activates a pathway that sends sugars and fats into molecular building pathyways rather than allowing them to be consumed for energy production. the resulting low sugar, or hypoglycemia is also unpleasant and contributes to the hangover.