The same amount of alcohol will be more diluted in a larger individual because this person has a bigger surface area in his body and his bodily fluids are greater than those of a small person's. With this the liver and pancreas' capacities to release enzymes necessary to breakdown the alcohol is more efficient and comes in bigger dosages. However, it should be noted that regardless of the effects of this in the body, a person should still know how to regulate alcohol intake as this has other known effects in the body (e.g. mentally and physically).
Because the larger individual is more likely to be heavier and bigger in general - with that also carrying more weight. Because alcohol gets diluted in the body, it will become more diluted in someone who is bigger compared to someone who is smaller - simply for these reasons the same amount will have less of an effect in a heavier individual.
