A long-term health study that followed a group of people who were age

I am seeing some confusion between (A) and (C), so let's see if I can resolve that.

A long-term health study that followed a group of people who were age 35 in 1950 found that those whose weight increased by approximately half a kilogram or one pound per year after the age of 35 tended, on the whole, to live longer than those who maintained the weight they had at age 35. This finding seems at variance with other studies that have associated weight gain with a host of health problems that tend to lower life expectancy.

OK, so we are told that two groups are compared. They are the same, in terms of age. As they get older, the heavier group lives longer than the lighter group, which goes against science. How do we resolve this? My intial reaction was Group A does something that Group B doesn't do, or that the weight is healthy for some reason, but there is not enough information to feel great about anything, so on to the answers!

Which one of the following, if true, most helps to resolve the apparently conflicting findings?


(A) As people age, muscle and bone tissue tends to make up a smaller and smaller proportion of total body weight --OK, who cares? This says that muscle and bone make up less percentage of our weight. So let's say the heavier group has less bone and muscle tone then the lighter group. How does this resolve anything? We would have to assume that having less of these things makes you healthier. We cannot say this. And what is filling the gap in weight? Is it healthy? We have no clue, so this is out.

(B) Individuals who reduce their cholesterol levels by losing weight can thereby also reduce their risk of dying from heart attacks or strokes -- Skinnier is healthier in this case. So it doesn't do anything for our argument.

(C) Smokers, who tend to be leaner than nonsmokers, tend to have shorter life spans than nonsmokers -- So the skinnier people tend to be unhealthier because of smoking. This is perfect! I admit it is not a great LSAT answer, but it truly is the only one standing that has a chance and gives us a reason. We have to assume that some in the group are smokers, but this does help bridge gap better than any other answer

(D) The normal deterioration of the human immune system with age can be slowed down by a reduction in the number of calories consumed -- Similar to (B), this would make skinnier people healthier, so it is out.

(E) Diets that tend to lead to weight gain often contain not only excess fat but also unhealthful concentrations of sugar and sodium -- Same as (B) and (D), although it is far more random and out of place because this talks about diets. We are never told anything about the diets, so this is trying to force an assumption. But that assumption would lead you to conclude that skinnier is healthier, so out.