It's hard to believe now, but back in 1968, nerdy boys apparently were more anxious about being too skinny to be attractive to women, than the other way around, at least if ads like these are to be believed.
I can't find them at the moment, but even funnier was that there were similar ads for women, who I guess were too self-conscious about lacking curves. Funny how times have changed, kind of.
That being said, I won't dwell on this particular ad for too long for two reasons:
1) Products like this are probably more popular than ever, though I'm sure we don't really need them.
2) Those two women are actually pretty damn good looking. If I had to eat gallons of that weight-gain powder dry to bed both those gals at the same time, I'd be so dehydrated, super fat, constipated, and oh-so-happy.
Appeared in Amazing Spider Man #66 - November 1968.