A flat-chested girl with a bit of a gut wrestles with her belly fat while shouting, and eventually pushes it up into her chest. She grows from nothing to decent C cup breasts! Not bad!
The ad appears to be for a slenderizing green tea blend.
Kelp-A-Malt
There are a ton of these old weight-gain ads for women from the 20s and 30s. Typically they appeared in magazines for young women and in fitness publications. What’s interesting is that a swell in breast size was usually incidental to overall filling-out. So the skinny girl would fill out in the shoulders and hips as well as experiencing increased breast development.
The ad at right is for a product called “Kelp-A-Malt”, though “Ironized Yeast” more commonly used this sort of tableau. In this one, the target customer isn’t meant to merely fear that her lack of curves and small breasts might cost her success with men – which is the most common approach – but also that inferior, flatter-chested women will learn the secret of growing larger breasts and will leave her behind. It’s particularly nasty – start buying Kelp-A-Malt today or your friends will all have bigger boobs than you!
I got this one from Modern Mechanix. It’s from the November, 1934 issue of Physical Culture.
Bubble gum breast size change
I’ve always loved this video because of the random potential outcomes. At the end she inhales the air back in along with the bubble gum, and her breasts grow to the greatest size we’d seen them. But what if she coughed, instead? What if she exhaled all the air and inflated the bubble gum, but then coughed and spit it out? She’d have wound up totally flat-chested instead of super-stacked!
Now that’s a good story hook!
She’s Drinking Milk!
This is an oldie-but-goodie from Japanese TV. A girl consumes a carton of milk and her breasts grow to substantial size beneath her shirt. (Milk allegedly can make breasts grow significantly, but not so fast as in this ad.)