Everyone knows you're supposed to tilt your glass when you pour a beer, so there's not too much foam at the top. But being TOO careful about it can actually make you more bloated. And here comes the science . . .
Having no foam in your glass means you can drink it right away, and you get more beer with one pour. But it also means your beer still has all of the carbon dioxide in it.
When those bubbles pop, the gas expands. Which can either happen in your glass, or in your stomach. And the total volume of the gas in a beer is about two-and-a-half times the volume of the actual liquid.
In other words, you'll feel a lot less bloated if you let some of the bubbles pop BEFORE you drink it. And don't worry. It'll still have plenty of bubbles, so it won't taste flat.
You should still pour down the side of the glass, just don't be too careful about it. With a pint glass, aim for about two inches of foam.
It's especially important if you're also EATING, because when the food hits your stomach, it reacts with the beer and releases even more CO2. So then you end up even more bloated.
Having foam in your glass also means you'll get more of the sweetness from the malt, and bitterness of the hops. So it should taste better too.