Obesity.

There’s too much money to be made in “curing” obesity. And money is the main motivator of invention.

Yes, there are already “cures” for obesity: lifestyle changes and surgeries. The problem with those is that, while they save money for insurance companies in the long run, they lose money for the food industry. Plus, they aren’t really working, are they? We’ve known for generations what makes people obese. We’ve known how to fix it via lifestyle changes. And yet the problem just keeps getting worse.

The food industry is very powerful. But they have a problem too… there’s a limit as to how much of their product people can use.

But imagine if there was no limit. Imagine if you could eat all you wanted (and spend all of your money on food), but maintain a healthy weight. There’s two ways to do this:

Create safe, calorie-free foods that are indistinguishable from the calorie-filled regular kind. Not just “diet Coke” that tastes horrible and is even worse for you than the regular kind, but actual safe, calorie-free foods of all kinds.
Create some sort of medicine that would prevent calories from being absorbed by your body. Eat 5,000 calories of day (and pay for them!) every day, and your body will only absorb the number of calories you want it to. The rest just passes right through you.
I suspect there will be a combination of both of those in the next 50 years. There’s too much money to be made feeding people things when they aren’t really hungry. And there’s too much money to be saved by curing obesity.