What leads me to this conclusion is the the next fad diet will be "calorie restriction" and apples are apparently the best way to stay on track with the diet.
A recent New York Times feature on calorie restriction includes lots of hyper-active, healthy middle aged people who are part of the Calerie study being run by the National Institutes of Health, munching happily on apples.
Subjects are recruited to cut their daily calorie intake by 25% in order to study its effects on aging. They are also given intensive tests at regular intervals to check markers of aging, like inflammation.
They're still recruiting, but no fatties. Your body-mass index going in must be in the normal range of 22-28. (Mine's 28.2. What's yours?)
There is evidence that calorie-restriction works in mice. Doctors want to know whether it really works in ordinary people, how well it works, and how hard it is to stick with.
That's where the apples come in.
Apples have a lot of fiber, a good deal of taste (try the braeburns or fujis, the red delicious are not what they used to be) and they make you feel full even if you're not. They're easy to carry, they take no preparation, they're as American as (well) apple pie.
Throughout freelancer Jon Gertner's Times' feature he has study subjects munching away on apples. And this study may mean longer life. (Call it the Granny Smith diet -- my mom eats like a bird, which is to say not much.)
All the ingredients are there for a massive food fad, on the order of the Atkins' no-carb frenzy of several years ago. I don't know if the study's authors know this yet, but if you want to make some serious coin you might want to get some nutrition education and learn how to prepare calorie-restriction diets that taste good.
Or just eat more apples and get into your fat friends' wills.