"A calorie is a calorie is a calorie. If you want to lose weight, you just need to eat less."

"Well, no, your body can react differently to different types of calories. If some calories tend to induce hunger and others don't, then it matters quite a lot which calories you consume."

"Well, yeah, sure, everybody knows that."

Well, no, everybody may "know" it, but when you're not looking, they'll slip "a calorie is a calorie" right back in.

This matters. Either eating certain foods induces more calories to be consumed, in which case the key to dieting is to eat certain foods and not eat others and decades of consensus and advice are irredeemably, irretrievably wrong, or a calorie is a calorie and these sorts of studies are irredeemably, irretrievably wrong (as this is hardly the first one to suggest lower carb or lower GI diets are superior). Some people seem very comfortable just sort of sliding into the "sure, calorie type matters" whenever it is argued, but somehow not being willing to follow the logic that if calorie type matters, then certain further research and conclusions are called for that are sharply at odds with conventional wisdom, which has been very, very much that a calorie is a calorie is a calorie when it comes to weight gain.

Conventional wisdom and decades of dieting advice have been deeply, profoundly, foundationally based on a calorie being a calorie being a calorie, and if that is not true, the conventional wisdom is deeply, profoundly, foundationally if you like, flawed. There's no two ways around this.

(Though I absolutely, positively guarantee that if it does turn out that calorie type matters that this move will be used to slowly but surely rewrite the last 50 years of dietary history such that the conventional wisdom was always right and never said anything about calorie types not mattering. But it won't be true.)