Kevin Hall

Thanks for having me.

Right.

So we were actually trying to isolate the effects of the foods per se, right?

So there's all these other aspects of the food environment that Julie alluded to, the kind of the social environment that we find ourselves in, the advertising, the cues in our environment, the expense, the

the time commitments that it takes to require to prepare healthy foods or unhealthy foods, as the case may be.

We decided to try to remove all of that from these experiments.

And we brought people in to the NIH Clinical Center where I used to work.

And we basically removed people from their normal food environments, created this very artificial food environment for them just to kind of isolate that food environment.

And

Basically exposed them to diets that had plenty of calories, more than double the number of calories that they would require to maintain their weight.

Tried to match them for as many of these different sort of nutrients of concern that we often hear about, the salt, sugar, fat, carbs, glycemic load of the diets matched again for the total calories that we presented to people with.

And in one instance, we presented them with a diet that contained none of these so-called ultra-processed foods.

And in another occasion, we presented them with a diet that contained 80% of calories from ultra-processed foods and just gave people very simple instructions.

In this new food environment, you know, we're interested in seeing how it affects your biology.

We're going to be poking and prodding you, putting you in respiratory chambers, measuring your body composition, all sorts of things.

What they didn't know was that we were going to be measuring all their leftovers.

And we would basically be trying to figure out how much of the food presented to them did they actually eat and which foods did they eat, which ones did they leave on their plate.

And really simple instructions, eat as much or as little as you like, don't be trying to change your weight at all.

And what we ended up finding was that despite matching for the presented calories and all these different nutrients,

When people are exposed to this ultra-processed food environment, they tend to overeat calories.