Ultra-Processed Foods Hijack Brain Rewards, Driving Obesity Epidemic

Key Quotes

"when people are losing weight and they're they are decreasing their body size either by you know an exercise intervention a diet intervention a pharmacotherapy or something like that um they tend to at rest their resting metabolism when they're not moving is decreasing now it seems to decrease even more than you'd expect at least transiently while they're in an active weight loss compared to what you'd expect for their decreasing body size larger people burn more calories than smaller people so it goes to you know figure that you would as you become smaller you burn fewer calories but it turns out in the process of becoming smaller during that period when you're actively losing weight it seems like it uh metabolism slows even more than expected this is something called metabolic adaptation"

Kevin Hall explains that during active weight loss, an individual's resting metabolism tends to decrease more than expected based solely on their reduced body size. This phenomenon, termed "metabolic adaptation," suggests the body actively slows down to conserve energy. Hall highlights this as a significant factor in understanding weight management challenges.

"what we observed in the biggest loser was that the people who were most successful at losing weight uh during this kind of crazy competition they were the ones who experienced the most slowing of metabolism so that was kind of weird it was like okay what's going on in there why is it seemed to be completely the the expected correlation was flipped and then there is this idea that the slowing of metabolism well that's got to be a bad thing that's got to predict who's going to regain the most weight after this crazy competition and there tended to be turned out to be no no significant relationship whatsoever um with who regained the most weight it wasn't the folks who had the greatest slowing wasn't the folks who had the least amount of slowing it was more or less random"

Kevin Hall discusses a surprising finding from the "Biggest Loser" study: participants who were most successful at losing weight also experienced the greatest slowing of their metabolism. This contradicted the expectation that a slower metabolism would predict weight regain. Hall points out that the degree of metabolic slowing did not significantly correlate with who regained weight, suggesting other factors are at play.

"the implication was that a calorie is a calorie when it comes to body fat loss but the precision of those measurements was back from the you know the 19th century and um it also didn't necessarily follow that the that it couldn't be that there was a some precise combination of carbohydrates and fats that could cause calorie expenditure to vary and if that happened then you could still not violate any laws of physics but you could have it so that and this is what atkin's claimed right he claimed that if you cut carbs enough in the diet um you're you would have a metabolic advantage he called it which was essentially saying that the body was inefficient at running on fat and would have to burn more calories as a result"

Kevin Hall addresses the concept of "a calorie is a calorie" in relation to body fat loss, referencing historical experiments. He notes that while early findings suggested calorie equivalence, there was a possibility that specific macronutrient combinations could influence calorie expenditure. Hall mentions the claim that significantly reducing carbohydrates could create a "metabolic advantage" by making the body less efficient at running on fat, thus burning more calories.

"the funny thing is that and we're only beginning to understand this you take that same person and you shift them to a different food environment what was effortful before is no longer effortful in other words whatever points that were regulating our body weight and our appetite and our energy expenditure those those controls that are helping us regulate body um weight turns out to be incredibly influenced by the the food environment that we find ourselves in"

Kevin Hall emphasizes the profound impact of the food environment on body weight regulation. He explains that shifting an individual to a different food environment can make previously effortful dietary changes feel effortless. Hall suggests that the body's regulatory controls for appetite, energy expenditure, and body weight are highly susceptible to environmental influences, a concept that is still being actively researched.

"the 800 pound gorilla in the room is ultra processed food so when we're talking about food environments i mean that is the kind of lurking giant that's driving all of these deleterious health outcomes"

Kevin Hall identifies ultra-processed food as the primary driver of negative health outcomes, referring to it as the "800-pound gorilla." He asserts that this category of food is the central issue within our current food environments, contributing significantly to widespread health problems. Hall's statement underscores the critical role of ultra-processed foods in the obesity epidemic and related chronic diseases.

"the other big externality has been healthcare costs right i mean the fact that um we are experiencing this this dramatic increase in diet related chronic disease that is you know essentially bankrupting medicare medicaid and and the health sector and to think that this entire process of you know solving malthus's which is essentially we've solved malthus's problem right and we have to do something to kind of change this not just for the health crisis but the fact that we're going to have 10 billion people on the planet and you know not too far distant future that solves malthus's problem because the population is no longer expected to increase what do we have to do to the food system to both ensure that we have equitable distribution of calories and that those calories are actually healthy for us and the planet that's the grand challenge of agriculture and nutrition and food science for the next you know several decades"

Kevin Hall connects the rise in diet-related chronic diseases to escalating healthcare costs, describing it as a crisis that is bankrupting healthcare systems. He frames the challenge of feeding a growing global population with healthy and equitably distributed calories as the central task for agriculture, nutrition, and food science in the coming decades. Hall suggests that addressing these systemic issues is crucial for both public health and planetary sustainability.