## [Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake - PubMed](https://pubmed.ncbi.nlm.nih.gov/31105044/) I'm taking another look at the study on ultra processed foods (UPFs) that I [[2023-05-06#[@sguyenet: A simple general theory to explain the obesity epidemic](https://twitter.com/sguyenet/status/1654316831589699584)|posted yesterday]]. Some assorted notes below. Although they attempted to match these diets as much as possible, they were not able to match across all dimensions. The UPF diet contained more added sugar, less fiber, more saturated fat, and more omega-6s vs omega-3s. > While we attempted to match several nutritional parameters between the diets, the ultra-processed versus unprocessed meals differed substantially in the proportion of added to total sugar (~54% vs 1%, respectively), insoluble to total fiber (~16% versus 77%, respectively), saturated to total fat (~34% vs 19%), and the ratio of omega-6 to omega-3 fatty acids (~11:1 vs. 5:1). So UPFs cause increased caloric intake and weight gain, and also tend to have more saturated fat, omega-6s, etc. Could these components be part of this causal link? Or are they just associations? PUFA truthers will often point to the association between increased omega-6 intake and obesity as evidence that omega-6s are harmful, but it's really unclear to me if omega-6s are causal or if they are just associated with the rise of ubiquitous UPFs. The difference in intake is absolutely eye popping. Folks on the UPF diet ate way more every single day: ![[Pasted image 20230507160936.png|700]] The supplementary material contains the entire menu. The UPF diet basically looks like the average American meal. Here is the day 3 processed dinner (meatball sub, keebler crackers, and crystal light): ![[Pasted image 20230507161313.png|500]] Here is the day 3 unprocessed dinner (beef, couscous, green beans, salad, black bean hummus, baby carrots): ![[Pasted image 20230507161233.png|500]] The unprocessed meals were more expensive, and took longer to prepare. I might steal some meal ideas from here: [[NIHMS1528772-supplement-1.pdf|PDF]]. This is absolutely fascinating. The fact that protein intake between both arms of the study was consistent is evidence that the additional caloric intake in the UPF condition might be the body trying to get adequate protein (the *protein leverage hypothesis*). > The increased energy intake during the ultra-processed diet resulted from consuming greater quantities of carbohydrate (280±54 kcal/d; p<0.0001) and fat (230±53 kcal/d; p=0.0004), but not protein (−2±12 kcal/d; p=0.85) ([Figure 2B](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946062/figure/F2/)). The remarkable stability of absolute protein intake between the diets, along with the slight reduction in overall protein provided in the ultra-processed versus the unprocessed diet (14% versus 15.6% of calories, respectively) ([Table 1](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946062/table/T1/)), suggests that the protein leverage hypothesis could partially explain the increase in energy intake with the ultra-processed diet in an attempt to maintain a constant protein intake ([Martinez Steele et al., 2018](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946062/#R27); [Simpson and Raubenheimer, 2005](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946062/#R56)). People liked the unprocessed and ultra processed foods equally: > Participants did not report significant differences in the pleasantness (4.8±3.1; p=0.13) or familiarity (2.7±4.6; p=0.57) of the meals between the ultra-processed and unprocessed diets as measured using 100-point visual analogue scales ([Figure 2D](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946062/figure/F2/)). There's more in the article. I'll continue when I have time.