## [Effect of a plant-based, low-fat diet versus an animal-based, ketogenic diet on ad libitum energy intake - PubMed](https://pubmed.ncbi.nlm.nih.gov/33479499/) After reading that [[2023-05-07#[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/)|study on UPFs]], I'm on a Kevin Hall kick. Here he locks some folks in a metabolic ward and feeds them either a low fat plant based diet or a ketogenic diet. The subjects eat a lot more on the ketogenic diet. > We found that the low-fat diet led to 689 ± 73 kcal d-1 less energy intake than the low-carbohydrate diet over 2 weeks (P < 0.0001) and 544 ± 68 kcal d-1 less over the final week (P < 0.0001). Therefore, the predictions of the carbohydrate-insulin model were inconsistent with our observations. Both groups lost weight, and the differences in weight loss were not significant. How do we make sense of this given the difference in caloric intake? I seems like the keto group didn't actually lose fat: > Greater weight loss during the first week of the LC [low carb] diet compared to the LF [low fat] diet was likely primarily due to differences in body water, glycogen, protein and gastrointestinal contents. While fat-free mass was relatively preserved with the LF diet, fat-free mass was decreased with the LC diet, which also resulted in a state of of negative nitrogen balance, indicating net loss of body protein despite consumption of more dietary protein than during the LF diet. > Unlike the LF diet that resulted in significant loss of body fat, the LC diet had no significant body fat changes, suggesting that energy intake during the LC diet was approximately equivalent to the total amount of energy that was expended. I guess it's well known that low carb diets (especially keto) lead to a depletion of glycogen stores which contain lots of water. So weight loss on the keto diet was partly due to losing water weight. It also sounds like they lost some muscle mass too, despite eating more protein. Seems bad. [[hall2021.pdf|PDF here.]] Pictures of the meals are included in the [[41591_2020_1209_MOESM1_ESM.pdf|supplementary material]]. Both look pretty healthy to me. Day 5 veggie dinner (vegetarian burrito bowl): ![[Pasted image 20230507215541.png|500]] Day 5 keto dinner (beef stir fry): ![[Pasted image 20230507215649.png|500]] ## [Ad libitum meal energy intake is positively influenced by energy density, eating rate and hyper-palatable food across four dietary patterns | Nature Food](https://www.nature.com/articles/s43016-022-00688-4) I can't access the full text of the article, so the best I can do is [this twitter thread by Kevin Hall](https://twitter.com/KevinH_PhD/status/1620095719469383680?s=20). Some of the findings related to protein intake were surprisingly. Namely that protein intake seemed to *increase* caloric intake both for the current meal and subsequent meal: > Surprisingly, protein content of meals was *positively* related to ad lib meal energy intake (we expected the opposite) during ultra-processed and unprocessed diets but did not significantly affect energy intake of minimally processed low-fat or low-carbohydrate meals. > Previous meal protein intake significantly *increased* subsequent meal energy intake for minimally processed low-carb and low-fat diet patterns (again, we expected the opposite). Only for the diet high in UPFs did protein intake decrease subsequent meal energy intake. The seems like evidence against the protein leverage hypothesis mentioned in [[2023-05-07#[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/)|the UPF study]]. He offers some hypotheses. Maybe previous studies were all in the context of UPFs: > Another possibility is that the effect of high protein content to induce satiety might occur only in the context of a high UPF diet, as we observed. In other words, did previous studies demonstrating protein induced satiety also use meals with a lot of UPFs? See the thread for more. # [From Dearth to Excess: The Rise of Obesity in an Ultra-Processed Food System[v1] | Preprints.org](https://www.preprints.org/manuscript/202303.0107/v1) In this preprint, Kevin Hall charts the rise of UPFs and obesity. I've only skimmed parts of this, but it looks interesting. This is partly a note for me to come back and read it in full.