Lorna PapeUltra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food IntakeKevin D. Hall, Alexis Ayuketah, Robert Brychta, Peter J Walter, Shanna Yang, Megan Zhou15 May 2019https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30248-7
Increased availability and consumption of ultra-processed foods (‘UPF’) have been associated with rising obesity prevalence, but scientists have not yet demonstrated that UPF causes obesity or adverse health outcomes. Researchers at the NIH investigated whether people ate more calories when exposed to a diet composed of UPF compared with a diet composed of unprocessed foods.
1 How to Bake, Eat & Share Bread according to the 6 pillars of Lifestyle Medicine Principles1. Nutrition & Healthy Eating Principles -, 5. Understanding & avoiding refined flour & UPFAmaranthImpact on Weight Managementhttps://thesourdoughschool.com/the-classic-10-minute-einkorn-sourdough-tin-loaf/https://thesourdoughschool.com/the-classic-10-minute-einkorn-sourdough-tin-loaf/
Researchers found that although the meals were matched for nutritional content across the UPF and unprocessed diet, participants ate more calories, and gained weight whilst eating the UPF diet, but lost weight when eating the diet composed of unprocessed foods. Other interesting points from the study were that the meal eating rate was significantly greater in with the UPF diet, and there was also a decrease in the hunger hormone ghrelin, and an increase in the appetite suppressing hormone PYY when eating the unprocessed diet.
This was a small study, and participants were assisted by having food prepared for them, which would undoubtedly have helped them to maintain the unprocessed diet. However, it also demonstrates the importance of limiting UPF in the diet, and these were clearly shown to cause weight gain. The information on the hormonal changes from the unprocessed diet is also interesting, and is potentially another reason why eating such a diet is also likely to be helpful for weight management.
The references to the decreased hunger hormones / observation that volunteers eating the UPF diet in the previous study had a much higher meal eating rate, also made me think of this study, which I also found interesting:
The acute impact of the intake of four types of bread on satiety and blood concentrations of glucose, insulin, free fatty acids, triglyceride and acylated ghrelin- A randomized controlled cross-over trial
Since median ghrelin AUC was significantly lower and satiety levels were higher when eating Einkorn sourdough, it would seem that replacing an UPF commercial bread with an unprocessed Einkorn sourdough loaf could be a good way to help avoid unnecessary calorie intake and weight gain.