The protein leverage hypothesis states that human beings will prioritize the consumption of protein in food over other dietary components, and will eat until protein needs have been met, regardless of energy content, thus leading to over-consumption of foodstuffs when their protein content is low.
This hypothesis has been put forward as a potential explanation of the obesity epidemic. Empirical tests have provided some evidence to confirm the hypothesis with one study suggesting that this could be a link between ultra-processed foods and the prevalence of obesity in the developed world.
In the 1980s, David Raubenheimer and Stephen Simpson, researchers now at the University of Sydney, began to study appetite and food intake in locusts. By studying responses to artificial diets with differing compositions of protein and carbohydrate, they developed the protein leverage hypothesis. Their experiments showed that those who aren't getting enough protein in their diet will continue to be hungry, even when their overall caloric intake is high. "Protein decoys", such as ultraprocessed savory foods that contain little protein (e,g, barbecue chips), are likely to be attractive and to result in overeating. The hormone FGF21, which is released from the liver, can drive savory-seeking behavior under conditions of low protein intake. However, extremely high protein diets can also have drawbacks. In 2020 Simpson and Raubenheimer published the popular science book Eat Like the Animals: What Nature Teaches Us about the Science of Healthy Eating, which details their experiments. For lifelong health they recommend eating a balanced diet with more fiber and fewer fats and carbohydrates rather than an extremely high protein diet.
In 1995, Australian researcher Susanna Holt developed the concept of satiety value, a measure of how much a given food is likely to satisfy the hunger of someone. High protein foods have been found to have high satiety values, though these are outmatched by potatoes and oats (which have a low glycemic index). Fruits rank similarly to high protein foods (likely due to their high level of dietary fibre).
- Bekelman, Traci A.; Santamaría-Ulloa, Carolina; Dufour, Darna L.; Marín-Arias, Lilliam; Dengo, Ana Laura (2017-05-06). "Using the protein leverage hypothesis to understand socioeconomic variation in obesity". American Journal of Human Biology. 29 (3): e22953. doi:10.1002/ajhb.22953. ISSN 1520-6300. PMID 28121382.
- Simpson, S. J.; Raubenheimer, D. (May 2005). "Obesity: the protein leverage hypothesis". Obesity Reviews. 6 (2): 133–142. doi:10.1111/j.1467-789X.2005.00178.x. ISSN 1467-7881. PMID 15836464.
- Martinez-Cordero, Claudia; Kuzawa, Christopher W.; Sloboda, Deborah M.; Stewart, Joanna; Simpson, Stephen J.; Raubenheimer, David (October 2012). "Testing the Protein Leverage Hypothesis in a free-living human population". Appetite. 59 (2): 312–315. doi:10.1016/j.appet.2012.05.013. ISSN 1095-8304. PMID 22634200.
- "It's Not Just Salt, Sugar, Fat: Study Finds Ultra-Processed Foods Drive Weight Gain". NPR.org. Retrieved 2019-05-17.
- Vernimmen, Tim (1 May 2023). "Like hungry locusts, humans can easily be tricked into overeating". Knowable Magazine | Annual Reviews. doi:10.1146/knowable-050123-1. Retrieved 9 May 2023.
- Raubenheimer, David; Simpson, Stephen J. (17 July 2016). "Nutritional Ecology and Human Health". Annual Review of Nutrition. 36 (1): 603–626. doi:10.1146/annurev-nutr-071715-051118. ISSN 0199-9885. Retrieved 9 May 2023.
- Raubenheimer, David (2020). Eat like the animals : what nature teaches us about the science of healthy eating. Sydney, NSW: HarperCollins Publishers. ISBN 1460758692.
- Skarnulis, Leanna (September 25, 2009). "Satiety: The New Diet Weapon". WebMD. Retrieved 9 May 2023.