Humans, like so many other species, control protein intake more strictly than any other dietary component, so if protein intake is reduced, food intake increases to make up for it. According to the hypothesis, the body consumes extra calories while searching for protein to satiate its natural protein drive because processed foods high in fat and carbohydrates dilute the amount of protein in modern diets.
The current research, which is a result of the Royal Society Discussion Meeting held in London in October of last year, demonstrates how observational, experimental, and mechanistic research is increasingly in favor of protein leverage as a significant mechanism causing obesity.
The protein leverage effect interacts with environments of industrially processed foods and with changes in protein requirements across the life course to increase the risk of obesity, as revealed by the overview of published studies that span mechanisms of protein appetite.
For instance, the need for protein may change during certain life stages (such as the transition to menopause), and these changes may have an impact when combined with changes in activity level or energy expenditure (e.g., athletes who are retiring or young people who are adopting more sedentary lifestyles).
Since data indicates that children and adolescents exhibit protein leverage, the authors discuss the potential impact of preconception or early life exposure to a high-protein diet (for example, through some infant formula feeds) in possibly setting up enhanced protein requirements and vulnerability to lower protein, processed diets in later years.
With the World Health Organization declaring obesity to be the greatest health threat facing humanity, the authors argue that integrative methods that investigate how various contributors interact in obesity should be prioritised over competing explanations. This will also aid researchers and policymakers in comprehending how to advance the field and which causes are most relevant to combating the rising obesity epidemic.
“It is only through situating specific nutrients and biological factors within their broader context that we can hope to identify sustainable intervention points for slowing and reversing the incidence of obesity and associated complications,” the authors concluded.
Raubenheimer, D. & Simpson, S. J., (2023) Protein appetite as an integrator in the obesity system: the protein leverage hypothesis. Philosophical Transactions of the Royal Society B Biological Sciences. doi.org/10.1098/rstb.2022.0212.