Nutrition
How Protein Makes You Slim
The protein leverage effect shows that higher protein intake leads to lower overall calorie intake – a key factor in weight loss.
Nutrition
The protein leverage effect shows that higher protein intake leads to lower overall calorie intake – a key factor in weight loss.
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Last week we reported on Protein-sparing modified fast, or PSMF for short. That is, the discovery that fasting with protein per unit time promises more fat loss than conventional fasting alone.
The background is that 30% of the supplied protein calories simply dissipate as heat ("thermic effect"). The remaining calories – at least in the physiological context of 1–2 g protein per kg body weight – go toward maintaining structure, and thus do not contribute to fat storage.
The "secret knowledge" is: Mammals seem to regulate their total energy intake based on the protein calories they consume. Researchers have observed for a long time: The fewer protein calories a species consumes, the more calories from fat and carbohydrates – and thus total calories – the animals consume.
So we can remember:
The more "diluted" the protein content of food, the more total calories animals consume.
Why is protein so important? Because it provides essential building blocks in the form of amino acids. Carbohydrates and almost all dietary fats are not essential – the body can easily do without them.
Apparently, protein is so important for many animals that their total food intake is adjusted based on it. Researchers call this "protein leverage."
In the journal of the Royal Society, which serves as the national academy of sciences in the United Kingdom, a remarkable paper on protein leverage was recently published.¹
Scientists there describe how protein across species regulates energy intake and thus has significant influence on obesity and metabolic disorders in modern societies. The authors write:
"We present evidence for protein leverage from a variety of sources (mechanistic, experimental, and observational) and show that this mechanism is compatible with many other findings and theories of obesity research."
Protein leverage takes effect especially in the range of 10 to 30% of protein calories. For comparison: Studies show that men on average consume 85 g of protein. The average energy intake for men is 2,400 calories – which constitutes a protein share of 14%.
Similar patterns can be seen in Switzerland. Based on comparable data, we see here too that we are directly in the range of protein leverage – to our disadvantage.
In the mentioned study, researchers show based on high-quality human studies that total energy intake in humans decreases by around 500 calories when the protein proportion of food triples from 10% to 30%.
In concrete terms: Doubling protein intake here – that is, from 14% to 30% – would result in a decrease in total calorie intake of 300 calories. For men, that is a whopping 12.5% of total calories. Astounding numbers!
Right. Good point. The protein has to come from somewhere. For example, from animal sources (milk, eggs, meat, fish, etc.). Generally: The more high-quality – i.e., nutrient-rich – a food is, the more greenhouse gases are emitted in its production on average.
One could say: A healthy, nutrient-rich lifestyle tends to make the environment sicker. The authors also make this same argument in their paper. But they show once more why we need to think outside the box…
The scientists explain: If protein leverage takes effect due to low protein intake, society runs the risk of compensating for the natural calorie over-compensation with calories from highly processed, industrially manufactured foods.
Aha! And that is truly poisonous for the environment. And anyone who thinks about it will understand that we in Switzerland also get a large share of our calories from highly processed products. Key point: 14% protein.
These dynamics demonstrate very well why linear thinking in dealing with complex problems usually doesn't take us far.
1 Raubenheimer & Simpson (2023): "Protein appetite as an integrator in the obesity system: the protein leverage hypothesis"
2 Saner et al. (2023): "Evidence for protein leverage in a general population sample of children and adolescents"
3 Zhang et al. (2023): "Evidence for the protein leverage hypothesis in preschool children prone to obesity"
4 Honfo et al. (2023): "Evidence for protein leverage on total energy intake, but not body mass index, in a large cohort of older adults"
