A recent year-long study of nearly 10,000 Australians confirms that highly processed foods are the leading contributor of obesity in the Western world.
As we all know, most processed foods are hyper-palatable — with crave-worthy combinations of sugar, salt, and fat — causing people to overeat.
But the researchers found that it’s something processed food doesn’t have that makes it so problematic: protein.
This study provides evidence for the Protein Leverage Hypothesis, which states that people overeat fats and carbs due to the body’s powerful appetite for protein, which the body prioritizes over everything else.
Because our modern diet consists of so many highly processed and refined foods — which are typically low in protein — people consume more energy-dense foods until their protein needs are satisfied.
“It’s increasingly clear that our bodies eat to satisfy a protein target,” according to Professor David Raubenheimer, Professor of Nutritional Ecology at the University of Sydney. “But the problem is that the food in Western diets has increasingly less protein. So, you have to consume more of it to reach your protein target, which effectively elevates your daily energy intake.”
This means that as the protein in our diet is diluted by fats and carbs —common in processed foods — we will eat more calories to get the protein our bodies desire.
This phenomenon is especially apparent for the meal of the day.
The study found that people who consumed lower amounts of protein in their first meal of the day went on to eat more at subsequent meals, whereas those who ate a high amount of protein at their first meal actually declined their food intake over the rest of the day.
This was true even though the first meal was the smallest for both groups, with the least amount of energy and food consumed, whereas the last meal was the largest.
Eating more protein early in the day helps satisfy your overall protein requirements, causing you to eat less later. This is an important insight for people trying to lose weight more easily.
People who eat a low-protein first meal are found to eat more energy-dense foods high in saturated fat, sugar, salt, or alcohol later in the day, and less ‘healthy’ foods such as vegetables, fruit, legumes, and meat.
While many factors contribute to weight gain — including food, exercise, sleep, and stress — the researchers in charge of this study argue that the body’s strong demand for protein — which is lacking in highly processed food — is the primary driver of energy overconsumption and obesity.
The implications are clear for us.
Avoid highly processed and refined foods.
Prioritize protein over the other macronutrients, especially for your first meal of the day.
If you get at least 30 grams of protein at your first meal, the chances of overeating later in the day are much lower.
This is a powerful ‘hack’ — backed by science — to maintain a healthy weight without really trying.