“Protein hunger” can lead to overconsumption of highly processed foods and obesity, according to a new study. Researchers have studied the link between protein consumption and calorie intake. Researchers have found a link between lower protein intake and higher fat and carbohydrate calorie intake, which may increase the risk of obesity. They concluded that consumers, industry and governments should prioritize reducing consumption of highly processed foods and increasing consumption of whole foods. Obesity is linked to some of the leading causes of preventable premature death, including heart disease, stroke, type 2 diabetes and cancer.
First proposed in 2005, the protein lever hypothesis (PLH) is a theory about the cause of obesity. It states that if the body’s protein needs are not met, the consumption of fats and carbohydrates increases, which dampens signals of satiety and increases food intake. Studies by trusted sources have shown that as the percentage of energy from protein has decreased in American diets, obesity rates have increased. Another study found that hospitalized adults exposed to ultra-processed diets ingested more carbohydrates, fats and total energy than those on unprocessed diets and therefore gained weight. Understanding the health effects of ultra-processed foods and low protein intake could improve obesity prevention strategies. Recently, researchers have analyzed population health data to understand the relationship between protein intake and obesity. They found a link between lower protein intake during the first meal of the day and higher overall food intake throughout the day. The results of the study are published in Obesity.
The Impact of Protein Intake on Overall Diet
Researchers analyzed data from the Australian Bureau of Statistics’ 2011-2012 National Nutrition and Physical Activity Survey. They included data from 9,341 people whose average age was 46.3.
The data included:
caloric intake from protein, carbohydrates, fats, fiber and alcohol.
food consumption time
body mass index (BMI)
The average energy intake was 2072 calories, of which:
18.4% protein
43.5% carbohydrates
30.9% fat
2.2% fiber
4.3% alcohol
By comparing energy intake and timing of consumption, the researchers found that people who ate lower amounts of protein at the first meal of the day had higher calorie intake at subsequent meals. The researchers noted that as protein intake decreased, energy from fats, carbohydrates, sugars and alcohol increased in what is known as “protein dilution”.
They also noted that people who ate less protein at the first meal ate more highly processed foods over the course of the day. This study suggests that in humans, the consumption of meals low in protein at the beginning of the day leads, through the protein lever, to an overconsumption of energy (fats and carbohydrates).
Although people who eat low-protein breakfasts tend to choose higher-protein meals later (at lunch and dinner), they don’t quite make up for their low-protein start to the day, either. so that at the end of the day, the overall daily diet is lower in protein and higher in fat and/or carbohydrate than people who start the day with higher protein meals.
Protein deficiency and overeating
The researchers noted that many factors may explain why humans are predisposed to consuming highly processed foods. These include the following factors:
taste
the cheap price
the commodity
aggressive marketing
general availability
corporate political activity that interferes with public health policy.
They also noted that savory umami-flavored snacks could hijack the body’s protein-seeking responses in what’s known as the “protein lure effect.” They wrote that these products could exacerbate, rather than satisfy, a protein deficiency.
Add protein to breakfast
Protein slows down the rate at which we digest and absorb sugars and carbohydrates from our food, just like fats. If we eat a breakfast full of highly processed or sugary foods, we digest and absorb these foods quickly.
This causes our insulin levels to spike very quickly, causing our cells to remove sugar (glucose) from our blood very quickly, assuming we don’t have diabetes. This then leads to a rapid drop in blood sugar levels, which can make us feel hungry again and stoke that appetite, even if we’re not actually hungry.
If you are hungry then you are more likely to eat, and if you have cravings, lack of sleep, proximity to food, smell of food, there are so many complex variables here about what the ‘let’s choose, even your gut microbiota plays a role in the type of food you choose, so you may be more likely to eat.
How much protein should you eat?
A study from earlier in the year suggested that diets with less animal protein and higher levels of complex carbohydrates are most beneficial for long-term health and lifespan. When asked how the results of the current study suggesting higher levels of protein match up with these earlier findings.
But a previous study noted that fiber can be a healthy substitute for high levels of protein. The theory that low protein “leverages” high fat and carbohydrate intake applies to diets that are high in processed foods that are low in fiber and protein. Under these conditions, we consume too much energy to reach our protein goal. On the other hand, for people whose diet includes a high proportion of whole plant foods, rich in fibre, the latter partly replace proteins by providing the feeling of satiety which makes it possible to stop eating.
Benefits of higher fiber intake include reduced protein intake, which has been linked to increased lifespan, and increased levels of micronutrients and other beneficial compounds like lost antioxidants in industrial food processing. All of these mechanisms likely explain why diets associated with the longest healthy lifespans (e.g., traditional Okinawan diet, Mediterranean blue zone, etc.) are low in protein (not much more than 10% of protein). energy, compared to around 15-18% for typical Western and Australian diets) and rich in plant foods.