July 5, 2014
New Study Explains Why High-Protein Diets Can Help People Lose Weight
redOrbit Staff & Wire Reports - Your Universe Online
Eating foods that are high in protein can be a more effective way to lose weight than the more traditional calorie-counting method, according to research presented this week at the Annual Meeting of the Society for Experimental Biology in Manchester, England.
While the nutritional values of food are typically given in standard energy units such as kilojoules or kilocalories, University of Sydney nutritional ecologist Professor David Raubenheimer and his colleagues argue that this method is too simplistic, and that more emphasis needs to be placed on the role of macronutrients.
Those macronutrients (carbohydrates, fats and proteins) typically interact in order to regulate appetite and energy intake, the researchers explained Thursday in a statement. In apes and monkeys, the study authors found that the correct balance of nutrients was more important than the overall energy intake of the creatures.
“Foods are complex mixtures of nutrients and these do not act independently but interact with one another. The appetite systems for different nutrients compete in their influence on feeding,” said Raubenheimer.
Eating nutritionally-balanced foods prevent competition in those appetite systems, meaning that when one nutrient requirement is fulfilled, the others are as well. However, many types of foods do not have the correct balance, possessing a protein-to-carbohydrate ratio that is too high or too low. As a result, for an animal to obtain the right amount of muscle-building protein, they would have to consume too many or too few fats or carbohydrates.
As part of their research, Raubenheimer and his fellow investigators monitored baboons living near human settlements. They found that, despite eating different food combinations each day, the creatures maintained a consistent balance in which one-fifth of their overall energy needs came from protein. However, their total energy intake varied greatly – in fact, the energy intake range could be five times greater on occasion.
The professor said that the findings suggest that the baboon places a higher value on maintaining the right balance of micronutrients over the total energy intake. Previous research had demonstrated that other primates also tend to forage to maintain a balanced diet, but noted that they prioritized protein over fat or carbohydrates when seasonal unavailability of some food types made it impossible to consume regular levels of all three.
However, gorillas have the opposite approach, tending to consume significantly higher amounts of protein in order to maintain their target carbohydrate consumption levels, Raubenheimer said. He added that this demonstrates “that there is diversity even among closely related primates. It also demonstrates that an energy-only approach is not adequate to understand primate foraging or for making conservation decisions.”
Humans typically behave like spider monkeys and orangutans, tending to prioritize protein over the other types of nutrients. As a result, if people eat a low-protein diet, they will over-eat fats and carbohydrates in order to ensure that they reach their protein consumption targets. The study authors believe that this could help explain the rapid rise in obesity levels in the Western World, despite the decrease of protein consumption, over the past six decades.
“We can use this information to help manage and prevent obesity, through ensuring that the diets we eat have a sufficient level of protein to satisfy our appetite,” said Raubenheimer. While these findings could explain why high-protein diets can help people lose weight, the professor cautions that people need to get the right balance of fats and carbohydrates as well – otherwise, those “imbalanced” could result in “other health problems.”
“A simple rule for healthy eating is to avoid processed foods – the closer to real foods the better,” he added. “Whilst it is clear that humans are generalist feeders, no human population has until recently encountered ‘ultra-processed foods’ – made from industrially extracted sugars, starches and salt. Our bodies and appetites are not adapted to biscuits, cakes, pizzas & sugary drinks and we eat too much of them at our peril.”