By Aly Walansky
Updated March 07, 2016
© Con Poulos

There’s a lot of mixed messages when it comes to high-protein diets. Some will tell you it’s the greatest thing ever, others that it’s a terrible plan – but research suggests protein-rich diets are indeed a great way to feel full and control weight.

A meta-analysis of five different diet and nutrition studies that appeared in the Journal of the Academy of Nutrition and Dietetics revealed that a diet that is high in protein is a great way to feel full and stay full longer, which, in turn, can help maintain or even lose weight.

Diets like Aktins and Paleo have helped people balance their diet successfully. But this research conducted at Perdue University, is the first to provide scientific evidence to back up its efficacy. The research combined the evidence of 33 independent studies. A common factor of all of these studies is that participants were asked to fast prior to eating a protein-rich meal. The subjects were then evaluated based on how long they felt full following the meal. New research required participants to eat a high protein snack prior to a meal, something called a “pre-load”. Those who did this felt more full than those who ate nothing or a low protein snack.

"A good deal of evidence suggests that protein activates satiety [fullness] hormone release and so should be most strongly tied with fullness ratings," nutrition researcher Richard Mattes of Purdue University, said in a journal news release.

But how much protein do we need to feel full? The study fails to indicate other factors that may lead to one eating more or less in a day – such as emotional hunger or mindless eating.

“This research isn't surprising as dietitians have known for a long time that protein is satiating, which is why I always recommend meals and snacks include a source of protein,” says registered dietitian nutritionist Jessica Fishman Levinson, founder of Nutritioulicious. “ While the caveman diet is very popular and this research adds to the theory that more protein is better, we can't be so quick to say that protein should be eaten at the expense of other nutrients, namely carbohydrates. Carbs are still our primary source of energy and an important component of a healthy diet. When it comes to carbohydrates, it's the type that matters - meaning we should be eating fruits, vegetables, and whole grains, not refined carbohydrates that make our blood sugar rise quickly leaving us hungry shortly thereafter,” says Levinson.

As for protein, the research has been showing that we need to space out protein intake more evenly throughout the day, rather than relying on dinner to be our big protein meal. “The researchers studying recommend people get 25-30g of protein at every meal, with 30g being the max our bodies can use at one time,” says Levinson.

So, protein is just a component of a bigger picture. Still, weight control is easier when you are not hungry all the time.