Is Protein Thermogenic?
By Chad Kerksick, PhD
Increase Calorie Burning Efficiency and Control
Appetite by Boosting Your Protein Intake
The balance between the amount of calories you are eating and the number of calories you are burning is a key factor which dictates your ability to lose weight, maintain optimum weight, and improve your body composition. While many people take this axiom to mean "a calorie is a calorie," there's really much more to the story. I once heard Jose Antonio, CEO of the International Society of Sports Nutrition liken this to saying that 1,000 calories from McDonald's french fries and 1,000 calories of fresh fruit would have the same impact on your body. While some may consider this to be an extreme, unfair example, the point is made.
Much is made about dietary protein for building muscle, but recent studies have continued to provide more and more support that an increased dietary intake can help increase calorie burning and promote feelings of fullness (which should reduce the amount of food you consume) [1-4]. Based on its capacity for increasing calorie burning to a greater extent, regular protein intake may have more importance than carbohydrates or fat when considering calorie burning and your ability to control your bodyfat. In this respect, what type or form of protein is being discussed with regard to this research? Are we talking primarily about eggs, chicken, milk, beef, tofu, soy milk, or some form of supplementation? Currently, studies haven't clearly indicated that one form or type of protein is more advantageous, but only that consuming it in increased and regular amounts could provide the most benefit. So if you like eggs, start cooking. If you like chicken, that will work. If you often get your protein in the form of a meal replacement or whey protein supplement, that can be effective as well.
For example, a 2004 review  concluded that convincing evidence exists to demonstrate that a higher protein intake increases calorie burning and controls appetite better than diets of lower protein content, resulting in a reduced energy intake, increased weight loss and fat loss. Similarly, Leidy and colleagues had obese men consume meals of identical calories amounts but were either 14% or 25% protein, respectively, in three or six eating occasions each day. When higher protein was consumed (25% protein) greater levels of satiety (feeling full) were reported, regardless of how many times a person ate each day . Another study compared identical sized meals, but had varying amounts of carbohydrates and protein and those meals which had higher protein increased calorie burning to a significantly greater extent when compared to a meal with more carbohydrates . More recently, investigators utilized a group of guys who regularly lift weights for exercise to determine whether protein supplementation before a weight lifting workout favorably changed post exercise calorie burning rates . Quite surprisingly, the authors found that 24 hours after the exercise bout, r esting energy expenditure in response to protein supplementation was significantly greater when compared to a carbohydrate containing meal. While the previously mentioned studies are exciting, they only measured changes after one meal on one day and we all know that changes in your body, no matter how exciting in the short term, take several weeks to result in changes to your body. For these reasons, investigators had people consume higher carbohydrate and higher protein diets for four weeks  and then switched to the other diet for another 28 days. Changes in calorie burning were a key part of this study and researchers determined that the calorie burning rate was 100% greater when a higher protein meal was ingested when compared to a higher carbohydrate meal. In addition, nitrogen balance was significantly greater when ingesting the high protein diet meaning the body was in a more favorable state to build muscle or at the very least help prevent muscle loss which often occurs when calories are restricted during dieting. Given this information, one can assume that these increases in energy expenditure, if extrapolated over several weeks, would lead to positive changes in body weight and composition, particularly if caloric restriction is employed.
So as these studies get progressively longer and longer the same message keeps appearing which is protein can and should be an integral part of any diet program. This message is also clear in a few studies that sought to illustrate the impact of increased protein on weight loss, body composition, health markers, satiety and energy levels [11-13]. For example, increasing dietary protein from 15% of the total calories you consume each day up to 30% led to a decrease in desired calorie intake . In one of the most convincing studies, researchers at the University of Illinois examined the efficacy of two weight loss diets with modified carbohydrate and protein ratios to change body composition in women both with and without regular exercise [12, 13]. One group of women were assigned to a 1,600 calories per day diet which provided a greater proportion of calories from carbohydrate (68 g protein/day or 17% protein) or a group that ingested more protein (125 g protein/day or 31% protein). When more protein was a part of the person's diet, significantly greater losses of fat were found when compared to the higher carbohydrate diet and these results were found when women exercised and when they didn't. Of course, those women who combined the higher protein diet with the exercise program easily lost the greater amounts of fat; the take home message is simple. A greater protein intake can be a valuable tool to help increase calorie burning, sustain your appetite and now help you to lose more fat whether you exercise or not.
Finally, a number of studies have compared the impact of diets containing different ratios of fats, carbohydrates and proteins [14-16]. The most important of these studies compared people with an elevated risk for developing diabetes and heart disease and found that a higher protein diet resulted in greater weight loss and fat loss and overall doing a better job of improving the person's health profile.
In closing, increased dietary protein is an effective approach to help a person burn more calories throughout the day, feel more full and satisfied from their diet and lose more fat. I don't care what kind of protein you use to get these results and until studies clearly show that certain proteins are better, a number of options exist. Certainly, while eggs, beef, cottage, chicken, etc. all have favorable additional nutrients, the most practical consideration on a day-to-day basis may be core ProSource products like NytroWhey Ultra Elite or Vectron. The convenience and tasty options that exist make these types of products and others like them from ProSource key factors to consider. A number of products could be helpful, but the reputation behind NytroWhey Elite and Vectron make them viable contenders. Good luck with you dieting.