The word protein comes from the Greek and means "of prime importance." It's an accurate description. Without dietary protein, your body starts breaking down precious muscle tissue, literally "eating" itself. Among its many responsibilities, protein helps to make enzymes, hormones, antibodies, and about a zillion other things that your body requires to function optimally. I've long been a fan of higher-protein diets for fat loss. Protein from dietary sources has far less of an effect on insulin than carbs, is more satisfying, and requires more energy to break down and assimilate. That's why many weight-loss and nutritional experts refer to protein as a magic bullet for fat loss.
Because your body demands protein, the appetite-control mechanisms that send messages from your gut to your brain work beautifully with protein, much better than they do with carbs. Simply put, eating a protein-rich meal keeps you fuller longer.
You've experienced protein's satiating effects before. Recall a time when you ate a big bowl of pasta. A few hours later, you were probably hungry again-and most likely craving more carbohydrates! Now, think about a time you had a lean chicken breast or maybe a sirloin along with some green veggies (and maybe half a sweet potato). You probably didn't even think about eating the rest of the evening. And though you didn't realize it at the time, you probably ate less during that meal.
Ever wonder why you don't overeat eggs, but have trouble putting the brakes on glazed donuts? A study featured in The American Journal of Clinical Nutrition found that a high-protein breakfast trumps hunger far better than a higher-carbohydrate meal. That's because in addition to suppressing your hunger hormone ghrelin, a higher-protein breakfast increases levels of cholecystokinin (CCK), which tells your brain to stop eating.
Protein at breakfast, in fact, can curb hunger and cravings throughout your day. One study in The American Journal of Clinical Nutrition found that a high-protein breakfast reduced evening snacking and otherwise curbed hunger in overweight and obese teenage girls.
Sustained Fat Loss
Protein has less of an effect on insulin than carbs do, is more satisfying, and requires more calories) to break down. A greater ratio of protein to carbohydrates at mealtimes stabilizes blood sugar and reduces insulin response. And research by Donald Layman, PhD, and other experts suggests that leucine-an amino acid found in protein-specifically helps you maintain muscle mass while losing body fat during weight loss.
In a study that was published in The American Journal of Nutrition, Layman compared a high-protein, low-fat diet with a standard low-fat diet. No contest: the high-protein diet helped retain muscle mass and dissolved fat far better than the low-fat diet.
But weight loss means absolutely nothing if you can't keep that weight off. Knowing this, Layman published a follow-up study in that same journal looking at how people responded to a high-protein diet over 12 months. You guessed it: the high-protein group felt fuller, more satisfied, and had more energy than the low-fat group. More people on the high-protein diet lost weight and kept it off. Also worth mentioning: the high-protein group had improved triglyceride and triglyceride/ cholesterol ratios compared with the low-fat group, both of which are risk factors for heart disease.
Choosing the Best Sources of Protein
I recommend that every meal and every snack contain adequate protein. But all proteins-and all protein powders-are not created equal. Vegetarians and vegans take note: plant-based proteins overall have an inferior amino acid profile compared with animal proteins. That's not necessarily a bad thing; it just means that you'll want to include plenty of higher-protein plant foods, such as quinoa and legumes, in your diet.
Meat eaters, you're not off the hook. You can easily screw up a high-protein diet by eating only deli meats and hot dogs. Yes, they're high in protein, but they're also filled with health-robbing nitrates, sodium, and antibiotics. Skip the processed meats and consume clean protein sources, such as free-range chicken and eggs, wild-caught fish, and grass-fed lamb and beef.
One more thing, meat eaters: When I say higher-protein diet, I don't mean all-protein diet. I certainly don't recommend noshing on only grilled chicken breasts all day. In addition to proteins, incorporate plenty of alkalinizing veggies, low-glycemic fruits, healthy carbs such as quinoa and sweet potatoes, and nuts and seeds.
The Proof Is in the Powder
Protein powders are a terrific way to get high-quality protein into your diet. But which ones should you use?
In a recent USDA study, researchers randomly assigned 90 overweight adults to three groups, all of whom supplemented their diets with a drink. One group drank whey protein, one drank soy protein, and one drank a carb-laden mixture.
At the end of the 23-week study, those drinking the carbohydrate shake had actually gained about 2 pounds, most of it fat. Those drinking the soy protein shake stayed the same. (However, other studies have indicated that soy protein powder alters metabolism in a way that helps with weight loss.) The best
results came with those drinking the whey protein drink. They actually lost a little bit of weight and body fat (about 2 pounds worth). And while both other groups saw essentially no change in their waist size, the whey protein group lost about an inch around their middles.
Interestingly, the people in the whey protein group also had significantly lower blood levels of an appetite-stimulating hormone called ghrelin than those in the other groups. "(Ghrelin) is a hormone that helps regulate food intake," says David J. Baer, PhD, research physiologist and lead author of the study. "So the higher the concentration (of ghrelin), the more hungry someone feels. The lower the concentration, the fuller someone feels."
Protein powders are fantastic for morning smoothies, pre- or post-workout fuel, or any time you need to take the edge off appetite. In addition to soy and whey, you'll find pea protein, which has become all the rage lately. It's often blended with other vegan-friendly proteins such as brown rice protein. Pea protein has an impressive amino acid profile and provides good amounts of leucine, which, as mentioned earlier, Layman considers the "magic ingredient" amino acid for fat loss. Some people complain that pea protein has a gritty taste, though others are fine with it. Especially if you're vegan or sensitive to dairy, it's a great protein-powder choice.
Take It Off Boost your weight-loss efforts with the help of natural supplements—here are three of the hottest ones.
Helps with Weight Loss by …
Green coffee bean
Slowing the absorption of carbohydrates, sugar, and possibly fats in the digestive system.
More efficient metabolism and enhanced energy; reduced appetite.
Helping to burn away fat that lodges around the abdominal zone.
Increased metabolism and fat loss; reduced appetite.
Helping to block the process of fat production; also helps raise serotonin levels.
Weight loss, appetite control, reduction of sugar cravings, and mood lift.
is a mix of nonGMO fermented soy protein, yogurt powder, and enzyme-rich honey. The canister comes with a weight-loss plan.
Whey Protein Isolate, Natural Original Flavor is sourced from grass-fed cows and contains no added sugar.
Garden of Life
RAW Fit is 100% organic, raw, and vegan-and it helps to burn fat with added nutrients such as green coffee bean extract.
Plant Head Protein, Chocolate is a blend of raw hemp and pea proteins. And it tastes great!
Vegan Proteins+, Natural Vanilla is a comprehensive vegetarian formula that includes pea, brown rice, and hemp proteins.
Jonny Bowden, PhD, CNS, aka "The Rogue Nutritionist," is a board-certified nutritionist and the best-selling author of 13 books on health, most recently The Great Cholesterol Myth (FairWinds Press, 2012). Visit him at jonnybowden.com and follow him on Twitter @jonnybowden.