If the human body had an ingredients label, the second ingredient, after water, would be protein. The word protein is derived from Greek words meaning “of first importance.” Protein is the basic structural material of all organ and tissue cells. There are also many biologically active proteins in the body, including enzymes, antibodies, hormones, neurotransmitters, nutrient transport and storage compounds, and cell membrane receptors. In addition, amino acids released from proteins can serve as direct and indirect energy sources, although this is not their preferred use except in a few cases (e.g. glutamine in the gut).
Lately, protein has gained new attention due to research demonstrating that a high-protein diet reduces appetite and eating and promotes fat loss. This new research is particularly exciting because permanent fat loss can only be achieved if calorie intake is reduced in a way that does not produce persistent hunger. Switching to a high-protein reduced-calorie diet now appears to be one way to attain this balance. Gram for gram, calorie for calorie, protein produces more satiety (fullness) than either carbohydrate or fat. Therefore, by increasing the number of calories you get from protein at the same time you reduce the total number of calories you consume in a day, you can avoid hunger and more easily stay consistent with your diet, so that fat loss becomes permanent.
In a recent study from the University of Washington School of Medicine, 19 subjects were fed each of three diets sequentially. For two weeks they followed a weight-maintenance diet comprising 15 percent protein, 35 percent fat, and 50 percent carbohydrate. For the next two weeks they followed a high–protein diet of equal calories. The macronutrient breakdown of this diet was 30 percent protein, 20 percent fat, and 50 percent carbohydrate. Finally, the subjects switched to a high-protein diet with the same macronutrient breakdown but no calorie restriction—subjects were allowed to eat as much or as little as they pleased (or “ad libitum”). They stayed on this last diet for 12 weeks.
The authors of the study reported that when subjects switched from the low-protein weight maintenance diet to the high-protein weight maintenance diet, they started feeling much fuller despite the fact that they were consuming the same number of calories. Even more significant, during the unrestricted high-protein diet phase, the subjects voluntarily reduced their daily eating by 441 calories per day and lost almost 11 pounds, including more than eight pounds of body fat, on average.
Based on recent studies such as this one and other new protein research, here are some basic protein intake recommendations:
Get 30 percent of your calories from protein.
The Average American diet is roughly 18 protein. This is not enough protein to reduce your appetite. To take full advantage of the hunger-killing benefits of protein, you need to consume the same amount of protein as the subjects in the study cited above: 30 percent of your daily calories. You can easily increase your protein intake from the average level to the 30 percent level by consuming three Permalean snacks per day; any combination of Permalean shakes and Permalean bars will do.
For example, if you’re currently eating 2,000 calories per day, then you’re probably consuming approximately 90 grams of protein. To get 30 percent of your calories from protein, you need 150 grams of protein daily. Each serving of Permalean contains 20-21 grams of protein. Three servings provide 60 grams of protein. Add that to the 90 you’re already eating by replacing low-protein or non-protein snacks and meals you’re currently eating and you have 150 total grams. Of course, to lose weight you need to consume fewer total calories than you are now, but this will happen automatically due to reduced appetite, just as it did for the women in the University of Washington study.
Get most of your protein from animal sources.
Animal foods (meat, fish, eggs, and dairy) are better protein sources than plant foods (vegetables, grains, legumes) for three reasons. First, animal proteins are more bioavailable than plant proteins. Only 78 percent of the protein contained in high-fiber legumes is actually digested, compared to 97 percent of the protein contained in animal foods.
Second, animal foods provide complete proteins, whereas plant foods do not. A food is considered a complete protein source when it contains all nine amino acids. There is not a single plant food that qualifies as a complete protein source. That’s why nutritional studies have shown that providing an all plant-food diet to animals usually leads to muscle atrophy. Without either the ingestion of lean animal proteins or fortification of missing amino acids, the muscles are literally eaten up to provide the missing amino acids for other uses in the body.
Finally, and not least important, animal foods tend to contain much larger amounts of protein than plant foods. For example, a large (1-cup) serving of brown rice contains only 4.5 grams of protein. By contrast, a small (3-ounce) serving of beef flank steak provides nearly 23 grams of protein.
Choose lean (i.e. low-fat) protein sources.
Some protein sources are high in fat while others are low fat. Choose those that are low in fat. These include skinless chicken and turkey breasts, fish, lean cuts of beef, egg whites, non-fat dairy products, and Permalean protein shakes and bars.
Consume protein after exercise.
The most beneficial time to consume protein in the entire day is within one hour after your workout. Exercise breaks down muscle proteins and triggers the release of hormones that create a strong demand for protein within your muscles. If you consume protein within the first hour after your workout is completed, your body will build new muscle proteins more effectively than it can at any other time. These new muscle proteins will then eat your body fat throughout the day, to maintain themselves.
