Protein shakes, drinks, bars, powders, and supplements - the ‘protein’ craze has captured the entire fitness industry and made it into mainstream nutrition. Even everyday breakfast cereals are touting their protein content. With so much buzz about proteins, it is imperative that we understand this ‘desired’ macronutrient well.
Whether it is in skin, hair, muscles, nails, hormones, or vital organs, proteins are everywhere. Necessary for maintaining the structural components of our body, synthesizing neurotransmitters, improving immunity, and producing enzymes, proteins are rightly known as ‘the building blocks’ of life.
The physiological role of proteins in our body is complex and critical. They are needed for promoting growth (during childhood and adolescence), facilitating movement (they support connective tissues present in bones and ligaments), fighting infections (by creating antibodies), transporting oxygen and nutrients across cells (through hemoglobin in blood), and regulating the acid base balance (they serve as buffers and maintain pH of blood).
Protein and Amino Acids
Each protein molecule is comprised of organic compounds called amino acids. The body needs amino acids to break down food, grow, and repair tissue - among other things. Amino acids are classified as essential, non-essential, and conditional amino acids.
Essential amino acids must be supplied through food sources - as the body is unable to synthesize them on its own.The nine essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Non-essential ones such as alanine, asparagines, aspartic acid, and glutamic acid can be synthesized inside our body from essential amino acids.
Conditional amino acids are needed only during episodes of illness or acute stress. They include: arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine.
Complete and Incomplete Proteins
Protein sources in a diet can be labeled as complete or incomplete proteins, according to how many of the essential amino acids they provide. The protein contained in foods such as meat, milk, eggs, and fish are considered complete protein sources, as they provide all of the essential amino acids.
An incomplete protein would be a food source that is low in one or more of the essential amino acids. Incomplete proteins include beans and nuts. Combining two incomplete protein foods together, however, such as eating rice (which contains high amounts of lysine and less of methionine) along with beans (which are high in methionine and low in lysine), can provide the body with all the essential amino acids. Such food sources are called complementary proteins.
These kind of proteins allow us to meet our protein needs without always having to rely on meats. Recent studies prove that even vegans can get their recommended protein needs without meat, as long as they eat a variety of healthy foods every day.
Lean vs. Fatty Proteins
If you're trying to build muscle nor cut calories for the swimsuit season, select protein foods with a low amount of fat per serving. USDA lists all foods made from meat, poultry, seafood, beans, peas, eggs, soy products, nuts, and seeds as part of protein food group. By rule, the plant based sources, however, are lower in fat and hence considered lean. Meat lovers, however, not need fret - as there are lean versions among animal foods as well. Seafood such as salmon, anchovies, herrings, sardines, and mackerel provide adequate protein and also a range of nutrients, most notably the heart friendly omega 3 fatty acids and minerals.
Other good sources of lean protein include white meat chicken and turkey, egg whites, “round” or “loin” beef cuts, yogurt, low-fat dairy, lentils, soybeans, and nuts.
Benefits of Protein
A Journal of Nutrition study reports that when it comes to satiety, protein has more staying power than carbohydrates and fat. Eating a moderately high protein diet helps curb hunger and makes us feel more satisfied. Scientific studies relate consumption of lean protein to improved muscle mass, better carbohydrate metabolism, and lowered blood lipid levels.
Pairing moderate intake of lean proteins with customized strength training exercise programs further helps you lose weight effectively, says a study published in Journal of Nutrition. Any protein source containing the amino acid leucine works with insulin to burn fat, boost metabolism, and promote muscle growth.
How Much is Enough
The exact amount of protein needed per day depends on the age, gender, activity level, and health of an individual. That said, two to three servings of protein are usually considered enough to meet the daily protein needs of the average person. The American Dietetics Association recommends that 10-25% of your daily calories come from proteins.
This works out as approx 45-60 gms of protein per day for an adult. While proteins are essential to health, filling up on extra proteins - more than 30% of your daily caloric intake - could actually harm your body. Consuming too much protein may cause a buildup of toxic ketones, which can thrust our kidneys into overdrive in an attempt to flush them out. This can make us dehydrated, dizzy, weak, or lead to more serious health problems.
The Bottom Line
The protein fad has skewed our perception of how much protein we actually need. Make sure you're not falling victim to ads telling you that you need more protein in your diet. It's more likely that you're consuming too much. The key is to select a variety of lean protein foods, eat them in moderation, and team them up with a physically active lifestyle and balanced diet to feel satisfied, build strength, and maintain a healthy weight.
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