BEIJING, May 19 (Xinhua) — In the early 20th century, Arctic explorer Vilhjalmur Stefansson ate only meat and no other meat for a total of five years, containing 80 percent fat and 20 percent protein, according tomedia reports. Twenty years later, in 1928, he repeated the practice by conducting a year-long experiment at Bellevue Hospital in New York.
Stephenson wants to refute the notion that “humans can’t survive only meat.” Unfortunately, in two attempts, whenever he only eats lean meat and no fat, he quickly falls ill and suffers from “protein poisoning” (a.k.a. “rabbit hunger”). But when he reduces his protein intake and increases his fat intake, the symptoms will disappear. After he began eating protein-rich foods, he found his health deteriorating and had to return to low-carbon, high-fat, high-protein eating habits until his death at the age of 83.
His early experiments were one of the few cases in which high protein intake produced extreme side effects. Today, despite growing sales of protein supplements, many people still wonder how much protein they need, what is the best way to eat, and whether it’s dangerous to consume too much or too little.
Many people eat sports nutrients such as protein bars and protein shakes.
Although obesity rates have doubled in the past 20 years, we are becoming more aware of what we eat. In recent years, many people have started to replace white bread with whole-wheat bread and skimmed milk instead of whole-fat milk. Protein is at the heart of this health campaign. Protein balls, protein bars, and all kinds of regular foods that add extra protein occupy an important place on supermarket shelves. The global market value of protein supplements in 2016 was about RMB80 billion, indicating that we are increasingly embracing the term “the more protein we consume, the better”.
But now some experts point out that foods that are deliberately high in protein (and at a price) are a waste of money.
Protein is essential for the body’s growth repair. Protein-rich foods such as dairy products, mince fish and legumes break down into amino acids in the stomach, which are then absorbed by the small intestine, from which the liver filters out the amino acids the body needs, and the rest is excreted with urine.
Adults with general activity are advised to consume 0.75 grams of protein per kilogram of body weight per day. On average, it’s 55 grams for men and 45 grams for women, about the size of two palms of meat, fish, tofu, nuts or beans.
Insufficient protein intake can lead to hair loss, acne, and weight loss due to muscle loss. But these side effects are rare and usually only occur in people with eating disorders.
However, most people have been associated with protein and muscle growth. This is true. Strength training causes proteins in the muscles to break down. To make the muscles stronger, the protein in the muscles needs to accumulate again. A class of amino acids called leucine plays a particularly important role in stimulating protein synthesis.
Some experts have even suggested that if you don’t add protein after exercise, you may break down more protein than you can synthesize, meaning that muscle mass cannot increase. Protein supplement brands recommend drinking protein shakes after fitness to promote the growth and repair of muscle tissue. Most of these supplements are lheinine-rich whey protein, a by-product of the cheese making process.
Studies do show that the muscle-boosting effects of various protein supplements vary. In 2014, an analysis of 36 papers showed that protein supplements had no effect on the muscle mass and strength of untrained subjects in the first weeks of endurance training.
And as training becomes more difficult, protein supplements do promote muscle growth. But the paper concludes that these changes have not been proven in the long term. A 2012 paper further states that protein “improves physical performance, promotes post-exercise physical recovery, and increases ‘thin weight'” … But for the best results, you should also combine quick-acting carbohydrates.
But even increasing protein intake after exercise may be beneficial to athletes and fitness professionals, it doesn’t mean they should take protein supplements and milkshakes. Most people get more protein from their food than they do with their daily recommended intake. No one needs to take supplements. It is convenient to get protein in this way, but none of the ingredients in the supplement can be consumed through food. Protein nutrition bars are just candy bars that add a little more protein.
Even for bodybuilders, products such as whey protein are blown out of the name. People are too focused on what kind of supplements they should take, rather than actually walking into the gym and increasing the amount of exercise. There are many variables in life, such as sleep, stress and eating habits, which can affect fitness.
Most experts agree that protein is best obtained from food rather than supplements. Older people can also benefit from the intake of extra protein. Because as the body ages, we need more protein to preserve muscle mass. But older people tend to cut down on protein intake because older taste buds are more sweet than fresh taste. Older people should increase their daily protein intake to 1.2 grams per kilogram of body weight.
Fortunately, it’s hard to get too much protein. Although there is a cap on protein intake, it is “almost impossible to achieve”. Some dietitians worry that a high-protein diet may be harmful to the kidneys and bones. But there is little sign of that in healthy people. If someone already has kidney disease, eating a lot of protein may be a problem, but the probability of side effects is very low.
However, while the protein itself is harmless, many protein supplements contain a large amount of Fodmaps (a short-chain carbohydrate found in natural ingredients or food additives), which can cause digestive symptoms such as bloating and abdominal pain. People should carefully read the labels on protein supplements or protein bars. They tend to be high in calories and contain a lot of carbon water, mostly in the form of sugar. Their high protein content does not mean they are healthy foods.
Protein has long been associated with weight loss. The so-called “primitive diet”, “Atkins diet” and other low-carbon water, high-protein diet all try to extend the duration of satiety. People lose weight often because of hunger, and MRI studies show that a protein-rich breakfast helps suppress appetite for the rest of the day.
There is ample evidence that protein contributes to a feeling of satiety. So if you want to lose weight, you should eat a lot of protein for breakfast. But a rush to reduce carbon water intake can have side effects on intestinal health, which we know is critical to the overall health of the body.
Instead, overweight people should adopt a diet of high-protein, moderate lyave, which should contain 30 percent protein, 40 percent carbon water and 30 percent fat. In contrast, the proportion of these three ingredients in the general diet was 15%, 55% and 30%, respectively.
Of course, increasing your protein intake alone won’t help you lose weight. Choosing lean meats such as chicken or fish is key. Studies have also shown a link between high intake of animal protein and weight gain, and a particularly significant association between red meat and an increased risk of cancer and heart disease.
Healthy proteins are not necessarily obtained from meat, such as those extracted from bacteria. The researchers are analyzing the effects of a combination of protein and cellulose on satiety and insulin levels. A team of researchers compared a diet based on bacterial protein with a chicken-based diet and found that subjects who ate vegetarian meat needed less insulin to secrete when they reached the same sugar-control level.
The risk of overeating protein is low, but the risk of blindly buying high-priced products in order to increase protein intake is not. Some product labels have high protein content, but in practice they are not, and they are quite expensive to sell. In any case, consuming more protein than your body needs is a waste of money and ends up being flushed out of the toilet. (Leaf)