“People think carbohydrates are the enemy, protein is your friend,” said Eleanor Dwyer, research analyst at the company, and “any health problem is overkill.”
Experts note, however, that there is only a limited amount of protein the body can use. “The body only digests and absorbs a certain amount of protein with each meal,” about 20 to 40 grams, said Jim White, dietitian and exercise physiologist who spoke on behalf of the Academy of Nutrition. and dietetics. “People think that if they get their fill of protein, it will be a silver bullet, whether it’s for weight loss or for getting fit and building muscle, but that’s not true.”
“You can eat 300 grams of protein a day, but that doesn’t mean you’ll gain more muscle than someone who eats 120 grams a day,” White said. Meanwhile, “you are depriving yourself of other macronutrients that the body needs, such as whole grains, fats, and fruits and vegetables.”
Short-term studies suggest that diets high in protein and low in carbohydrates may promote weight loss and help maintain lean muscle mass, and that eating protein helps satisfy hunger. But a recent small trial found that older women who lost weight on a high protein diet failed to experience one of the important benefits that usually follow weight loss, improved insulin sensitivity. , which reduces the risk of developing type 2 diabetes. Large studies also suggest an association between usual high protein intake and an increased risk of diabetes.
Doctors are also concerned about the long-term effects of maintaining a high-protein diet. Studies show that high protein diets do not preserve muscle mass in the long run, and doctors have long warned that a high protein diet can lead to kidney damage in those with silent kidney disease by putting on a extra pressure on the kidneys. According to the National Kidney Foundation, up to one in three Americans is at risk for kidney failure from high blood pressure or diabetes.
In addition, some researchers are concerned that the muscle-building properties that consumers look for in protein could be a double-edged sword, possibly even leading to an increased risk of cancer.
“One of the benefits and concerns about a high protein intake, especially animal protein, is that it tends to speed up cell multiplication,” said Dr Walter Willett, chairman of the nutrition department of the Harvard TH Chan School of Public Health. “It’s good early in life when you’re a growing child. But later in life, it’s one of the basic processes that increase the risk of cancer. “