I don't like to complain but I have spent a lot of time learning about how to build a diet and I have never seen an article so bad in such a short amount of space.> ... new federal dietary guidelines that recommended increasing protein intake to 0.5-0.7 grams per pound of body weight—nearly double the previous recommendations. Of course, this announcement left many experts somewhat confused. For starters, American men were already consuming that much protein (around 100 grams per day) despite lower federal recommendations.
This is a non sequitur. The recommendation is for the macronutrient breakdown that constitutes a healthy diet. So it shouldn't change based on what 'experts' think the American public is already doing. That way, an American can read government's guidelines to figure out what constitutes a healthy diet vs a diet that may be very heavy in carbs or fat.
> One key factor, a hormone produced by the liver called fibroblast growth factor 21 (FGF21), ramps up when protein intake declines. FGF21 can boost the body’s energy expenditure, stabilize blood sugar levels, and reduce inflammation. In mice, at least, more FGF21 translates to a longer lifespan.
Pure unadulterated pseudoscience. Carbs cause your blood sugar (glucose) to fluctuate. Blood glucose fluctuation contributed by protein is in the noise compared to carbs. The research on this is comprehensive. Better yet, you can test this on yourself with a continuous glucose monitor. Eat 400 kcal steak/chicken/whey one meal and 400 kcal rice/bread/pasta for another. The latter will give you a big blood glucose spike.
> growth-promoting methionine, isoleucine, and valine can lead to more inflammation, obesity, and age-related diseases, the researchers say. “These studies show that the amount of protein sedentary people are eating today may have negative health consequences, at least at the population level,” Lamming explained.
Amino acids can't 'promote' obesity. Obesity only comes from sustained calorie surplus. Once you are obese, you will suffer from all sort of things that will rapidly age you (chronic inflammation, arterial plaques, hepatoxic visceral fat, insulin insensitivity leading to diabetes and so on). No honest biologist would declare a causal link from amino acids to aging without controlling for obesity.
> More exercise and metabolic activity could very well mean you need more protein, not less. “Recent recommendations have encouraged people to eat more protein, but they’ve also encouraged people to exercise more,” Lamming added. “We probably need to personalize protein recommendations based not just on age, but also on how physically active people are.”
There is no reason to be coy about this because it has all been researched. 0.5-0.7 is fine for everyone including athletes. Some body builders push it to 1g/lbs, but explaining why they do this is a complicated topic. You can safely eat less than 0.5g/lb because carbs and fat have a protein sparing effect. The biggest benefit to more protein than strictly necessary is that they make meals filling, whereas fat is calorie dense and (high GI) carbs can make you hungry again quickly.