Principle #2: Protein is the most important macronutrient to get right.
Why? Two reasons.
Reason #1: It helps you eat less, without feeling so hungry.
Research consistently shows that protein helps you feel full longer and, as a result, lose weight.
That’s, in part, because it takes longer for the body to break down protein than carbs or fat.
Protein also stimulates the release of satiety hormones in the gut.1,2
So when you eat protein, you naturally tend to eat less.
And it makes a big difference. Doubling your protein intake could help you to spontaneously consume 400 fewer calories a day. For reference, that’s roughly the number of calories in 1 ½ cups of ice cream
Reason #2: Protein makes it easier to build and maintain muscle.
Without adequate protein, our bodies just can’t function well. We need amino acids (protein’s building blocks) to produce important molecules like enzymes, hormones, neurotransmitters, and antibodies.
So when we don’t eat enough protein, our bodies plunder it from elsewhere, like our muscles, resulting in muscle loss.
This is especially true if we’re eating fewer calories than we’re burning.
On the flip side, a high-protein diet seems to maximize muscle protein synthesis, which should lead to more muscle gain for people who are strength training and consuming enough calories.
This is probably one of the reasons high-protein diets are better for improving body composition than normal or low-protein diets.
A review of 38 studies found that, for people who are out of shape, consuming extra protein won’t magically build any muscle—no surprises there. But for people who are really pushing themselves in the gym, eating more protein seems to boost their results, helping them gain even more muscle.4,5
What does this mean for you?
The right amount of protein for each person varies on a number of factors such as age, gender, and goals.
Someone interested in packing on muscle for a bodybuilding competition might aim for as many as 50 grams of protein (or about two palm-size portions of meat) at every meal. Someone hoping to work off 20 extra pounds is going to need much less than that.
References in principle 5